u.^ III]. COIL L^DIiAKit K\AC CORNELL UNIVERSITY COLLEGE OF ARCHITECTURE LIBRARY NAC 6827'™2P9™""^ ""'"^ 3 1924 024 416 103 Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924024416103 Proposed NuivicipdLt Improvements for HdLrrisburg, Pa. REPORT OF EXECVTIVE COMMITTEE to Subscribers to Fund for IliVieifi^tmg Municipa.! Improveittents, Nov. 21, I90t ;fwi"za:Ti;iiT:z:Ji i h r ri iL 11 JJWtSHTUWTCS Cwn, «■» Saniurt CwftiNtti* MAP OF THE CITY OF HARRISBURG PENN SHOWING EXISTING AND PROP SEWERS Scale of Feet IM « MB «a» VM tiisling ^vfrs ^hown iDul Propoiea Sewers for Mouse Dra»n«|e shown ihus Proposed Sewers lor Storm Water andhouieOromage shoi Manholes siown thus • ''lush Tanks snown thus Areas tmieo red indKate general loctttionsof built up p InoiviOuai DuiiOings not snown 3 '•••- "i ^■■■■::i .\,Jn»^^^^^'r 1 i. j J. i LjJ [jj LJ J U.lrl J'. J l.Jl.Jljl.J ULJ__ I -IL 1^ 8 /Z/UL^ L J U LJ pure IX MMWUNMn — ,1 h "^ ^ ii M '-tiVv^^^^^i^ \nnV«*Ki uiiP^siv^ ^ Iftlff^crpl '>t^»»f i »w ^ otdLJLjyuL H...1 1 i '.■ ; i .V K.. jn**m*9.: ?a;3nrTGrznczx..:iRZJSZX^ mmvnw.: ...... • — -» -• ' -"- A • - MAP OF THE CITY OF HARRISBURG PENNSYLVANIA SHOWING EXISTING AND PROPOSED SEWERS Scale of Feet Ciisung Sewers shown thus ^-^^ Propo4e« Sewers for House Oratnage shown thus ' ' Proposed Sewers lor Storm Water and House OratfWje Shown Oiy» ^— • Manholes shown thus ^^^" ^Oi» rtysh tanks Shown thus ^— ^ Areas nniea red ind»cate general locaDons of built up portions oTcitjr Individual OwiiQings not shown PROPOSED MUNICIPAL IMPROVEMENTS FOR HARRISBURG, PENN'A. REPORT OF EXECUTIVE COMMITTEE TO THE SUBSCRIBERS TO JTlND FOR INVESTIGATING MUNICIPAL IMPROVEMENTS, NOVEMBER 21, 1901, EMBODYING REPORTS AND RECOMMENDATIONS OF EXPERTS EMPLOYED INCLUDING James H. Fuertes, of New York Engineer for Filtration and Sender age Warren H. Manning, of Boston Park Improvements M. R. Sherrerd, of Newark, New Jersey " Engineer for Paving HARRISBURG, PA., P JBLISHED BY THE EXECUTIVE COMMITTEE 1901 CONTENTS. PAGE. REPORT OF EXECUTIVE COMMITTEE: I. Recommendations in regard to Paxton Creek, Water Supply, Improvement of River Front, Sewerage System 3 II. Recommendations in regard to Parks 4 III. Recommendations in regard to Paving ....•■ 7 IV. Recommendations as to Ordinances desired 10 REPORT OF JAMES H. FUERTES On Water System, Sewerage, etc 13 Summary of Recommendations 14 Introductory 14 Improvement of the Sanitary Condition of and Prevention of Floods from Paxton Creek 17 Improvement of Water Supply of Harrisburg 36 Improvement of the Sewerage System of Harrisburg 58 Improvement of the Sanitary Condition of the Susquehanna River Front at Harrisburg 65 APPENDICES : I. Population of Harrisburg 74 II. Typhoid Fever Statistics of Harrisburg 74 III. Mechanical Analyses of Sand suitable for Filtration Purposes. 75 IV. Unit Prices and Depreciation Table 77 V. Turbidity of the Susquehanna River Water at Harrisburg . 78 REPORT OF WARREN H. MANNING ON PARK IMPROVEMENTS: Landscape Features 81 Small Parks and Outlying Reservations 82 The Great Country Park ... 83 The Front 85 Acreage and Cost .... 86 Control of Parks . . 88 Appendix 89, 90 REPORT OF M. R. SHERRERD ON PAVING: Kinds of Pavements 91 General Cross-Section 95 Curb-Stone 96 Street-Car Track Construction 97 Catch Basins 98 Specifications 101 Conclusion 135 !2 PROPOSED MUNICIPAIv IMPROVEMENTS. I. The report of Mr. Fuertes is not only a very complete, but a very elaborate one. It treats, First, of the improvement of the sanitary condition of and the prevention of floods in Paxton creek; Second, the improvement of the water supply of the city; Third, the improvement of the sanitary condition of the Susque- hanna river front, and Fourth, the improvement of the sewerage system with recommendations as to the proper policy to be fol- lowed in future extensions. All of these subjects, although closely allied, are very elaborately discussed in detail and your Committee does not deem it necessary to do more than refer, in a general way, to the conclusions which Mr. Fuertes has reached indicating such recommendations as it has deemed proper to make, after a thorough consideration of all the subjects discussed. A careful examination of the report in connection with the maps and plans submitted will enable any one to understand the scope of Mr. Fuertes' discussions as well as the recommendations which he has made. As covering the entire subject committed to him, he recom- mends : 1. That Paxton Creek "be retained in its present channel, as an open stream, that its section be enlarged, its bed deepened, its slope steepened, and that the dry weather flow or sewage now go- ing into the Creek be diverted into an intercepting sewer five feet in diameter, reaching from Schuylkill street to the Susquehanna River at Tuscarora street," at an estimated cost of $249,700. 2. The construction of "a rapid filter plant of a daily capacity of ten million gallons, using the present reservoir for sedimenta- tion purposes, and building a new seven and one half miUion gal- lon reservoir for filtered water, near the site of filters," at an esti- mated cost of $279,000. 3. The improvement of the sewer system by establishing "the combined system for the territory draining toward the Susque- hanna River, and the separate system for all future extensions in the territory draining to Paxton Creek from the hills on the east side of the valley. For the part of the side west of, but draining into, Paxton Creek, he recommends the combination system, the sewers to be arranged so that the dry weather flow will go into SEWeEAGE, 3 an intercepting sewer, and the storm water overflow into Paxton Creek." In connection with this branch of the general subject, he recom- mends that the general sewerage system now installed be im- proved by re-constructing all sewers which are First, of insuffi- cient capacity; Second, too near the surface, and Third, in gen- erally poor condition. He notices in detail the particular sewers requiring reconstruction, the defects which are incident to the present system, and the scope of the work necessary to place it in the best possible condition in accord with the most improved- theories of construction. The estimated cost is $77,256.40. 4. The improvement of the sanitary condition of the river front by erecting a low dam, four and one-half feet in height, at Conoy street, so constructed as not, in any way, to impede the flow of water or the sewage at present carried by the river. By the con- .struction of this dam, he shows that slack water will be created at low stages of the river as far up as Maclay street ; that by thus deepening the water on the river front all the sewers emptying into the river will be well covered at the lowest stages of water, that all disagreeable odors and unsightly conditions will be removed, and that the construction of such dam will not in any way impede navigation or obstruct the natural flow of the water. The esti- mated cost of this improvement is $55,000. The entire cost of these improvements, as recommended by Mr. Fuertes, iis $660,956.40, which in view of the importance as well as the completeness of the work, and the results to be accom- plished, your Committee are gratified to be able to say, is much below what they had anticipated. Your Committee has given careful study to the recommenda- tions of Mr. Fuertes in the concrete as well as in detail, and they are of the opinion that, if carried out as recommended, they will relieve the city from the dangerous conditions which now obtain with reference both to the water supply and the sewerage system now in Operation. It is obvious that the present bad conditions, particularly with respect to sewerage, will be dangerously increased by the aban- donment of the Pennsylvania canal and the discharge into Paxton Creek of the sewage which has heretofore gone into the canal, so that prompt and radical action upon the lines suggested is not only necessary but of vital concern to every man, woman and child in the city. 4 PROPOSED MUNICIPAL IMPROVEMENTS. Taking into consideration the magnitude of the work and the important results which must flow from it, they are of the further opinion that the expense is within most reasonable limits. Without, therefore, discussing the matter further, and without attempting to analyze the estimates for the several works, all of which appear to have been most carefully considered, as well as discussed by Mr. Fuertes, your Committee recommend the adop- tion of his recommendations as suggesting the most feasible methods by which the unsatisfactory and dangerous conditions at present existing, with respect to both the water supply and sew- erage of the city, can be remedied, and the best results consistent with local environments be satisfactorily obtained. II. The report of Mr. Manning, whilst dealing with a subject which appeals to an entirely different sentiment from that suggested by the report of Mr. Fuertes, is well worth careful and considerate at- tention. It relates to the subject of Parks and is intended to cover a comprehensive park system for the entire city. The phenomenal increase of population in the United States is almost entirely urban, so that, it is apparent, that in the future, the great mass of population will live in cities. The average cit- izen who has made his home in a city has the right to expect, and is entitled to enjoy, the best conditions with respect to health and general welfare, that the environment in which he lives^ will per- mit. He is not satisfied, and indeed ought not to be satisfied, with anything less, and no city of the present day can answer the rea- sonable demands of the citizen in that regard unless it has estab- lished and maintains, so far as existing conditions will permit, a system of public parks and play-grounds, in which the entire com- munity will have an interest. A study of Mr. Manning's report will show that it is made sub- stantially upon these lines. His recommendations embrace a comprehensive system of parks, play grounds, walks and drives, which, if it were possible to fully carry out, would render the city of Harrisburg as attractive in that regard as any city in the coun- try. He shows how the river front, which is exceptional in not be- ing obstructed by railroads, manufactories, etc., can be utilized by the establishment of small play-grounds for the children, with improved and shaded walks extending from Paxton to Maclay PARKS AND PLAYGROUNDS. 5 streets, and thus afford a never ending source of recreation and pleasure to the entire community. He recommends the acquisition of the entire river frontage, together "with the smaller islands in the river, including the east- ern shore and two ends of Hargest's or Forster's Island." In the southern section of the city, he recommends the acquisi- tion of what is known as the George F. Mish property, between Paxton and Cameron streets, and the wooded creek valley below it, which in his opinion, with "its splendid view, the fine trees sur- rounding it and the rich soil, would form an ideal site for a small park." He also recommends the extension of Reservoir Park, so as to include "the whole summit of the ridge and about one-half of the northerly slope, down to a point where a plantation would shut out the immediate foreground of houses in the valley," connect- ing it with the proposed filtration farm, which would then become a part of the Park System. In the development of the general system, he suggests the con- trol by the city of "the wooded bluffs of Paxton Creek valley, and enough of the banks of the Creek to preserve the trees," utilizing these for the construction of walks and drive-ways where possi- "ble, so as to connect the various parts of the general system, as shown upon the plans submitted. For the Northern part of the city, he says, "The opportunity ior a great country park at Harrisburg lies to the north of the city in the tract known as Wetzel's swamp, which includes about five hundred acres of swampy and dry land, framed in with wooded "bluffs on the one side, and a line of fine old willows along the canal on the other. As it stands to-day it is a natural park with beau- tiful passages of landscape, and fine vistas, over great stretches of meadow land to distant hills beyond. It is rare, indeed, that a city can secure a property having all the elements of a park landscape, its border-planting of fine trees, splendid individual specimens, and woodlands carpeted in spring with numerous wild flowers. "Here, also, there is a comparatively level and perfectly dry up- land, that, with but little clearing and the removal of pens and sheds, can be made available for picnics and games. In the mea- dows, masses of brilliantly colored flowering plants, which the up- land cannot produce, are found, giving color effects, at different seasons of the year. This region is quite accessible by steam and 6 PROPOSED MUNICIPAL IMPROVEMENTS. electric cars, and there are roads, at severa!! points, across the meadow and for a long distance along the boundaries. The swampy condition which prevails upon much of this land can be remedied, for there is abundant fall for all drainage through Fox's run and Paxton Creek." The system proposed by Mr. Manning also includes an outlying- drive of thirteen miles, extending to the country road at the ex- treme end of Wetzel's swamp, and thence eastwardly along the bluffs to the city park ways and back to Cameron Creek. The purpose of this proposed road, as will be seen from the report, is not only to furnish a beautiful drive-way, but also to connect the various parts of the comprehensive Park System which he recom- mends. Your Committee has gone over most of the ground which is intended to be included in the proposed Park System, and have been much impressed with its comprehensive character, as well as with its natural beauty, and with the comparatively small ex- pense for which it can be carried out. Manifestly the financial condition of the city will not at present permit the carrying out of Mr. Manning's system in all its detaiils. A substantial beginning, however, can be made, and your Com- mittee recommend that proper steps should be immediately taken, to at least acquire some of the locations which are essential to the carrying out of the system. Assuming that the improvements in respect of the Water and Sewerage System can be effected at a cost not exceeding the amount estimated, there will still be an available margin within the constitutional limitation of debt, which could be applied to the- beginning, at least, of a comprehensive Park System. This might properly involve the acquisition of the Mish property, and a por- tion of Wetzel's Swamp, the proposed extension of Reservoir- Park, and the control of the banks, as far as possible, of Paxton creek, and the adjacent wooded bluffs, together with such im- provement of the river front as may be necessary to adapt it more fully to the purposes of a public park. Under an Act of Assembly, approved May nth, 1901, the cities of the Commonwealth are authorized "to purchase, acquire, en- ter upon, take, use and appropriate private property for the pur- pose of making, enlarging, extending and maintaining public parks, within or without the corporate limits of such cities, whenever the councils thereof shall, by ordinance or general resolution, de- ROAD CONSTRUCTION. 7 termine thereon : Provided that where said property is outside of the city, it may be annexed thereto by ordinance of sucli city." Under this Act, the City Councils could at once take such ac- tion as would at least inaugurate a beginning of the Park System recommended, so far as the financial conditions of the city will per- mit. If this were done, a natural development would necessarily follow, -and in a few years the city of Harrisburg would be pos- sessed of a Park System which would rival that of any other city of its size in the country. By another Act of the Legislature, passed May 17th, 1901, the charter of cities of the third class was so amended, as to authorize the creation of "Any office, public board or department," which councils "may deem necessary for the good government and in- terest of the city, and to prescribe the powers thereof." Under this Act, a Park Commission could be created, which could take title to and control all the property which it might be found neces- sary or feasible to acquire for park purposes, and this of itself would be a substantial commencement of the work. Your Committee, therefore, recommend that Mr. Manning's report as a whole be adopted, and that such action be taken by the proper authorities as will inaugurate the proposed Park System and enable the city to acquire control of the neces- sary property, and at the same time, to create a Board of Public Parks, with such powers as may be necessary, to develop the sys- tem, with a view to eventually carry out the comprehensive plan proposed by Mr. Manning. III. The report of Mr. Sherrerd treats of Pavements and the proper methods for their construction and repair. It is accompanied by plans and elaborate specifications, from which any citizen can see for himself, what kind of pavement may be proper for any given locality, how it ought to be constructed, and the relative cost of each kind. For purely residential streets he recommends macadam pave- ment, varying in depth, according to the traffic to which it may be subject; for streets where the traffic is heavy and very much congested, he recommends granite block pavement, as the most "durable and at the same time most serviceable in all kinds of weather ;" for some of the business and residential streets he rec- ommends asphalt pavement on a concrete base, and a brick pave- 8 PROPOSED MUNICIPAI, IMPROVEMENTS. ment on a concrete foundation for such streets as Mulberry and East State streets. In discussing the general subject, he says, "It is not well to lay asphalt on streets that have an exceptionally light traffic, as this pavement needs a moderate amount of traffic to insure its life." He suggests that brick pavements are more suitable than asphalt for streets having a heavy grade ; that in cases where streets have been more or less macadamized, the macadam now existing may be used to advantage on the street, in the preparation of the foun- dation for a more improved pavement, and that in some cases a combination of brick and asphalt pavements may be used to ad- vantage, as for example on Thirteenth and Derry streets. Speaking of asphalt block, he says, "When well laid it has given satisfactory results. I believe, however, that it should only be laid on such grades as will entirely prevent water from standing on the pavement at any point. You have some fairly good examples of this class of pavement, but my experience has shown that when- ever a slight depression exists to hold water for any length of time the blocks at this point begin to disintegrate." Mr. Sherrerd's report gives special attention to methods of con- struction, including street car track construction, catch basins and such details as are necessary to secure the best results. He also discusses the several kinds of pavement, not only those recom- mended, but others which are in use showing the advantages and disadvantages of each, so that, by a careful study of the report, an intelligent conclusion can be reached by any one, with respect to the desirability of any kind of pavement. In this connection, he says, "Granite block, though the most durable pavement, is very objectionable on account of its rough surface and the noise resulting from its use. It is also difficult to keep this pavement clean. Its use should be confined exclusively to business or manufacturing districts, or where exceptionally heavy traffic is confined to narrow limits." "Asphalt pavement, when properly laid, is no doubt the most satisfactory pavement for city streets. It should also be kept scrupulously clean. The street filth, being ground to a fine pow- der upon its surface, is particularly objectionable and penetrates into all crevices. Constant sprinkling and the use of much water on asphalt streets not only afiEects the Hfe of the pavement, but forms a sticky paste which is very objectionable. Many cities have found it advantageous to thoroughly flush asphalt streets at night or systematically care for them by the constant attention of PAVEMENTS. 9 a man to a section, the length of the section depending upon the amount of trafiSc." "In laying brick pavements the best method of filling the joints has been a mooted question. Sand, tar and cement grout are used as fillers. Brick pavements laid with cement fillers are better than those laid with less rigid filler." Your Committee does not deem it necessary to do more than suggest an outline of Mr. Sherrerd's work. The specifications which he has submitted cover, in a most thorough manner, every possible detail, and if they should be adopted as standard specifi- cations for the several kinds of pavements suggested, it is suffi- cient to say that the city would secure the advantage, not only of the best kinds of pavement adapted to existing conditions, but the best possible construction in all its details. Your Committee, therefore, suggest that it be recommended to city councils, to adopt these specifications as a standard, in the construction of all future pavements, and that they be given such publicity that every citizen may know for himself, not only what pavement is best adapted to a given street, but may also be as- sured that when laid down, it will be constructed in the best pos- sible manner. Your Committee believes that it will be generally conceded, that the city of Harrisburg is not up to date in the matter of improved pavements. Its progress on that line has been slow, and in some respects unsatisfactory. As a result of the policy of imposing the entire cost of construction upon the abutting property owners, much dissatisfaction has been engendered, and much litigation in- curred. After a full and careful consideration of the entire subject, as an incentive to the construction of more and better paved streets, your Committee recommend that at least a portion — one-third, or perhaps one-half — of the expense of putting down a pavement for general traffic should be borne by the city. If this policy were adopted by councils, it is reasonable to believe that a general movement, in the line of better paved streets, would be inaugur- ated, and in a very short time, the city of Harrisburg would have reason to be proud of the condition of her streets, in respect of pavements at least. In this connection Mr. Sherrerd says: "For ease of traction, comfort and health, good roads and well paved streets, which will sustain the traffic and may easily be kept clean, are a necessary ad- junct to good government. Combined with well constructed pave- lO PROPOSED MUNICIPAI, IMPROVEMENTS. ments, a good general appearance, and finished look to the work should be obtained. Scarcely any other form of city government is so apt to impress the stranger visiting your city as the condi- tion of the streets. This fact, together with the obtaining of the comfort, convenience and health of your own citizens, and the making of your city a more attractive place to live, should prove an incentive for more and better streets." Your Committee is fully in accord with Mr. Sherrerd in this regard, and sincerely trust that his work will mark the beginning, at least, of a movement which will eventually secure the best re- sults in the matter of street paving. IV. In discharging the duty devolving upon it, your Committee has sought to obtain, on each branch of the subject committed to it,, the best possible engineering talent. How thoroughly the work has been done, will appear from the several reports, which with the accompanying plans, drawings, etc., are herewith submitted as a part of this report. Without discriminating it may be properly said that they will each merit the most careful study, not only by yourself, but by every citizen who is interested in the welfare and improvement of his city. With a view to inaugurate the proper movement on the part of city government, and to carry out the several recommendations of the engineers, as far as possible, your Committee suggests that councils should be requested, as soon as practicable, to pass the proper ordinances, looking to the submission to the voters at the spring election of the question of incurring the debt necessary in making the improvements contemplated. These ordinances should be four in number, and in the order of their importance are as follows : 1. An ordinance relating to the improvement of the sewerage system, including that which is now disposed of through the Pax- ton Creek and the Pennsylvania Canal. 2. An ordinance relating to the improvement of the water sup- ply, by the construction of a rapid filter plant. 3. An ordinance providing for a commission to take charge of the extension and improvement of Public Parks. 4. An ordinance relating to the construction of improved pave- ments. Your Committee has been informed that upon the present assessment, an additional indebtedness of $1,091,476.35 may be CONCLUSION. II created within the constitutional Hmitation. In estimating the present indebtedness of the city, it has been suggested that the water debt, which represents an investment rather than a debt, should be eliminated. If this could be done, a much larger in- debtedness for general city improvement could be incurred, and it is, therefore, a subject entitled to consideration by councils. It may further be properly suggested that it might be well, in order to secure the best results, that a commission on Public Im- provements should be created under the Act of 1901, to have charge of the expenditure of all moneys devoted to public improve- ment, outside of public parks. Whether the appointment of such a Commission would be desirable, is a matter for future consider- ation, but as it is within the line of the policy which your Com- mittee think should be adopted in connection with the movement for general city improvement, it is pFoper to refer to it now. A detailed statement by the Treasurer, showing the receipts and expenditure of your Committee, is also hereto appended. Respectfully submitted. PROPOSED MUNICIPAI, IMPROVIlMENTS. REPORT OF TREASURER OF THE EXECUTIVE COMMITTEE. Harrisburg, Pa., Nov. 2fth, ipoi. Thomas T. Wierman, Treasurer, in account with Fund subscribed to procure Plans for Municipal Improvements. Dr. Received from Subscribers (see list below), $5,075 00 Disbursements, viz: For services of experts $4,410 95 For office rent, furniture, light, .... 113 46 For printing reports, 533 00 For stationery and postage' 15 77 Total disbursements, 5,073 18 Balance unexpended, $3 82 List of Subscribers Contributing to the Fund. J. A. Affleck. W. K. Alricks. Edward Bailey. James Boyd. John Y. Boyd. James M. Cameron. T. G. Calder. William J. Calder. F. W. Cohen. James I. Chamberlin. Charles A. Disbrow. Miss Mira L. Dock. Daily Telegraph. A. J. Dull. Mrs. A. P. L. Dull. James J. Dull. Maurice C. Eby. W. C. Farnsworth. David Fleming. Samuel W. Fleming. W. R. Fleming. Mrs. Dr. James Fleming. John E. Fox. Lyman D. Gilbert. Mrs. L. D. Gilbert. Spencer C. Gilbert. George A. Gorgas. Edward Z. Gross. W. B. Hammond. Lane S. Hart. D. C. Haldeman. Mrs. Eliza B. Hummel. W. T. Hildrup, Jr. D. L. Jauss. Johnston & Co. Charles A. Kunkel. Mrs. E. C. Kunkel. James M. Lamberton. F. R. Leib. Howard F. Martin. Ehrman B. Mitchell. Henry B. McCormick. Mrs. H. B. McCormick. James McCormick. Vance C. McCormick. Miss Anne McCormick. G. M. McCauley. J. Horace McFarland. R. C. Neal. M. E. Olmsted. George W. Reily. J. V. W. Reynders. Smith & Keffer. Robert Snodgrass. Charles Soleliac. A. C. Stamm. D. E. Tracy. John H. Weiss. E. Z. Wallower. T. T. Wierman. REPORT ON PAXTON CREEK, WATER SUP- PLY, RIVER FRONT AND SEWERAGE Harrisburg, Pennsylvania, September 2, ipoi. J. V. W. Reynders, Esq., Chairman Sub-Committee on Water and Sewerage, Executive Committee on Plan for Public Improvements. Sir:— It gives me much pleasure to submit herewith, in response to your instructions, a report covering the following subjects: 1. The improvement of the sanitary condition of and the pre- vention of floods in Paxton Creek. 2. The improvement of the water supply of the city. 3. The improvement of the sanitary condition of the Susque- hanna River front. 4. The improvement of the sewerage system, with recommen- dations as to the proper policy to be followed in future ex- tensions. The commission, dated June 21, 1901, entrusting me with the work, placed upon me a great responsibility, in view of the short time at my disposal in which to complete the report. While I have not been able to enter into as much detail as I should have liked, I can now, after careful investigation, make definite recom- mendations, with the fullest confidence that they will in all cases show the means of obtaining satisfactory relief at a cost well within the resources of the city. My recommendations are as fol- lows : 1st. For the treatment of Paxton Creek, I find that in order to prevent the fouling of the creek it will be necessary to divert all the dry-weather flow of sewage now finding its way to the stream into an intercepting sewer to discharge into the Susquehanna River at the foot of Tuscarora street ; that to prevent floods occa- sioned by high water in the Susquehanna River is impracticable, but that floods from Paxton Creek may be prevented most cheaply by enlarging the present channel of the creek, and main- taining it as an open channel in its natural course. 14 PROPOSED MUNICIPAI, IMPROVEMENTS. 2nd. For the improvement of the water supply, I find that to secure clear pure water at all times it will be most satisfactory to install a rapid filter plant, to be operated with alum as a coagulant, and maintain the pumping station and the intakes in their present positions. Before filtration it will be most economical to provide for about twenty-four hours simple subsidence. 3rd. For the improvement of the sanitary condition of the Susquehanna River front, I find that the most satisfactory method, from all points of view, will be to construct a dam across the river, below Conoy street, the dam to be high enough to create slack water in times of low summer flow as high up the stream as Maclay street. 4th. For the improvement of the sewerage I find that the com- bined system should be employed for all sewers emptying into the Susquehanna River and into Paxton Creek from the west side of the same, while the separate system would be the best and most economical for the portion of the city lying east of the creek. I further find that certain portions of the city are inadequately sew- ered, either by reason of the sewers being too near the surface, too small, or in too poor a condition to make repairs justifiable. The details of the necessary corrective works are described in full in the following pages. The respective costs of these improvements are as follows : For the prevention of floods and the improvement of the sanitary condition of Paxton Creek $249,700 For the improvement of the water supply 279,000 For the improvement of the sanitary condition of the Susquehanna River front 55,000 For the improvement of the sewerage system 77, ^S^ Total $660,956 The reasons upon which the foregoing conclusions are based are given in full under the discussions of the different subjects, in the following report. Respectfully submitted, James H. Fuertes. INTRODUCTORY In undertaking the investigations of the subjects mentioned in your letter of instructions, it was necessary to decide at the outset the limits to which the studies should extend. Manifestly, it INTRODUCTORY. 1 5 would be impossible in ten weeks to prepare working drawings for so many and such important works. It seemed, therefore, that the principal object of this report should be to determine the proper policy to adopt in the general treatment of the different problems, leaving the working out of the details for a later time. It may be, therefore, that some of the designs upon which the estimates of cost have been based, may advantageously be changed somewhat upon a more intimate acquaintance with local circumstances and requirements. Such changes, however, would not alter the general conclusions nor greatly affect the estimates of cost. Quite a large amount of field work has been done to obtain the necessary information, and the estimates are given with the as- surance that they will prove ample to cover not only the cost of construction, but the cost of land, as well as incidental, legal and engineering expenses. They are all strictly comparable, and their totals will enable you to judge of how the different plans compare both as to cost of construction and annual cost of maintenance. The items given under the heading "Annual Cost of Mainte- nance" includp, in all cases, interest at the rate of 3-1/2% per annum, the cost of repairs, an allowance for depreciation to cover the cost of renewals, and the superintendence and labor necessary for operation. The unit prices used in making the estimates of cost and the depreciation table will be found in Appendix IV. I have not in the estimates of annual cost of maintenance and operation added an allowance for a sinking fund to retire the bond issue necessary to enable the works to be constructed, because cities can generally provide for the cancellation of bonds at ma- turity by issuing a new series bearing the same or even lower rate of interest than the series retired. This being a fact it would seem unnecessary to provide a sinking fund to retire bonds issued for permanent public improvements which are designed to serve many coming generations. A sinking fund to retire a bond issue in a short period of years throws the whole burden of payment on the tax payers in that period, while the generations following secure the benefits from the works free of cost, because at maturity inter- est and sinking fund charges both cease. In works of a temporary nature or having a short period of usefulness the situation is different, and a sinking fund charge is proper. In my estimates I have not, therefore, used a sinking 1 6 PROPOSED MUNICIPAL IMPROVEMENTS. fund allowance, but have added sums under the head of depre- ciation sufficient to replace the works as they wear out, become antiquated or unsatisfactory, the sums being calculated upon the costs of the works and the probable length of life of their com- ponent parts. The propriety or impropriety of making a sinking fund, as a point of law, would not affect the recommendations made herein, as in all cases such provision would cause the chosen plans to show still more favorably, because the sinking fund must be computed on the cost of construction, and the recommended plans are all the least expensive of the different alternatives. Another point which should be mentioned is that the cost of public water supply and lighting plants should not in reason be classed in a city's indebtedness. Such works produce sufficient revenue to pay all fixed and operating charges and are in fact money making institutions. It seems therefore that they should be exempted in ascertaining the permissible limit of bonded in- debtedness. If this were feasible in Harrisburg, the debt limit could be very considerably extended to permit of the execution of other necessary public works. The collection of the data for this report required a very con- siderable amount of work. The task was materially lightened, however, by the satisfactory responses of the various city officials to requests for information. I wish to record here my apprecia- tion of these courtesies, and particularly to acknowledge the valu- able co-operation of Mr. M. B. Cowden, City engineer, and his corps of assistants, who have placed all the records of their offices at my disposal and aided very materially in expediting the work by ready and full explanations. That this report is completed by September 1st, is owing to the fidelity and industry of Messrs. Henry N. Ogden, John T. Parson, Jonas W. Griswold, Robert L,. Burwell and Robert H. Cable, gentlemen whom I associated with myself in the working out of the solutions of the various problems. The quantity and charac- ter of the work accomplished speak for themselves. In conclusion I wish to thank the members of the Harrisburg League for Public Improvements for many courtesies and to add that should this investigation be the means of showing an easy and inexpensive way out of the various difficulties, the substantial appreciation and support of the citizens of Harrisburg are due the gentlemen whose foresight, public spirit and liberality started the movement which made the investigation a possibility. PAXTON CRg]JK, 17 THE IMPROVEMENT OF PAXTON CREEK. Paxton Creek drains quite a large area lying to the north and east of Harrisburg. Above the south line of the city its drainage area is 23.9 square miles, while about 3 miles north of State street, where the channel makes a semi-circular bend in entering the flat portion of the valley, its watershed is 16.4 square miles. The head- waters of the creek are in the foot hills of the Blue Mountains and in the rolling country near Linglestown. As the principal tribu- taries join the main stream within a distance of 2-1/2 miles of each other, all these branches, during heavy rains, discharge into the main channel at about the same time. On account of the small water way and the flat slope in the lower course of the stream the water cannot flow ofif as quickly as it comes down from the hills, and the flooding of the valley results. Sometimes a por- tion of the flood water finds its outlet through Eox's Run, but the greater part flows down through Harrisburg to the Susquehanna, doing more or less damage on the way, according to the severity of the flood. Where the stream passes through the city it receives the dis- charges from several large sewers, which, during dry weather, pol- lute the water and foul the shores and bottom of the creek to a very objectionable extent. In studying methods for the proper treatment of the creek, therefore, two points must be considered: The prevention of destructive floods, and the maintenance of the channel in proper sanitary condition. These considerations require a knowl- edge of the quantity of water flowing in the stream during the floods as well as during periods of small or minimum flows ; the former in order to determine how large a channel should be pro- vided for removing the floods, and the latter in order to ascertain how much sewage may be discharged into the creek without foul- ing it to the point where it will become offensive and dangerous to health. In its present condition the channel is too small to remove the floods, while during dry weather the pollution of the water is so great as to make it a nuisance and a positive menace to the health of the residents of the city. After a personal reconnaissance of the watershed of the creek, I have, with the aid of the best data available, estimated the stream flow under different conditions to be as follows : 1 8 PROPOSED MUNICIPAL IMPROVEMENTS. At the south line of the city: area of water shed, 33.9 square miles ; flood flow, 1,073 cubic feet per second; minimum flow, 3.8 cubic feet per second ; ordinary low water flow, 11 cubic feet per second. At the bend s miles north of State street: area of water shed, 16.4 square miles; flood flow, 863 cubic feet per second; minimum flow, 1.7 cubic feet per second ; ordinary low water flow, 7 cubic feet per second. A flowing stream whose waters are not used for domestic pur- poses may stand a certain amount of pollution without becoming offensive. The permissible amount of pollution will depend upon the quantity of water flowing in the stream, and the character of its channel, as well as upon the amount and kind of polluting matter already in the water. When caused by sewage it is more conven- ient and rational to express the amount of pollution in units of population rather than in actual quantities of polluting matter. The average amount of solid matter contributed per person per day is quite constant, while the quantity of water forming the liquid part of sewage varies greatly in different cities, ranging from about 30 to over 200 gallons per capita per diem. In general terms it may be stated that a flowing stream free from pools, with its bed covered with water and its banks smooth enough not to catch floating matters, may receive for each cubic foot of water flowing through it per second the sewage of from 200 to 330 people without creating a nuisance. When it receives the sewage of only about 150 people to each cubic foot or flow per sec- ond it is certain that no nuisance will result ; when it receives the sewage of 500 or more people, for each cubic foot of flow per sec- ond, a nuisance will surely follow. This gives us a measure of the extent to which Paxton Creek may safely serve as an open sewer. By reference to the table on page 19 it will be found that the minimum flow of the stream at the south line of the city is about 2.8 cubic feet per second. At such times it could receive properly the sewage of about 1,000 people, but would be polluted to oflfen- siveness by the sewage of about 1,500 people. At the time of ordinary low-water flow we find that the stream might, under proper conditions, receive the sewage of about 3,500 persons, but that it would certainly become ofifensive when receiv- ing the sewage of 4,500 people. The following table shows that at the present time the sewage of about one-third of the popula- tion of the city finds its way into the creek, as follows : SBWAGE OVeRI,OADING. 19 Estimated Population Ward Population, 1900 Census Using Sewers I3t 3909 1800 2nd 4269 3000 7th 7200 6000 8th 4400 3500 9th 6455 5100 loth 1906 600 20000 From the foregoing it is seen that the stream now carries over five times as much sewage as could be safely discharged into it at ordinary summer stages, and twenty times as much as would make it offensive during a very dry season. The correctness of these data is attested by the fact that at State street, on August ist, 1901, with a flow of about 15 cubic feet per second, the creek was decidedly offensive with the sewage of 6,600 people, or a little over 400 people per cubic foot of stream flow per second. It is evident, therefore, that it would be improper to permanently continue to use the creek for the reception of the sewage of more than from 2,000 to 3,000 people, were it to be maintained as an open channel. Further, as the population residing in the districts draining into the creek is now nearly 24,000, and will in the future probably reach 50,000, it is clearly evident that its use as an open sewer must be prohibited. To flush it out with water from the city mains would be impracticable by reason of the great distance such flushing would have to extend, and the great quantity of water which would be necessary to create sufficient velocity of flow in the channel to carry along the suspended matter. Hose streams applied at points where decomposing matters had accumulated would undoubtedly disperse them, but unless the flow in the channel were sufficiently rapid and deep to carry the loosened matters along to the mouth of the creek, deposits would form again a short distance below. To sup- ply a sufficient quantity of water to carry out the deposits at the ordinary summer stage of the stream would require a pumping plant capable of supplying six times the amount of water now con- sumed by the city for all purposes. The floods in the creek must be studied in connection with the fluctuation of the level of the water surface of the Susquehanna River, as high water in the river affects the water surface in the creek, and thus the carrying capacity of the stream. 20 PROPOSED MUNICIPAI< IMPROVEMENTS. A diagram on Plate XV shows the rise and fall of the river at the pumping station of the water works for every day of the year from 1895 to 1900, inclusive. The diagram was prepared from data published in the Annual Reports of the Water Department. The elevation of the low-water mark of 1803, as determined by Mr. M. B. Cowden, City Engineer, is 289.31 feet above sea level. The table below on this page, prepared from this diagram, shows the number of days each year that points at dififerent elevations at the pumping station were submerged below the river surface. Elevations of Points above Sea Level, in feet. 290 291 292 293 294 295 296 397 299 300 301 302 303 304 Days of Submergence. 1895 . 1896 . 1897 . 1898 . 1899 . 1900 . Aver- ages 252 184 111 89 50 33 17 9 5 3 2 1 331 257 185 112 69 45 33 33 16 9 7 5 3 3 323 216 175 106 73 51 31 14 7 3 1 341 300 321 151 97 66 40 34 13 6 3 3 3 1 267 309 153 103 73 55 39 16 5 3 3 3 268 203 139 97 81 46 27 13 10 8 4 3 297 233 164 109 74 48 33 16 9 6 3 3 1 H It is seen by reference to the diagram that the conditions of flow are quite similar from year to year, the general characteristics be- ing a moderately high stage of water during January, February and March, the highest point being reached in March or April; then follows a gradual decline through the summer months, the mini- mum stage being reached in September. After this follows a rise with occasional short rapid floods until the winter stage is reached. Occasionally very high floods come down the river, caused by ex- cessive rains in the upper valley, and these rise to much greater heights than the average or usual winter or spring floods. Placed in the order of their occurrence the recorded heights of the river at the pumping station during the great floods were as follows : 1846 311-55 feet above sea level. 1865 314.30 " " " " 1886 310.64 " " " 1889 316.47 " " " 1894 3I4-97 " " " " FLOODING OF THE VALLEY. 21 The frequency of these floods follow no general law. Thus, be- tween the first floods a period of 19 years elapsed; between the second and third, 21 years; between the third and fourth only three years, and between the fourth and last, five years. The average slope of the water surface of the Susquehanna at Harrisburg, at moderate flow, is about 2 feet per mile, and dur- ing the floods probably about the same when the flood is at its greatest height, while it is greater when the river is rising. At the mouth of Paxton Creek, therefore, the flood heights might be expected to be two feet lower than at the water house. Floods reaching a height of 312 feet above sea level at the water house would, therefore, flood back through Paxton Creek, and submerge perhaps the greater part of the flat land up to the north line of the city. River floods reaching elevation 309 at the water house would cause water to flow back into the Paxton Creek channel and out of its banks and over the flats in several places, while floods lower than this would cause little damage, their effect being felt only in case Paxton Creek were in flood condition at the same time. By reference to the table on page 20 it will be seen that eleva- tion 303 has been submerged, on the average, at the pump house only about one day every other year, while elevation 302 has been submerged on the average one, elevation 301, two days, and eleva- tion 300, three days per year. Taking lower elevations, it will be seen that at 296, a point would be submerged about one month a year ; 294, two and one-half months, and 292, nearly half the year. That is, since the beginning of 1895, the river level has not been high enough to overflow the banks of Paxton Creek and flood the flat lands. Evidently, therefore, the floods of the valley are of two kinds, those caused by the Susquehanna River and those caused by Paxton Creek. There are two methods of preventing the flooding of the lower Paxton Creek Valley by backwater from the Susquehanna. The first would be to build dykes along the banks of Paxton Creek from the bend three miles north of State street to the mouth of the creek, carrying one dyke north along the bank of the river as far as Washington street, and the other south along the river to the line of Cedar street, and thence east to Cameron street, thus clos- ing out the river water but permitting Paxton Creek to discharge through its natural channel. For this method to be effective the dyke would have to be tarried across the Pennsylvania Canal, clos- ing the canal channel. At the same time it would be necessary to 22 PROPOSED MUNICIPAI, IMPROVI>lENTS. divert the surface waters from the hills into channels cut along the foot of the bluff. These channels should be high enough to be above the greatest flood level in the valley, and should discharge part of the surface water into Paxton Creek, at the bend, and part into Spring Creek at the south line of the city. A sewer would also have to be provided along the creek for the purpose of intercepting all the house sewage and storm water from the streets in the area draining to the creek, and a pumping plant would have to be pro- vided so that the sewage could be pumped away when the river was too high to permit a gravity discharge. This would occur on the average probably only once in ten years, and the pumps would have to run then only about two days. The cost of building these works would probably reach about $800,000, and the annual cost, to be met each year, including interest on first cost, de- preciation of the works, the cost of pumping the sewage two days every ten years, and the cost of keeping the creek channel in order, would be about $29,000 per year. On account of its great cost, therefore, I have ruled out this project. Another way to prevent back-flooding would be to cut a new channel for Paxton Creek, leading it into the Susquehanna through Fox Run, about 4 miles north of the city, throw a dyke along the river bank from Washington street to the line of Cedar street, and the'nce to South Cameron street, diverting the water from the hills on the east side of the valley into Paxton Creek at the bend and into Spring Creek at the south line of the city, and intercepting the sewage as in the previous method. This would cost about $540,000 and the annual expense would be about $21,000. Such a method would be a very good solution of the problem, and is not impossible of execution. In the following discussion it must be borne in mind that the works described are not designed to prevent the flooding of the valley if the surface of the Susquehanna River should be up to 305 at the mouth of Paxton Creek at the time the Creek was in its maximum flood — such a coincidence of floods would throw the creek out of its banks and flood the valley. The probability of such an occurrence, however, is very remote, because the floods from Paxton Creek rise very rapidly after a heavy rain, while floods in the Susquehanna are caused by storms of smaller intensity of rate but covering a greater extent of country. Storms and conditions that cause great floods in the river do not cause heavy floods in Paxton Creek, while storms causing the great floods in Paxton PROTECTION FROM FI/OODS. 23 Creek would not appreciably affect the flow in the Susquehanna River. I feel safe after considerable research in stating that each of the plans hereinafter discussed would be satisfactory hygienically, and would afford protection from all floods except those caused by backwater from the Susquehanna River. The choice of methods will depend therefore on the cost of the works considered also in the light of the cost of the yearly operation and maintenance. There are four general plans on which the works for the protec- tion against floods from Paxton Creek may be designed. These are, (i) the provision of a channel of suitable cross-section and slope; (2) the diversion of the floods into Fox Run; a suitable channel and accessory works being provided therefor ; (3) the re- tention of the floods in the upper valley of the creek by means of dams proportioned so as to catch the flood waters; and (4) com- binations of the above methods. The cross-sections on which the estimates of cost of the works are based were calculated by the use of Kutter's formula, using for the value of "n" the figures .030 to .035 for the sections in earth, and .015 for the concrete sections. Slightly lower coefficients would suffice if the channels were kept free from deposits, growths of vegetation, etc., but as such maintenance could probably not be obtained, I have not used the lower coefficients, in order that my estimates may be safe. The cross-sections of the various channels in earth have been proportioned so that during floods the velocity would not be so great as to scour out the bottoms, while during ordinary summer flow the velocity would be sufficient to prevent deposits. On Plate IV will be found a profile of the creek showing the present bottom and the slopes of the water surface on August i8th, 1891, as determined by Mr. J. E. Whiteside, on October i8th, 1891, as determined by the City Engineer, and on August 19th, 1901, as determined by my survey. A comparison of these lines shows that the tendency of the creek to silt up its bottom is very slight. The only points where deposits of any considerable amount have oc- curred are below the mouths of the large sewers coming from the hill on the east side of the valley, the creek bringing comparatively little silt down to the portion of its channel lying below the north line of the city. This fact gives me considerable confidence that such improvements as would be made would remain in good con- 24 PROPOSED MUNICIPAL IMPROVEMENTS. dition, if proper means were used to intercept the silt from the sewers. Before discussing the various means of preventing the floods in Paxton Creek valley, it would be well to determine approximately what expenditures are warranted for accomplishing this purpose. The great river floods occur at infrequent intervals, averaging per- haps ten years apart. It is very difficult to estimate the damage done by these floods in money values, but if we assume provisional- ly that the damage doile by a single flood might reach $100,000, in- cluding the damage to private property, the cost of cleaning up after the flood, and the repairing of streets, bridges, houses, etc., an expenditure of about $10,000 per year on the part of the .city to secure protection would be warrantable. As stated on page 19, one feature which must be a part of any scheme for protection is to provide for keeping the city sewage out of the creek, in order to protect the general health of the com- munity ; therefore, the cost of this part of the work should not be a charge against protection from floods. As, however, the work for protecting the valley from floods must be done at the same time as the work for preventing the fouling of the creek, the costs of the two works are given together in the estimates which follow, and, therefore, in order to make comparisons between the esti- mates and the allowable yearly expenditure for protection works, the annual cost of the nuisance-prevention works should be added to the sum above mentioned. This cost, including interest, depre- ciation, and operation and maintenance would average about $5,000 per year, and, therefore, if we add $5,000 to the $10,000 above men- tioned for guarding against floods, we arrive, provisionally, at the sum of $15,000 as the allowable yearly expenditure for protective works. One point, however, that should not be lost sight of in the con- sideration of this question is that the land in this valley, if pro- tected from floods, would increase in value, but such an increase would benefit directly only the holders of the property in the val- ley. This increased valuation would permit higher assessments for taxation, and therefore an extension of the limit to which the city could bond itself for needed public works. How far this con- sideration should affect the amount of indebtedness the city ought to incur for protecting this property is a question for others to de- cide. I take it that when a destructive flood, one that inflicts great damage upon individuals who pay taxes, visits the valley, the PAXTON CREEK IMPROVEMENT. 25 -whole city, for the sake of the general public health, should lend a hand and pay the greater part of the expense incurred in cleaning up the debris, and that it should repair the roads, bridges, and even private property, when necessary, when the dam- age done would cripple that part of the community financially. It will be necessary to consider the question carefully in order to determine whether it is practicable to prevent the floods, what methods must be used, what such protection would cost, and whether this cost would be so great as to render protection inad- visable. In deciding what cross section and slope to give the stream it is necessary to consider both concrete lined channels and channels excavated in the natural soil, because the rapidity of flow of the water in the channel depends, other things being equal, upon the nature of the surfaces along which the water glides. If the channel is smooth the stream may have a smaller cross-section and a flatter slope than if it were rough. This fact influences cost, and in order to determine the relative advantages of the various combinations possible, I have worked out in detail twenty-four plans for treating the creek. These may be grouped into four general classes, as follows : 1. The treatment of the present creek channel after taking out the city sewage. 2. The treatment of the present creek channel in connection with a dam on Paxton Creek to hold back some of the flood water, and the interception of the city sewage. 3. The diversion of the floods into Fox Run, with the intercep- tion of the city sewage. 4. The holding back of part of the floods by a dam on Paxton Creek, and the diversion of the rest of the flood water through Fox Run into the river. Under each of the above heads there are three methods of tak- ing care of the sewage and storm water of the city. These are as follows : 1st. A small intercepting sewer, along the creek valley, would be provided for receiving only the house sewage, or dry-weather flow of the sewers. This sewer would be small in diameter and the slope necessary to give sufHcient velocity of flow to the sewage would bring the sewer out, at the point where it would reach the river, at an elevation too low to enable it to discharge by gravity. It would be necessary, therefore, to build a pumping station a little 26 PROPOSED MUNICIPAL IMPROVEMENTS. below Mulberry street, and raise the sewage to a sewer at higher level. During rains, this sewer would be too small to take the flow of the joining sewers, so that overflows would have to be provided to take the surplus to Paxton Creek. This would be perfectly proper, because at times of such overflows the discharge of the creek would be sufficient to dilute and carry away the sewage. 2d. An intercepting sewer would be built of large enough diam- eter to discharge the sewage and a little storm water mto the river without pumping, and provision would be made for overflows to the creek to act in time of heavy rains, as before. The sewer would be as small as the grade available would permit, yet in order to prevent deposits it would have to be large enough to discharge about 22 cubic feet of creek water per second when the flow of the stream would furnish this amount. This would require a sewer five feet in diameter, with overflows to the creek as above men- tioned. 3d. A sewer of large enough diameter to take all the sewage and storm water from the flat part of the valley would be con- structed. All the estimates have been based on running the sewer from the line of Schuylkill street to the river, following the west bank of the creek to State street, then running down Tenth street to the P. & R. railroad. Crossing under the latter it would follow the stream to Paxton street, just beyond which it would pass under the Pennsylvania canal and Pennsylvania R. R. tracks, to Tusca- rora street, and thence to the Susquehanna River. At the mouth of the sewer, a line of cast-iron pipe would lead out into deep water in the river 150 feet beyond the low-water line, in order to prevent the sewage from stranding on the shores. The open end of the sewer would terminate in a masonry wall at the river bank, with wing walls on each side. Flap gates would be placed over the end of the sewer to prevent the escape of the sewer air at that point, but yet permit the flood waters to pass out. On the upper end of the sewer a catch basin would be provided for the purpose of catching the silt and the stones. Inclined screens of ample size would be placed in the basins to prevent the entrance of floating matter. The cost of connecting the present and proposed new sewers with these intercepting sewers has been added in all cases, and the estimates represent the total cost of the various projects completed with all the necessary accessory works. In the estimates of cost ESTIMATES. 27 of the improvement of the stream ample allowances have been made for the cost of all the accessory works, including the under- pinning of the bridges, the walling up of the portion flowing through the built up section of the city, the replacing of the Hem- lock street bridge with one of longer span, the removal of the pier under the Market street bridge, and all other necessary work. The estimates cover the cost of the intercepting sewer and the improve- ment of the stream channel from its mouth to the north line of the city. At that point the new channel would be low enough to drain the marshes lying beyond. General plans showing the various projects are given on Plates I, II, III and IV. We pass now to the consideration of the costs of the various projects investigated. These estimates have been carefully made out in detail, but summaries only are here presented, as the com- plete estimates would occupy too much space to make their repro- duction permissible. The same index letter is used for each plan and its correspond- ing estimate. ESTIMATED COST OE THE WORKS NECESSARY EOR THE IMPROVEMENT OE PAXTON CREEK. I. Estimates A and B are for works for the prevention of floods from both the Susquehanna River and Paxton Creek. A. Diversion of Paxton Creek into Fox Run ; dyke along Susquehanna River front ; interception of surface water along foot of bluff on east side of valley, and sewer for intercepting house sewage. Cost of construction $539,000.00 Annual cost of maintenance, including interest, depreciation, repairs and operation 30,666.00 B. Improvement of present channel, with dykes along both banks and along the Susquehanna River front from Washington street to Cedar street ; inter- ception of surface water along foot of bluff on east side of valley, and inter- cepting sewer for house sewage. Cost of construction $787,600.00 Annual cost of maintenance, including interest, depreciation, repairs and operation 29,367.00 Note. — All estimates are based on the abandonment of the Pennsylvania Canal. If the canal is not abandoned there is no way of preventing floods from the Susquehanna River. 28 PROPOSED MUNICIPAI, IMPROVEMENTS. II. Estimates C to X, inclusive, are for works for the preven- tion of floods from Paxton Creek alone. In estimates C to H, inclusive, the stream is not to be diverted, but its present course is to be improved to permit it to discharge its maximum flood volume. C. Improvement of present channel of stream by enlarging its section and improving its slope ; construction of 5-foot intercepting sewer for house sewage, sewer to dis- chai^e by gravity into the Susquehanna at Tuscarora street. Cost of construction $249,700.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 10,450.00 D. Improvement of present channel of stream by enlargjing its section and im- proving its slope ; construction of large interceptor for house sewage and storm water from the city ; sewer to discharge into Susquehanna at Tus- carora street. Cost of construction $424,600.00 Annual cost of maintenance, including interest, depreciation, re- pairs and operation 16,585.00 E. Improvement of present channel of stream by enlarging its section and improving its slope ; construction of small intercepting sewer for house sew- age only, with pumping station ; sewer to discharge into Susquehanna River at Tuscarora street. Cost of construction $358,500.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 18,447.00 F. Improvement of present channel of stream by providing a concrete channel of proper section and slope; construction of 5-foot intercepting sewer for house sewage, discharging by gravity into Susquehanna at Tuscarora street. Cost of construction $490,600.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 18 661.00 G. Improvement of present channel of stream by providing a concrete chan- nel of proper section and slope, construction of large interceptor for house sewage and storm water from the city. Sewer to discharge into Susquehanna at Tuscarora street. . Cost of construction $669,680.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 24 953 qo ESTIMATES. 29 H. Improvement of present channel of stream by providing a concrete chan- nel of proper section and slope ; construction of small intercepting sewer for house sewage only, with pumping station. Sewer to discharge into Susque- hanna River at Tuscarora street. 4^ Cost of construction $457,800.00 Annual cost of maintenance, including interest, depreciation, operation and repairs ^ 26,825.00 In estimates I to N, inclusive, the stream is not to be diverted into Fox Run, but a dam is to be built across Paxton Creek to re- tain part of the floods, and its present channel is to be improved for the remainder. I. Dam to be built across Paxton Creek to retain part of floods ; present chan- nel to be improved by rectifying its section and increasing its slope ; five- foot intercepting sewer for house sewage, discharging by gravity into the Susquehanna at Tuscarora street. Cost of construction $245,300.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 10,295.00 J- Dam to be built across Paxton Creek to retain part of floods ; present chan- nel to be improved by rectifying its channel and improving its slope ; large interceptor for house sewage and storm water from the city, discharging by gravity. Cost of construction $429,000.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 16,329.00 K. Dam to be built across Paxton Creek to retain part of floods, present chan- nel to be improved ; small intercepting sewer for house sewage only, with pumping station. Cost of construction $254,100.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 18,443.00 L. Dam to be built across Paxton Creek to retain part of floods ; present chan- nel of creek to be improved by providing a concrete channel of proper section and slope; five-foot intercepting sewer for house sewage, discharging by gravity. Cost of construction $496,100.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 19,073.00 30 PROPOS:BD MUNICIPAI/ IMPROVEMENTS. M. Dam to be built across Paxton Creek to retain part of floods ; present chan- nel to be improved by providing concrete channel of proper section and slope ; large interceptor for house sewage and storm water from city, discharging by gravity. Cost of construction $671,000.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 24,509.00 N. Dam to be built across Paxton Creek to retain part of floods ; present chan- nel to be improved by providing concrete channel of proper section and slope ; small intercepting sewer for house sewage only, with pumping station. Cost of construction $504,900.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 27,031.00 In estimates O to S, inclusive, the entire flood flow of the stream is to be diverted into Fox Run, and a small channel is to be pro- vided for the creek, to take care of the drainage below the point of diversion. O. Stream to be diverted into Fox Run and present channel through the city to be rectified by improving its section and slope ; five-foot intercepting sewer to carry off house sewage, discharging by gravity. Cost of construction ... . ... $303,050.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 12,917.00 P. Stream to be diverted into Fox Run and present channel to be rectified by increasing slope and improving section ; small sewer for house sewage only, with pumping station. Cost of construction . . .$311,850.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 20 717 00 Q- stream to be diverted into Fox Run and channel to be improved by pro- viding a concrete channel of proper section and slope ; five-foot sewer for house sewage only, dischargfing by gravity. Cost of construction $535,930.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 30 qi^ij qq R. Stream to be diverted into Fox Run, and present channel to be improved by providing a concrete channel of proper section and slope; small sewer for house sewage only, with pumping station. ESTIMATIJS. 31 Cost of construction $543,950.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 28,638.00 S. Stream to be diverted into Fox Run and drainage of territory below point of diversion to be taken into a large intercepting sewer discharging by gravity, thus doing away with the open channel through the city. Cost of construction $398,750.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 15,280.00 In estimates T to X, inclusive, a dam is to be built on upper Pax- ton Creek to retain part of the floods, and the flood waters below the dam are to be diverted into Fox Run; a small channel to be provided through the city to take care of the drainage of the ter- ritory below the point of diversion. T. Stream to be diverted as above, and present channel to be rectified by im- proving its section and increasing its slope ; five-foot sewer for house drain- age, discharging by gravity. Cost of construction $266,640.00 ' Annual cost of maintenance, including interest, depreciation, operation and repairs 11,342.00 U. Stream to be diverted as above, and present channel to be improved by rectifying section and increasing slope ; small sewer for house drainage, with pumping station. Cost of construction $275,000.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 19,935.00 V. Stream to be diverted as above, and present channel to be improved by providing a concrete channel of proper section and slope ; five-foot sewer for house sewage, discharging by gravity. Cost of construction $498,740.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 19,266.00 W. Stream to be diverted as above ; present channel to be improved by pro- viding a concrete channel of proper section and slope ; small intercepting sewer for house drainage, with pumping station. Cost of construction $508,310.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 27,491.00 32 PROPOSED MUNICIPAL IMPROVEMENTS. Stream to be diverted as above ; drainage of territory below point of diver- sion to be taken into a large intercepting sewer discharging by gravity, thus doing away with an open channel through the city. Cost of construction $363,840.00 Annual cost of maintenance, including interest, depreciation, operation and repairs 13,906.00 For convenience in making comparisons between the above es- timates they are rearranged in the following table. C D E F G H For Prevention of Floods from the Susquehanna River and Pazton Creek. Plan. Cost of con- struction. Cost of operation. Character of proposed channel of creek. Kind of intercept- ing sewer. A . . B . . $539,000 787,600 $20,666 29,367 Natural Natural, 5-foot. 5-foot. For Prevention of Floods from Paxton Creek alone. Creek to be Maintained ia Present ChanneL •$249,700 424,600 258,500 490,600 669,680 457,800 $10,450 16,585 18,447 18,661 34,968 36,825 Natural, . Natural, Natural, . Concrete, Concrete, Concrete, 5-foot. Large. Small. 5-foot. Large. Small. Storage of part of floods in Upper Valley and Improvement of Present Channel. I . . $245,300 $10,295 Natural 5-foot. T • . 429,000 16,329 Natural Large. K . . 354,100 18,443 Natural Small. L . . 496,100 19,073 Concrete 5-foot. M . . 671,000 24,509 Concrete Large. N . . 504,900 27,021 Concrete Small. Floods to be Diverted into Fox Run. O . . P . . s ; ; $303,050 311,850 535,920 543,950 398,750 $12,917 20,717 20,677 28,638 15,280 Natural, Natural, Concrete Concrete, ...... 5-foot. Small. 5-foot. Small. Large. HARRISeUflG LCAOUL TOR PUBLIC IMPROVCMCNTS IMPROVEMENT OF PAXTON CREEK VALLEY Scale of Feet PLATE I JAMES HFUERTES CiViL AND SaNITARV EHCrHEQt SCPTtMStR (SOt PLANSC.F.DAND6 HARRlSeuKG LCAGUC FOR PUBLIC IMPROVCMCNTS IMPROVEMENT OF PAXTON CREEK VALLEY PLATE IV PLANS T.VANDX li ■- 10 ^ — s- 1 3< £ — ■ 5 ■ ^ — i »^, — Ortlmary High N 1 ^S y m 5 = ^ m *^ ^ iiiii r^ water m L^Bm 1 yUUjjjyg ^ " ^m\, mAilii = "■ ' -^ " LOW water f IBOJ ^ 1 1 ( » 00 zo 00 30 00 40 00 » 00 60 00 7ft BO BOOO 9000 KWOO IIDOO IZOOO 13600 HOOO 0istancf5inf«t '*5epr6p6seil' CROSS SECTION OF PAXTON CREEK Scale of Feel PROFILE OF INTERCEPTING SEWER ] noo Distances infeei JAMES HFUERTES -Civil and Sanitadv En6ineui StFTCMBER I90r COMPARISON OP COST. Combined Storage in Upper Valley and Diversion into Fox Run. 35 T . . $366,640 $11,343 Natural, 5-foot. V . . 275,000 19,935 Natural Small. V . . 498,740 19,366 Concrete 5-foot. w . 508,310 27,491 Concrete Small. X . . 363,340 13,906 Large. As stated on page 24, the choice of methods will depend upon the cost of the works and the cost of maintaining them. We can at once, therefore, rule out certain of these projects, and narrow the discussion down to two or three. Thus, on looking over the list it will be found that the schemes requiring the pumping of the sew- age, whether an earth or concrete channel should be adopted for the creek, (that is, estimates E, H, K, N, P, R, U, and W,) while slightly less expensive in some cases than the others of the same class as far as cost of construction is concerned, are all about $9,000 per year higher in cost of operation ; this is due to the cost of pumping and to the greater allowances for depreciation and' repairs. Therefore all the estimates in which the interceptor with, the pumping station enters may be ruled out at once. Next it will be seen that for the projects in which the 5-foot interceptor enters, i. e., C, F, I, L, O, Q, T and V, the estimates are all lower than for the projects containing the large interceptor, i. e., D, G, J and M ; therefore, these may be ruled out. Estimates S' and X, in which the large interceptor enters will be discussed later on. Estimate B for the protection against floods from the Susque- hanna is larger than A, and less favorable in many ways. We see, therefore, that choice must be made among A, C, F, I, L, O, Q, S, T, V and X. Considering now only the estimates contemplating the protec- tion from floods in Paxton Creek, we find, by comparing estimates C and I with O and T, and F and L with Q and V, that the esti- mates in which the diversion of floods into Fox Run is contemplat- ed, are all higher than those providing for the retention of the pres- ent channel of the stream. Therefore estimates O, Q, T and V are ruled out, leaving for further consideration A, C, F, I, L, S and X. Leaving out A, S and X, for the present the choice would be among C, F, I and L. Comparing now C and I we see that in C it is contemplated to provide for the whole flow of the creek in a new earth channel 3 ^4 propos:h;d municipai, improvements. through the town, while in I it is proposed to build a dam on Pax- ton Creek, and provide for the rest of the flow in a new earth chan- nel through the city. Between these two I should decide in favor of C, because although the first cost is a little higher than that of I, the works would offer no complications in carrying them out, while in I considerable delay might be entailed in securing the land necessary for the reservoir and in the construction of the dam. Further, the adoption of this plan would be dependent on the use of the impounded water in the reservoir to supplement the present city water supply, as detailed on page 82. For similar rea- sons, I should give the preference to F over L,, and S over X ; and we have for further discussion A, C, F and S. The difference between C and F is that in F the creek channel through the city is to be lined with concrete, while in C it is to be merely improved by trimming out the sides and bottom to secure a proper section and slope to discharge the maximum floods. Either project would be satisfactory in all particulars, and there is no reason for prefering the masonry channel. F, therefore, goes out, leaving A, C and S. Project A, at a cost of $539,000, offers complete protection against all floods, and is the ideal method. Project C, at a cost of $249,700, offers protection against all floods except those from the Susquehanna River, which occur, per- haps, every ten years, on the average. Project S, at a cost of $398,750, offers the same protection as C, but has the advantage that the creek channel through the city is permanently obliterated. To compare C with S we must estimate the value of the benefits to be derived by closing up the creek channel through the city. The only advantage would be the opening up for settlement of the strip of land through the city, now occupied by the creek. This would add about 20 acres to the available land in the valley. The differ- ence between C and S, as to cost, is about $149,000; the increased area should be worth, on the average, about $7,450 per acre. The cost for complete protection from floods from both Pax- ton Creek and the Susquehanna River would be, including interest, depreciation, maintenance and operation of works, a little over $10,000 per year more than for protection against floods from Pax- ton Creek alone. While there is no question but that this project has many advantages, its great cost would stand as a bar to its adoption. Should there be longer periods of time between the FINAL RECOMMENDATION. 35 .great Susquehanna floods, say 20 years or more, the advisability of carrying out this project would be very questionable. There is, as a matter of fact, as much likelihood that it might be 20 years as 10 years, 5 years or one year, before the occurrence of another great flood. No general law governs the frequency of these catastro- phes. They come when conditions are favorable, and these condi- tions are so complex and inter-related that prediction of their si- multaneous occurrence carries one into the realm of guesswork. I feel therefore, that were I a property holder in the valley I would rather take the chances ofifered by the uncertainty in the fre- quency of the floods from the Susquehanna than the certainty of being taxed every year for protection which might not be needed oftener than once in twenty years. In consideration of all the foregoing data, therefore, I recom- mend that Paxton Creek be retained in its present channel, as an open stream, that its section be enlarged, its bed deepened, its slope steepened, and that the dry-weather flow of sewage now go- ing into the creek be diverted into an intercepting sewer, 5 feet in diameter, reaching from Schuylkill street to the Susquehanna Riv- er at Tuscarora street. The general plan showing the sizes, slopes and elevations of the channel and sewer, and profiles of each, will be found on Plates I and IV. The estimated cost of the work for improving the sanitary condi- tion of and the prevention of floods in Paxton Creek is given more in detail, for the plan recommended, as follows : Improvement of Channel from Schuylkill Street to the Mouth of the Creek. Excavation $57,000.00 Walling sides and paving bottom, where necessary, from State street to Market street 15,500.00 Protecting bottom of creek and abutments of R. R. bridges, crossings, etc 3,700.00 New bridges at Hemlock and Mulberry streets and changes at Paxton street 13,000.00 Improvements at Market street crossing 6,000.00 Lowering State street water mains and incidentals. . . 2,000.00 $96,200.00 Intercepting Sewer. Excavation and refilling $28,000.00 Concrete and expanded metal work 49,000.00 Manholes 800.00 Outfall works 2,000.00 Settling basins at Schuylkill street 1,000.00 Amount forward $80,800.00 36 PROPOSED MUNICIPAI< IMPROVEMENTS. Amount brought forward $80,800.00 Connecting existing and proposed sewers, including overflows, 40,000.00 Extra work crossing tinder R. R. track and incidentals, 10, 000. 00 130, 800. GO $327,000.00 Ten per cent. , 33,700.00 Total $349,700.00 Annual Cost of Operation and Maintainance. Interest on $349,700 at 3i^ per cent $8,739.50 Depreciation of perishable parts of works, 60. 50 Ordinary repairs and supplies, 600.00 Labor for superintendence and cleaning 1,050.00 $10,450.00 THE IMPROVEMENT OF THE WATER SUPPLY OF HARRISBURG, PENNA. The water supply of Harrisburg is derived from the Susque- hanna River. The pumping station is located on the bank of the river at the foot of North street, and the water is brought to the pump well through two lines of 30-inch cast-iron pipe, extending out into the river 610 and 704 feet, respectively, and terminating in cages or screening boxes. The pumps force the water through a line of 30-inch pipe to the distribution reservoir at Reservoir Park. The reservoir is 270 ft. wide, 520 ft. long and holds, when the water is 25 ft. deep, 20 milHon gallons. The elevation of the water surface when standing 26 ft. deep in the reservoir is 500.2 ft. above sea level. The elevation of the floor of the pump room is 305.06 ft., of the cyhnders of the pumps about 308 and of the bot- tom of the suction well 280.7 ^eet, above sea level. At the pump- ing station, and connected with the force main, is a stand pipe the top of which is 220.5 f^ct above the centre of the pump cylinders. The pumps together have a daily rated capacity of 10,205,000 gallons per twenty-four hours. As the water consumption aver- ages now nearly 8,000,000 gallons per day, it is readily seen that there is no reserve capacity in case of an accident to either pump. To remedy this, a new high-duty pump has been pur- chased, and preparations are now being made for its installation. The intake pipes terminate in a deep part of the river, well chosen to secure good water. The average daily consumption of water from 1888 to 1898, in- IMPROVEMENT OE WATER SUPPLY. 37 •elusive, is shown on Plate XV. On this plate is another diagram showing the average daily per capita water consumption for the same years based on the total consumption and the population as given by the "growth-of-population" curve. The data for these -diagrams were taken from the Department reports. By inspection it will be seen that the consumption is, while high, lower than in many cities of similar size and characteristics. This is no doubt due to the excellent meter system in use. Had not this system been introduced some years ago, the consumption at this time would probably have been double the present amount, and would have nearly doubled the expenses of the pumping station. In designing works for water filtration it is not necessary to look very far into the future, except to be sure that a sufiSciently large tract of land may be secured for future extensions of the works. On the account of the possibility of building additional filters when required it is sufficient to provide filtering capacity for the needs of the city for a few years following the time of the com- pletion of the works. I have assumed that the provision of lo million gallons daily would be a sufficient quantity to allow for in making the designs on which the estimates of cost are based. At the present rate of increase of population, and with a daily per capita supply of 135 gallons, this would be sufficient for a popula- tion of 75,000 people. It is probable, however, that the rate of consumption will increase somewhat with the development of manufacturing industries to larger proportions, and with the .greater needs and greater wastes characteristic of larger cities ; and I should regard the provision of 10 million gallons daily as suffi- cient to meet the city's needs for from ten to twelve years. A population of 75,000 will probably not be reached before 1912, pos- sibly not before 1920. I think before these dates are reached ex- tensions might be advisable. As regards the pollution of the Susquehanna by sewage and surface washings, under the present conditions I think we may safely eliminate the Harrisburg sewage from consideration so far as the water supply is concerned. I have watched the river front carefully during low water stages, when heavy local rains were taxing the sewers severely, to see whether the •discoloration of the river due to surface water extended out dangerously near the intake of the water works. This would be a pretty safe indication as to whether the sewage from the sewers 38 PROPOSED MUNICIPAL IMPROVEMENTS. above the water works was a source of danger, because at such, times the river presents a very characteristic appearance. We find nearest the shore and extending out two or three hundred feet the- dark brown water from the sewers ; immediately beyond this is a stream of clear, bright Susquehanna River water, and still beyond, this, for the remainder of the width of the river, the yellow water of the Canodog^inet Creek and Juniata River. At low water the velocity of the river is least, and during local heavy showers the force of discharge from the sewers greatest, so that at such times- the discoloration from the sewers would extend out farthest from the shores. From my observations I could not see that there would be the slightest danger of contamination from the Harris- burg sewers. Possibly after a flood and with a falling river the sewage from far up the stream might be carried out to the intakes,,, but it would be so greatly diluted, and these conditions would prevail so short a time, that they could hardly be called a menace to the public health. I have made no chemical or bacteriological examinations of the water, because there are conditions under- which such analyses would be difficult to interpret. The exercise of considerate judgment will demonstrate sufficiently well the- points I wish to bring out. The Susquehanna River, with the exception of the Saint Law- rence, is the largest stream emptying into the Atlantic Ocean on the Eastern coast of North America. Its watershed above Harris- burg is upward of 23,400 square miles. Its bed, however, is too steep to permit of continuous navigation. Just above the head of" Chesapeake Bay there is a fall of about 80 feet in a distance of ten miles, and hence the velocity of the water is entirely too rapid to permit of the use of the stream for transportation purposes. This circumstance has been a principal factor in tending to preserve the purity of the water, because such a waterway, reaching as it does from the ocean into a country rich in mining products, would probably, if navigable, have been lined with cities during the days of water transportation, and its condition as to pollution would have been far worse than it now is. The total population on the watershed above Harf isburg is now over two million people, 554,000 of which reside in the cities and towns immediately upon the banks of the river or its tributaries ; of these, 500,000 live in cities or towns the sewage of which is dis- charged into the river in a crude state. These cities are as follows :, POLLUTION. 39 Name of City. Population U. S. Census of 1900. Kind of Sewerage System. Distance by water above Harrisburg,. Miles. Binghamton, Elmira Sayre Clearfield, . . . Owego ■Philipsburg, . . Emporium, . . Wyalusing, . . Meshoppen, . . *Altoona, . . Carbondale, . Dunmore, . . . Scranton, . . . Pittston, . . . fBerwick, . . Williamsport, fHuntingdon, Wilkesbarre, . fNanticoke, Mt. Carmel, . fBloomsburg, . Shamokin, . . ■ Lewistown, . • Mifflintown, . 39,647 35,673 5,243 5,081 5,039 3,366 3,463 525 609 38,973 13,536 12.583 203,026 12,556 3,916 38,757 6,053 51,731 13,116 13,179 6,170 18,303 4,451 953 Combined Combined Partial Sanitary Partial Combined, Sanitary and Storm, . . Sanitary Sanitary and Storm, . . Partial Storm Purification Works, . . . Sanitary and Storm, . . Partial Combined (No data) Partial Storm, Sanitary and Storm, . . Has sewers Combined, Sanitary and Storm, . . Partial Has sewers, Combined Some Private Sewers, . . Private sewers, 210 300 190 190 185 185 175' 160- 145. 185 120- 110- 105- 96- 93 90 90 90 83 75 70 65 52 42 532,739 It is seen from the foregoing table that there is undoubtedly considerable pollution. At extreme low water this pollution would be measured by a flow of 4.6 cubic feet per second to each 1,000 persons. By reference to the table on page 67 it will be seen that there could never be any visible signs of sewage in the river when it reaches Harrisburg. The average velocity of flow in the river at low-water stages is probably not less than one foot per second between Harrisburg and Binghamton, from which it may be seen that sewage from the latter place would reach Harrisburg in about 12 days. During heavy freshets the time would probably not exceed two days. Be- ing in low stages a comparatively clear stream for a great part of the distance, and being well saturated with oxygen and nitrogenous food matter, the facilities for the transportation of pathogenic * Two-thirds of city's sewage not purified. f Sewerage data from Manual of American Water Works. 40 PROPOSED MUNICIPAIv IMPROVEMENTS. bacteria to considerable distances are better than in such streams as the Ohio and Mississippi Rivers, where the silt and clay in quiet stretches act as precipitating agents to carry the bacteria to the bottom where they probably cease to exist from lack of food sup- ply or other necessary life conditions. That there is a disappear- ance of pollution in such streams is pretty well established, while in the Mohawk the pollution can be traced for many miles by the typhoid fever epidemics down the river; one notable case being the transmission of an epidemic from Rome to Albany, a distance of 125 miles, all the cities between, which took their water supply from the" river, being visited one after another by the epidemic, with increasing violence, in about the time necessary for the disease to be incubated and transported from one city to the next. Bac- terial and chemical analyses in this case gave no conclusive data, but the death rates in the cities affected, in consideration of at- tendant circumstances, established the facts very positively. Certain influences tend to reduce the danger from using streams which have been polluted by sewage and surface washings from tilled fields and city streets. These are, the existence of long stretches of deep water in the river bed, pools formed by dams, the destruction of the food supply of the bacteria, the destruction of the bacteria themselves by certain forms of acquatic plant and low animal life, and the dispersion through an ever-increasing volume of water as the river flows toward the ocean. Since the bacillus of typhoid fever is very hardy, having been known to retain its virility for over 90 days in a cake of ice, it is not impossible for it to be carried from the source to the mouth of a river as long as the Mississippi, if it should find proper conditions for its nourish- ment. The troublesome question in any particular case is to ascer- tain whether or not these conditions are more likely to favor its life than its death. This question at the present day must be answered with great reserve, judgment being formed in any par- ticular case by comparison with other streams of a similar nature where observations have been made. For my part, I am inclined to believe that at low-water flow and at high-water flow the Sus- quehanna River water, so far as sewage pollution is concerned, is as good as the average surface waters of this country. At a moderate stage, say from three to five or six feet, I should be inclined to think that there would be considerable danger of the propagation of typhoid through the water, particularly in the early Fall, when the river makes its first rise after the summer season. TYPHOID POSSIBIL,lTl]JS. 4I It would be as unreasonable to state that the water is unfit to drink at any season as to say that it is perfectly safe at all times. It should be classed between these extremes, part of the time safe and the other part unsafe. I am aware that I am upon risky ground in making insinuations concerning the quality of a water so clear, bright and sparkling as that of the Susquehanna at Har- risburg for a considerable part of the year, but it must be remem-' bered that clearness is only one qualification of good water. In large cities using impounded surface waters, such as New York, Brooklyn, Boston and Baltimore, the average annual ty- phoid fever death rate is about 30 per 100,000 of population. In those using polluted supplies, like Pittsburgh, Cincinnati, and Philadelphia, it may run up to 300 and over. In cities using pure supplies from large springs or ground water from great depths, like Vienna, Munich and Dresden, the typhoid fever death rate averages below 5 per 100,000 of population ; in those using pure filtered supplies it eventually gets down to an average of six, in most cases. I have been unable to obtain satisfactory health records extending over a long period of time for the City of Har- risburg. I should expect to find considerable variation from year to year in the typhoid fever death rate — some years being as low as 30, or perhaps even less, and others where the figures would reach 100, or more, per 100,000 people. That is, as the population is about 50,000, I should expect to find from 15 or less to over 50 deaths per year from typhoid fever. This is corroborated by the records of typhoid fever deaths published by the Sanitary Depart- ment for the fiscal years 1898, 1899 and 1900. We find the total deaths for these years, from typhoid, to be 14, 18 and 23 re- spectively, or, roughly, 28, 36 and 46 per 100,000 of population. I have gone into this question with some fullness because informa- tion of this character is not as yet so widely disseminated in this •country as it should be. That bacteria may be carried down a stream for great distances there is no denying. It is a familiar fact, to all residents of this city, that the culm particles, which are very much heavier and larger than the bacilli, are brought down hundreds of miles; if these can be transported by the current there is no reason why the bacteria should not be brought down also. It is equally evident that they may be brought down in a living condition, as the time necessary for traversing the distance from Binghampton to Har- risburg may vary from about two days to two weeks. 42 PROPOSED MUNICIPAL, IMPROVEMENTS. Of course, on account of the great width of the river, the rela- tively small amount of water taken out at the intakes is insignifi- cant in comparison with the flow of the stream, and the number of bacteria which would be drawn into the pipes would be equally insignificant as compared with the number in the river. The Susquehanna River water is of a peculiarly mixed character. The Canodoguinet Creek empties into the river about opposite Maclay street, while on the same side, and about 14 miles fur- ther up stream, the Juniata River joins the Susquehanna. The Canodoguinet and Juniata are generally turbid, while the main waters of the Susquehanna are usually clear, excepting during high water. Further up the river are many tributaries draining the coat mining regions, and these streams, after heavy rains, bring down enormous quantities of coal dust and culm. During the winter and spring months the river water becomes very turbid, and ex- tremely objectionable from an aesthetic point of view. At stationary low water there is no trouble from culm, and as a general thing the yellow water of the Juniata hugs the west shore of the river. During freshets, however, the culm that is brought down the river is thrown toward the banks when the river is rising, owing probably to the fact that the water surface is convex at such times, and the currents are oblique from the main channel toward the banks. When the river is falling after a heavy freshet there is a slight tendency for the culm to work back again toward the center of the river, as the water surface is then slightly concave. These phenomena account for the fact that often when the river is bringfing down culm none will be found at the intake crib. During long-continued high water, however, caused by heavy freshets along the streams in the coal mining regions, and after the river has become tolerably permanent in its high stage, the culm will not be thrown so far toward the banks, and will be more evenly distributed over the entire cross-section of the stream. The infer- ence is that least trouble would be caused from culm if the intakes were in the general line where the velocity of the river is greatest. This line however, would be less favorable so far as the yellow water of the Canodoguinet and Juniata are concerned, because the turbidity of these streams is caused by yellow clay particles of sub-microscopic size, particles smaller than bacteria, and they move with the currents as freely as the water itself. Therefore, on the falling stream, the yellow water would be drawn over toward the center of the stream. CULM — TURBIDITY. 43 The best place for the intake, therefore, would be between the east shore and the center of the river. Judging from such observa- tions as I have been able to make the present intake is a little too far out ; but the best point is difficult to locate because conditions are different at every flood, and probably the amount of improve- ment that could be obtained would not warrant the trouble and expense necessary to make a change. During the greater part of the time that I have been engaged on this report the Susquehanna River water has been clear and bright. Only twice has there been any trouble from culm, and I have not been able to see the water at its worst. Generally there is very little turbidity except during high and moderately high stages. In the summer months the water is quite clear and bright ; but when the freshets come in the Fall and Spring, the enormous quantity of coal dust brought down from the mining districts renders the water so black and dirty that it is repulsive to sight and disagree- able for any purpose. On two occasions the reservoir has been cleaned out; once in 1888 and again in 1894. On each of these occasions about 6,000 cubic yards of sediment were removed, consisting principally of culm. Were it not that a large amount of this culm was drawn off through the city taps by the consumers, probably the depth would have been much greater. Any improvement in the present water supply must have for one of its objects the removal of this turbidity. A water filthy in appearance, even though the dirt be not of a nature to endanger public health, is as objectionable from an aesthetic point of view as a polluted water. For the removal of turbidity two methods are practicable. One is simple sedimentation and the other is filtration. If the turbidity is of a kind that will permit of the water clarifying itself in a rea- sonable period of time simple sedimentation will suffice. Some- times the addition of a little alum to the water as it enters the settling basins will effect clarification, but at times even this fails to produce satisfactory results, and then filtration must be resorted to. If the turbidity comes from clay it is very difficult to remove, because the particles of clay are very small, in fact are smaller than bacteria, and cannot be seen through microscopes of very high power. A process which will remove particles of this kind will, therefore, remove bacteria. The turbidity caused by culm is quite easy of removal, and if there were no other complications a very simple process would 44 PROPOSBD MUNICIPAI, IMPROVEMENTS. produce quite satisfactory results; but unfortunately, at Harris- burg, at times when the culm comes down there is also a consider- able amount of clay turbidity brought down by several of the branches emptying into the main river above the city. On August 19, 1901, when the river was at the 6-foot stage, due to floods in the vicinity of Wilkes-Barre, I collected two sam- ples of the water, one from the force main at the pumps and the other about half-way between the shore and Forster's Island. The appearance of these two samples was markedly different, the one from the force main being the less turbid, but the more yellow of the two. This sample from the force main contained 600 parts of suspended matter per million, while the other contained 1,000 parts. The sample from the force main was set aside after having been violently agitated, that the rate of clarification might be watched. The results were as follows : Time of Settlement. Turbidity. Percentage remaining in suspen- sion. Remarks. 600 575 500 350 110 80 48 30 35 5 minutes 15 minutes, 37 minutes, 1 hour 96. Nearly all the culm had set- tled to the bottom. 83. 42. 18. 1 hour and 40 minutes, . . 34 hours 13. 8. 48 hours 5. 63 hours 4. This rate of clarification is characteristic of water charged with culm. It will be noted that over half of the suspended matter had settled to the bottom in 27 minutes, while in 2 hours practically all except the clay had been deposited. The clay turbidity disappeared very slowly, 25 parts per million remaining after 63 hours of quies- cent settlement. The other sample taken to the east of the yellow Juniata water, although containing originally 1,000 parts of suspended matter per million, cleared itself after 50 hours of quiescent settlement of all but 20 parts per million. The analyses, while indicating the character of the turbidity of the water during freshets, cannot be taken as indications of the greatest amounts that may be expected. During heavy freshets PROPOSED DAM. rtuBZI> 190' """"^'-'^sr^s-s-'^^ HARHISDUHO LEAGUE FOB PUBLIC IMPROVtMtNTS PLATE XII IMPROVEMENT OF SUSQUEHANNA RIVER IN FRONT OF HARRISBURG PENNSYLVANIA THE CONSTRUCTION OF A DAM PLAN SHOWING LOCATION OF PROPOSED DAM AND LIMITS or POOL AT LOW WATER Scale of FMl V"P^ 1 l-l- rr TTl — 1 ~ _ " ■* -_ '■ " R; z { fx - J. __ ^ « 6 i - P r Ij Ij i — i 1-:: ~l ' a UJ i-"- 1 C 1 i £ i " r p II 1 Ir *" ~ ■ ■ ■ ■ t [■" "' r ■^ 'i-= t%- p - --H- - 1 - -1 + -1 - - - - -- - -t- J^ --'h ^2l - -- w, i?=j^ Hi e 7 fife - ^ X " i^ '4 ? ? » £i 3 - - =; 9 'c±^^ -- B^222!t? "--:!!!^:-::;"= _± ^^ ?/> _ '5^,:,: LL 4t1 _L. -; r 7T^- '■ 111 :::: 1 1 : ±:: ■^.^TTTII M 1 1 1 1 1 1 1 1 1 1 1 1 M 1 1 K» ZOO yx 4 » wo 600 7CN a 30 300 DO 11 00 iZ 00 13 oo UO 1. w »0 ITO leoo 900 ZOOD ZIOO Z200 Z300 Z^OO ZiCC 1600 Z700 ZeOO Z900 3000 SIOO 3100 3300 3400 auo Distances in Feet CROSS SECTION OF RIVER ALONG SITE OF PROPOSED DAM 13000 now Distances in Feet JAMES H.FUERTES Civil and Smutmy Engimlc* stPTEMBur not MOO ioOO PROFILE OF RIVER FROM PROPOSED DAM TO WOODBINE STREET PLATE XIII SUSQUEHANNA RIVER FRONT AFTER CONSTRUCTION OF DAM Scale of Feet Red Lines are City Sewers. Figures show sizes of Sewers. Arrows show direction of flow Below mouths of Sewers when the nver is rising.or ata stationary low stage JAME5 H.rUCRTLS Civil and Sanitahv Enginccr SEPTCMBCn 1901 HARRISBURG LCAGUC FOR PUBLIC IMPROVCMLNTS PLATE XV MISCELLANEOUS CURVES "88B 1889 1690 tV ■891 A— ^ 1894 .sas 189& 189! — ^ 1898 R P=V ^ ^ n N N ^^^ ^ AVERAGt DAILY WATER CONSUMPTION IN HARRISBURC FOR EACH MONTH FROM laeaTo lase inclusive CONTINUOUS RECORD OT FLUCTUATIONS OF HEIGHT OF RIVER SURFACE AT HARRISBURC FROM 1895 TO 1900 INCLUSIVE ' January FCDruary Marcn aprll M« June July Aueusi September ooooer NWcmBei- December 1 " Si: 1 / f\ A \ I f \ jA ^ V,, ^ -^ n- l\ r- ^ \ r\±„^-id,T " > -- — -= ,-— — ^..^ :; -==^ ■ \ 1900 January Februar> Marcn April May June July •ueust icptcmoer Octotwr November December ^ ,. c '5 s «, A J, lU /^ J „ Low W« eron«,l ■^ - ;^^ ,— ...^^ ic^ =J^^ 1899 :oo iBBS '889 1890 1891 189; 1B93 1894 IB9S iB96 'B97 ,698 i » M "AVERAGE DAILY PER CAPITA WATER CONSUMPTION FOR EACH YEAR FROM 1868 TO 1696 INCLUSIVE Population taken from curve below, total >ear|y water consumption taKen from reports ol Water Department 800 K :o e3o »w «» (8W WTO leso «» i90o .*£iio isio isjo mo 1 ■hif / / si »,' P! / / > ^ '4' r / // Ai .■ y ■ /¥ ' w) / /'^ //'/ I ^y" V 1 r^ K h ^ . y ^ -^ 1 ^~-^o J\^ r\, - / '^ J^-^ -r^ J « Lo.lh erotHOJ ■ ■ — ■ ^ 1898 3 .K January February March April May June JUIJpl august ieptemDer October MovertiDer Oecemtrer • -v- ^^ A -^ A V > / v^ \r\i\ \ M '^'--^ CBwTW ^^ -^ -^^ ^'^-^- V A , r^ - 'r " H 1897 _ January February March April Ma, June July AuRUSt September Ortober November December \ \ \ 1 \ ^ \ ,' \ \ f vyv 1^ A "' J v/U "\ r ^_f — t' ■ ^ ^ \ K_ t ^ fl l.o« water of iBOl ~ ^"— . ~ 1896 s " January Februjry Marcn April May June i\iry August September oaober November December * m £i i« ? " S 10 5 10 A I ' «> ' »'' ^-.^ ^ >-^--, ■ ■- J S Lowwaicrof I8P3 ^- -^ . — ■-^— . s ■' 1695 IMPROVEMENT IN SANITARY CONDITION OE RIVER. 65 Amount brought forward $37,868.40 Fourteenth street, State to Walnut, including manholes and con- nections with sewers on State and Walnut streets, complete. . . . 1,344.00 Market street, Fourteenth to Evergreen, including manholes and reconnecting catch basins, complete 4,176,00 Total $43,388.40 SEPARATE SEWERS. For the district between Second street and the river, between Bar- bara avenue and Locust street, including manholes, flush tanks and remodeling house connections, complete $16,790.00 Between Market street and Blackberry avenue, and Market Square and the river, including manholes, flush tanks and remodeling house connections, complete 3,060.0O Race street, Paxton to Hanna and Indian alley, including man- holes, flush tanks and remodeling house connections, complete. 6,333.00 Third street. Blackberry avenue to Meadow Lane, Meadow Lane, Third to Second street, Court avenue. Mulberry to Meadow Lane, and Second street. Mulberry to Washington street, includ- ing manholes, flush tanks and remodeling house connections, complete 4,896.00 Cowden avenue. Boas to North street, including manholes, flush tanks and remodeling house connections, complete 3,900.00 Total $83,868.00 SUMMARY. Total cost of combined sewers $43,388.40 Total cost of separate sewers 33,868.00 Total cost of new sewers recommended $77,356.40 THE IMPROVEMENT OF THE SANITARY CONDITION OF THE SUSQUEHANNA RIVER. The river front should be the pride of every citizen of Harris- burg, as there are few cities which are situated so favorably in this respect. Usually the river fronts are usurped by manufacturing and industrial interests, and all possibilities for pleasure and re- creation along the water are sacrificed for the benefit of industries comparatively few in number. In Harrisburg nothing stands in the way of making the river front one of the most attractive promenades in the country, ex- cept the fact that at times of low water the decomposition of or- ganic matter along the shores gives rise to odors that are dis- agreeable and ofifensive. There is in addition to this ofifensive- ness a danger lurking in the pollution, a danger which may affect 5 'bb PROPOSED MUNICIPAL IMPROVEMENTS. the general health of the city by giving rise to malarial and in- testinal diseases. The pollution comes from several sources and is aggravated by the character of the river bottom. Generally speaking the bottom is flat and the banks rise steeply up to the level of Front street. As the water surface falls during the late summer, quite large areas are exposed at the foot of the sieep banks. These become coated with greasy matter from the sewers, particularly just below the mouths of the latter, and the odors arising from the decomposition of this matter are extremely un- pleasant. On Plate X will be seen a plan of the river front in its present condition, showing the outlets of the city sewers, with arrows in- dicating the general directions in which the sewer discharges will be carried when the river is low. When there is a fair flow of water, say at about the 2^ foot stage, there will be no offensiveness, because of the dilution of the sewage before it has gone many feet from the shore. It will be seen that the shore line is quite irre- gular, being formed of little promontories and bays. In each of these bays, sewage, at low water, will gather and pollute the shores by its decomposition. Another source of the disagreeable odors, aside from the city sewage, will be found in several private sewers from houses along Front street. Many of these sewers do not extend to the water, but discharge on the banks. This should be discontinued at once, or the sewers extended out below low-water mark. On the west side of Front street, from Herr to Calder street, there is a row of buildings the outhouses from some of which are on the edge of the high bank of the river. Some of the houses have sewers, but these extend only to the edge of the river bank. These nuisances should be summarily abated by the laying of small sewers back of the properties and leading to one of the large sewers near- by, and by the enforcement of ordinances requiring the use of water closets and the abandonment of privies. Aside from this sort of pollution, there is another source of dis- agreeable odors arising from natural conditions, and which may be equally dangerous as far as spreading malarial affection is con- cerned. Owing to the great width of the river, which averages about 3,300 feet where it flows past the city, and owing to the small flow during summer months, large areas of the river bed are ex- posed at times. The irregularity of the rocky bottom affords op- portunities for the stagnation of water in pools of greater or less SUMMARY. 67 area, and these form favorable places for the breeding of mosqui- toes, the general medium for the transmission of malaria. The corrective measures for these evils are simple. In the first place let us inquire into the question of how much sewage the river may safely receive. The minimum flow of the river, from the best data I have been able to obtain, is about 2,300 cubic feet per second. This amount of flowing water, if the sewage could be properly dispersed through it, would safely receive the sewage of 700,000 people. The pollution coming from cities above, while considerable in amount, as has already been shown on page 39, need not be considered as a factor in the disposal of the sewage of Harrisburg. We see, therefore, that provided the sewage is properly discharged into the river, it will cause no offense what- ever. The limits to which pollution may be carried without mak- ing the water offensive are pretty well known from the records of many cities in the United States and Europe. These observations summarized may be stated as follows : Flow of stream in cubic feet per second per 1,000 persons dis- charging sewage into it. Condition. Less than 3 The water will certainly become oflEen- sive. 31^ . . . . A nuisance may or may not result, ac- cording to local circumstances. 3 The water would probably not become offensive. 3 5^ to 4 Generally safe. 6 and more No danger of offensiveness. There is, therefore, no question but that the river can take the Harrisburg sewage if it is discharged into the current in a suit- able manner. The requirements are that a considerable quantity of water should flow between the ends of the sewers and the shores, at low water. When this condition is fulfilled there will be no trouble from the sewers, because the sewage will be diluted, and will be prevented from being washed ashore to decompose under the influence of the sun and the action of putrefactive bacteria. There is in some places, however, a difficulty in carrying out this policy, because of the shallowness of the river. It will be necessary not only to extend the sewers but also to place the pipes 68 PROPOSED MUNICIPAI, IMPROVEMENTS. down in an excavated trench, so that the water may flow over them. If they were laid on the bottom without any excavation, they would have to be protected by piles of stone to hold them in place, and as these piles would simply be obstructions at low water, behind which the sewage would be carried by eddies and currents, the conditions would eventually become worse than they now are. It would not be necessary to carry them out of full size, however, because only the dry-weather flow of the sewage would have to be taken out from the shores. During rains the sewage would be so diluted with rain water that its occasional discharge at the pres- ent outlets would not be offensive. Small pipes extended from the present outfalls, with overflows to permit the escape of rain water, would rectify the troubles from sewage pollution of the shores by the city sewers. While this would correct the greater part of the trouble, I can- not say with confidence that it would afford entire relief from of- fensiveness, because of the large area of shore lying but a few inches above the water level at low water. These shores remain damp by capillary attraction, and are in themselves capable of giving out very unpleasant odors. To rectify this it would be ad- visable to fill up the low ground from low water to a height above the ordinary high summer stages of the river. By reference to the diagram on Plate XV it will be seen that this is about 4 feet above low water. As this filling is done the shore line should be straight- ened out to obliterate the bays and projections now existing, and the front along the water's edge should be protected by a wall of masonry, or by a paving of stones or concrete. If the filling is carried up to the height named, there would be formed a fine gent- ly sloping shore that would rarely be covered by the river during the summer months. If it be carried to a height of only 2^ feet, it will rectify the trouble from odors, but will be subject to frequent flooding every year during the summer months, and hence would be useless for the purpose of a playground or public promenade. The cinders from the iron and steel works would be excellent material with which to make the filling, as they can resist a con- siderable amount of scouring action without becoming dislodged. Paving the edge of the filling on a slope of about two to one would make a better finish than a vertical wall, from all points of view. A paving of Portland cement concrete about 6 inches thick, with expanded metal sheets embedded in the mass, would make an ex- cellent protection at relatively small cost. The concrete should be A WATER BASIN. 69 well made, however, and the top inch in depth of the surface should be well made of cement mortar mixed half Portland cement and half sand, the latter being put on at the same time the concrete is laid, so as to be thoroughly bonded to it. These works would, so far as protection of the shore and pre- vention of disagreeable odors are concerned, rectify the trouble. There would still be present, however, the musty smell coming from the exposed parts of the river bottom, and the danger of malarial affections, to which reference has already been made. The outline plans for this improvement will be found on Plate XL All the difficulties regarding the sewage pollution of the shores and the exposing of the river bottom may be overcome, however, by builcling a low dam across the river near the south end of the city. I have found a suitable site for such a dam below the Phila- delphia & Reading R. R. bridge. The location is shown on Plate XII. Along the line of this dam the river bottom is a bed of lime- stone, and is nearly level from one shore to the other. On Plate XII is given a section across the river on the line of the dam. It will be seen that the greatest variation from a horizontal line does not at any place exceed four feet. The site below the railroad bridges was selected because of the possibility of the formation of ice blockades, which might endanger the railroad bridges should the dam be placed above them. To establish the proper height for the dam and its effect on the surface heights of the water, a careful survey was made to ascer- tain the present slope of the water surface at a medium low stage. I find that the economical height would be about 4J feet above the average river bottom, or the elevation of the crest would be 291.9 feet above sea level. A dam of this height would cause comparatively quiet water as far up as Maclay street. At Maclay street there is quite a rapid fall in the river bottom, and to throw the water, during extremely dry weather, further up than Maclay street, would require a dam of considerable height. At the height selected all the flats would be permanently submerged from the dam to above Maclay street. This would relieve the present un- satisfactory condition during dry weather. It would also, as may be seen by reference to Plate XIII, permanently cover the low flat shores along the water edge on the Harrisburg side, and would solve the question of the pollution of the shores by covering the ends of the city sewers, and allowing a current of clean river water 7o PROPOSED MUNICIPAL IMPROVEMENTS. to flow between them and the main shore line. Some of the out- falls would have to be extended by the addition of a few lengths of pipe. These should be of the same sizes las the present out- fall pipes, and no overflows would have to be provided, as would be the case if the dam were not built. It would not be necessary to build an intercepting sewer along the river bank, to take the sewage below the dam. In fact it would be impossible to maintain such a sewer, because the available slope is so slight that the sewers would soon fill up with deposits, and would become a worse nuisance and more potent source of danger than now exist. The efifect of the discharge of the sewage into the pool formed by the dam will not be more injurious upon the char- acter of the water than if the dam were not built, because there will always be a perceptible current along the river shore, even during periods of driest weather. At the ordinary low summer flow, say about 5,000 cubic feet per second, the mean velocity through the reservoir will be a little less than 1 ft. per second. With a quantity of flow corresponding to the ordinary small summer rises, say about a 2j-foot rise, the water would flow over the dam about a foot deep, and the mean velocity through the reservoir would be about a foot and a half per second. It will thus be readily ap- preciated that there can be no stagnation in the pool formed by the dam. At higher stages of the river the velocity increases, being over 2 feet per second when passing a quantity of water corresponding to a 4-ft. rise, and reaching 8 feet per second during the big floods. It will be desirable, however, to provide openings through the dam near either shore of the river, with a combined area sufficient to discharge the minimum flow of the river, while holding the surface of the water in the pool level with the crest of the dam. The opening on the west end of the dam would have a tendency to draw the yellow water of the Juniata River and Canodoguinet Creek to the farther side of the pool, while the open- ing through the east end of the dam would draw the principal cur- rent along the shore line in front of the city, and have a tendency to draw fresh water between the sewer outfalls and the bank, as well as to keep the water in which the sewers discharge in con- tinuous motion. It will be unnecessary to provide movable sec- tions in the dam, because there will be very little tendency for the pool to silt up. At times of the year when the river carries much sediment in suspension it is at a fairly high stage, and the velocity through the pool will be sufficient to carry the suspended matter DESIGN FOR DAM. 71 over the dam. During heavy freshets, any matter which may have been left by the tail ends of the small floods while the river was falling would be picked up and washed out much the same as now occurs. The effect of the dam on the heights of the floods will be insig- nificant. Thus with a quantity of water corresponding to a 4-foot rise the dam will raise the water level to the 7-foot mark on the gauge. When the water rises to a height of about 4^ feet above the top of the dam, the increased slope necessary to discharge the water through the reduced area over the top of the dam will amount to only a few inches, and with greater floods the efifect of the dam will not be noticeable. As a general thing when water flows over a submerged dam with a depth equal to the height of the dam, the surface of the water will give no indication that a dam exists. It is therefore readily seen that this low dam will have no effect whatever on the heights of destructive floods. When the river is high enough to go over the large valuable islands, the flood heights will not be raised by the dam by so much as half an inch above the normal. In other words, the flood conditions will be the same as if there were no dam across the river. I have designed for this dam a structure of steel and concrete on the Ransome system. I have chosen this form of construction because of the security it ofifers, and the ease and cheapness with which the dam may be built. The method of construction would be as follows : A row of piers would be built across the river, each 3 feet wide and 6 feet long in the direction of the current, and of sufficient height to reach the proper level. The piers would be spaced 6 feet apart in the clear, excepting at the shore ends. They would be constructed of concrete made of Portland cement mortar, having bars of twisted steel extending through them vertically, and reach- ing down 4 feet into the solid rock bottom of the river. Holes would be drilled in the rock considerably larger than the size of the bars, and after the bars were in place the holes would be re- filled with Portland cement. The concrete piers would then be built enclosing these twisted bars, thus tightly binding the whole mass to the bed rock. After the piers were up a steel and concrete bridge, or platform, would be built over the tops, connecting them to form a low bridge. The ends of the vertical twisted steel bars in the piers, would extend up into, and reach nearly through, this 72 PROPOSED MUNICIPAI, IMPROVEMENTS. top platform, thus binding the whole mass together in a mono- lithic structure. After the completion of this part of the work, steel and concrete beams, 12 inches square, would be dropped to the bottom on the upstream faces of the piers from one end of the dam to the other, excepting across the two end openings, to which reference has been made above. Planks, 4 inches thick, cut to the right lengths, would then be placed vertically with their lower ends resting against the concrete beams on the bottom, and their upper ends against the platform over the tops of the piers. Behind the plank- ing would be deposited a bed of gravel sloping toward the bottom upstream, and the face of the gravel filling would be protected from wash by a paving of large stones. The piers on either side of each opening would be made much heavier than those in the rest -of the dam, and would be carried up stream to form retaining walls against which the gravel filling would abut. The bottom of the channel through these openings would be lined with concrete after first preparing the natural bottom of the stream, and on the down- stream face this concrete bottom would extend a hundred feet, and reach sideways to a width of about 50 feet. This will be neces- sary to prevent the bottom from wearing away, and the consequent risk of destroying the dam. There will be no necessity of protect- ing the rock bottom below the face of the rest of the dam, because when water is flowing over the dam it will fall upon a water cushion on the downstream side, and the depth of the cushion will increase more rapidly than the depth of water over the dam. Also when the flow is small, the river water is comparatively free from gritty scouring material, while during floods when the water is heavily laden with it, the existence of the dam will cause comparatively little change from present conditions. The method of construc- tion of the dam can be readily understood from the drawings given on Plate XIV. There is no question concerning the stability and durability of a structure of this kind. Where steel bars are thoroughly embed- ded in a rich Portland cement concrete, they are perfectly pro- tected against rust and will last practically forever. The estimates of cost of the different plans for improving the condition of the river are as follows : I. Plan shown on Plate XI. River front filled out to low-water line and raised to above summer flood height. Sewer outlets ex- POSSIBLE PROMENADE. 73 tended 50 feet beyond new shore line ; sloping edge of esplanade paved with stones. Cost, complete, $61,900.00 2. Plan shown on Plate XI. River front filled out to low-water line and raised to summer flood height ; sewer outlets extended 50 feet beyond new shore line. Sloping edge of esplanade paved with ■concrete and expanded metal. Cost, complete, $74,100.00 3. Same as above, but retaining wall built at edge of esplanade instead of paved slope. Cost, complete, $105,000.00 4. Plan shown on Plates XII and XIII. Dam built across the river at Conoy street. Some of the sewers extended further into the river channel. Cost, complete, $55,000.00 The advantages and disadvantages of the different methods will now be briefly discussed. I would give the preference in point of efficiency to the method in which the dam is used. It completely solves the question of nuisances and removes the cause of a large source of malarial infection. It also provides a large expanse of water upon which boating may be comfortably indulged in, and will prevent the uncovering of a large stretch of fore-shore, which is at present both unsightly and offensive. It will be seen by reference to Plate XIII that the extreme limits between low water and high summer floods will not average more than 20 feet in width past the city front, with the present natural shores, and that a small amount of filling along the water's edge will cut this limit down to a few feet, and provide a pretty promenade, which would very rarely be submerged between the months of May and Novem- ber. The other plans, while correcting the nuisances so far as the shore line is concerned, do not provide for the submergence of the flat river bottom at low water stages, and are therefore not so perfect. Since the cost of the plan in which the dam is used is no higher than the costs of the other plans, I recommend that the dam be built as the most satisfactory means of correcting the 74 PROPOSED MUNICIPAL IMPROVEMENTS. evils. The effect of the construction of the dam on the quality of the water at the intake of the water works was discussed on page 46 in the consideration of the improvement of the water sup- ply. I am informed that the building of the dam by the city would interfere with no rights of navigation or business, as parlies now removing culm and sand from the river do so by permission, and have no rights paramount to those of the general public. It would therefore be unnecessary to provide a lock for the passage of boats. Such a lock could be built, however, if desirable, but I have not added its cost into that of the project. The effect of the dam on the deposits of culm and sand would be difficult to foretell. There will certainly be no change of con- dition a hundred feet or more below the dam, while above the dam the deposits will probably be further upstream than they now are ; but it is largely a matter of speculation, because cross currents caused by the rugosities of the bottom may be somewhat changed in intensity by the slight checking of the velocity caused by the erection of the dam. APPENDIX I. Table Showing Density of Population in Hanisbarg, Pa., in 1900. from U. S. Census. Population Ward. Population. Land Area of Ward in Acres. Average Density per acre. Area of Set- tled portion in acres. Average Den- sity per acre of settled por- tion. 1, 3, 3, 4, 5, 6, T, 8, 9, 10, 3,909 4,269 2,286 3,641 4,313 11,756 7,198 4,435 6,455 1,906 541.18 298.13 59.18 96.78 65.81 237.71 505.91 232.86 237.76 315.00 7.2 14.3 38.5 36.4 65.6 49.4 14.2 19.1 27.1 6.6 158.8 125.1 59.18 96.78 65.81 237.71 151.2 99.7 205.5 103.8 24.6 34.1 88.5 36.4 65.6 49.4 47.6 44.6 31.5 18.5 APPENDIX II. Table showing number of deaths from typhoid fever, by months, in Harris- burg, Pa. , for the fiscal years 1898, 1899 and 1900. Data from Annual Re- ports of Sanitary Department. SAND ANAI,YSBS. 75 u ;h Year. 1 ^ S i 1—, 1 i 1 O 1 1 (U Q 1— > 1 3 o El 1898 3 2 1 3 1 1 1 3 14 1899, 2 2 1 1 1 2 1 4 1 3 18 1900 1 1 3 2 1 2 3 6 4 23 The above records show that from about the first of September to the first of January there is generally very little typhoid fever, most of the deaths occuring during the winter, spring and early summer months. In other words when the river begins to rise in the fall, washing out the deposits from the long stretches of quiet water, and from the pools formed by dams above Harris- burg, typhoid fever begins to appear in the city. During the time the river is subject to flashy rises, that is from November to May, the fever continues intermittently, holding over generally for from one to three months in the summer, according to the length of time necessary for the disease to incubate and run its course in individual cases. APPENDIX III. Sand Analyses. The sand obtained from the Susquehanna River at Harrisburg is of very good quality for use in slow filters. The following analy- ses show the quality of the Susquehanna, as well as of a few other, sands. Samples i to 6, inclusive, were obtained at the sand heaps at Vine street, while 7 to 12, inclusive, were from the pile at Dela- ware avenue. No. of Sample, 1, 3, 3, 4, 5, 6, 7, Where Obtained. Susquehanna River at Harrisburg, Effective size, mm. Uniformity Co-eflacient. 24 29 29 28 29 28 39 1.6 1.3 1.3 1.4 1.3 1.4 1.6 76 PROPOSED MUNICIPAL IMPROVEMENTS. No. of Sample. Where Obtained. Effective size, mm. Uniformity Co-eiBcient. 8 Susquehanna River at Harrisburg, 38 1.5 9, (( (< t( (( 37 1.6 10, " " " " 37 1.6 11 .1 << i< 28 1.5 12 >' " " " 28 1.5 13 Cape May beach, coarse 38 1.9 14 De aware River, bar sand, .... 85 3.1 15, Cape May beach, fine sand 84 1.5 The term "effective size" denotes the size of the particles of the sand which practically control the rate at which the water will filter through it under different heads. This size of grain is neither the finest nor the coarsest, but averages the size such that io% of all the grains of the sample is finer than itself. The uni- formity coefficient, as its name denotes, expresses the uniformity in size of the grains in the sample ; not the ratio of the largest to the smallest grains, but the ratio of the size having 6o% of the grains smaller than itself to the size having io% smaller than itself. The Susquehanna River sand is quite free from dirt, pieces of bark, wood and other matters usually found in sands taken from large rivers. In point of fineness it would be called a very good sand, being neither too fine nor too coarse, and having a very low uniformity coefficient. The sand contains a very considerable amount of coal particles but these would not affect its value for use in slow filters. The sand contains a good deal of shale, which would have a tendency to slightly increase the hardness of the water, but not to such an extent, however, as to be detectable in the practical uses to which the water would be put. I do not believe that this sand would be suitable for use in rapid filters without a great deal of washing, to remove the small par- ticles and the coal. Sand for use in rapid filters should be rather coarse, very uniform in size of grain, and composed of particles of about the same specific gravity. If there is much variation in these particulars, after washing a filter the sand grains are likely to re- arrange themselves in the order of heaviness and size, leaving all the fine grains on top and the coarse ones at the bottom. This will give very inferior results in filtration, because any matter which could pass through the thin layer of fine sand on top would COST AND DEPRECIATION. 77 go without difficulty through the lower layers of coarse sand, and also because the fine sand on top will clog up very rapidly, making frequent washing necessary. APPENDIX IV. Unit Prices. Following are the unit prices used in making up the estimates of cost of the different works. Clearing and grubbing, per acre $100.00 Earth excavation, per cubic yard 35 to 50 cents Overhaul 5 cents per 1,000 lineal feet. Rock excavation in deep trenches, under railroad tracks, etc. , per cubic yard 4.00 Rock excavation, open cut, per cubic yard 1.50 Brick masonry, per cubic yard, 12.00 Arch culvert masonry, per cubic yard, 15.00 Foundation masonry, per cubic yard, 10.00 Paving, per square foot 10 to 30 cents Portland cement concrete, on centers, per cubic yard, 7.00 Portland cement concrete, in forms, per cubic yard 6.30 Cast-iron pipes, hauled, per ton, 39.00 Telephone lines, per mile 600.00 Stone waU fence, per foot 30 cents Iron fence, per foot, 1.00 Dressing and seeding banks, per square yard, ■ 8 cents In the calculation of the annual costs of operation and mainte- nance, the allowances to cover the replacing of the works, from time to time, have been based on the values given in the following table : Depreciation Table. Structures, Apparatus, Etc. Life in Years. Annuity on One Dollar. Masonry Conduits and Sewers, Covered Masonry Filter Beds, . Covered Reservoirs Permanent Buildings, Cast-iron Pipe, Machinery and Tools, Engines and Pumps, ' . . Electric Light Plants Telephone Lines, Permanent. Permanent. Permanent. 100 80 30 30 30 10 .00165 .00311 .03732 .03733 .03723 .08734 78 PROPOSED MUNICIPAI, IMPROVfiMIjNTS. APPENDIX V. Turbidity of the Susquehanna River Water. o •6 1 i 1. "3 >, P^O) s,irt <4H >>o oi o (U o 11 •s^ °d -d -d t« 1 c4 u a f 3 -1 M -1 M 15 CO e Pk y jO! CL, H 1, . . West shore, . 1,000 33 hours, . 150 1-X 5 min. , . . Decided. 2, West shore, . 1,000 38 hours, . 150 1-U 5 min. , . . Decided. 3, West shore, . 1,000 33 hours, . 150 3 5 min., . . Decided. 4, West shore, . 1,000 33 hours, . 3->^ 5 min., . . Faint. 5, West shore, . 1,000 34 hours, . 3 5 min. , . . Faint. 6 Intake, . . . 34 hours, . 36 hours, . '50 150 2-X 1 hour, . . 1 hour, . . Very faint. Very faint. 7, West shore, . "i.boo 8, Island, . . . 38 hours, . 753 503 45 min., . . 34 min. , . . 2.5 hours, . Very faint. g Intake, . . . Very faint. Very faint. 10, West shore, . 'i,bob 40 hours, . 7 11 Intake, . . . 40 hours, . ■50 50 3 1 2. 5 hours, . 5 min. , . . Very faint. Very faint. 13, East shore, . ■ 600 13, West shore, . 800 11 hours, . loo s-'A 8 hours. Decided. 14, Island, . . . 100 12 hours, . 80 1-^ 3.8 hours, . Faint. 15, Intake, . . . 150 13 hours, . 25 t-U 3.5 hours, . Faint. 16, East shore, . 100 12 hours, . 20 5 min., . . Very faint. 17, West shore, . 300 18 hours, . 100 3-^ 5 min. , . . Very faint. 18, Island, . . . 100 13 hours, . 25 1 5 min. , . . Very faint. 19, East shore, . 100 16 hours, . 5 1 5 min., . . Very faint. 20, West shore, . 300 17 hours, . 100 3 5 min. , . . Very faint. 21, West shore, . 300 17 hours, . 100 2-'A 5 min., . . Very faint. 23, West shore, . 300 17 hours, . 100 2 5 min., . Very faint. 23, West shore, . 300 17 hours, . 100 l-}( 5 min. , . . Very faint. 24, East shpre, . 100 18 hours, . 5 1 5 min., . . Very faint. 25, West shore, . 300 35 hours, . 50 ^/z 5 min. , . . Faint. 26, West shore, . 300 35 hours, . 50 2 5 min. , . . Faint. 27, West shore, . 300 85 hours, . 50 3 5 min., . . Very faint. 28, Intake, . . . 50 . . ^-'A 5 min., . . Faint. 29, Intake, . . . Intake, . . . East shore, . 50 50 300 3 1.5 hours, . 5 min. , . . 5 min. , . . Faint. 30 Very faint. Very faint. 31, 4 hours, . '25 32, East shore, . 300 4 hours, . 35 2-A 5 min. , . . Clear. Samples i to 15 inclusive were filtered through filter paper, and the persistency of discoloration led to the discovery that the color was due partly to the filter paper. Several makes were tried, with the same result. The rest of the samples were filtered through absorbent cotton, which gave no color to the water. The nomenclature used in describing the turbidity of the efflu- ents, viz : Decided, Faint and Very Faint, indicates that the water was clear in all cases, but that a slight yellow color was discernible relative; turbidity o? water. 79 when compared with distilled water in deep glass tubes. Turbidity- is called decided when more than 6 parts per million of clay are held in suspension ; faint when 3 parts, and very faint when 2 parts or less remain in suspension. Turbidities as high as 6 parts per million will not render water turbid enough to be noticeable. It will be perfectly clear and bright in a tumbler, and would not be called turbid unless compared side by side with distilled water. All the above samples were, therefore, satisfactorily clarified in these experiments. In the experiments where the period of coagulation was but 5 minutes, the samples were violently agitated in order to hasten the process. In all the samples, excepting Nos. 12 and 24, the turbidity was caused by the clay in the Juniata water. Nos. 12 and 24 were taken so far to the east that the effect of this yellow water was not discernible. In the column headed "Where Collected," Nos. i, 2, 3, 4, 5, 7, 10, 13, 17, 20, 21, 22, 23, 25, 26 and 27 were taken 250 feet east of the west shore of the river, and represent the yellow Juniata water. Nos. 8, 14, and 18 were taken about 50 feet east of the east shore of Forster's Island, and represent a dilute mixture of the Juniata and Susquehanna waters. Nos. 9, 11, 15, 28, 29 and 30 were taken opposite the intakes of the water works, and represent the char- acter of the water, on the day the samples were taken, that was being supplied to the city. Nos. 12, 16, 19 and 24 were taken about 25 feet out from the east shore, and represent the sewage- laden water along the shore. Nos. 31 and 32 were taken from the center of the main channel of the river on the Harrisburg side. On August 30, 1901, at a low stage of the river, samples were taken over the line of the intake pipes to test them for chlorine, or salt, in order to ascertain whether the water nearer the shore would show a greater amount of chlorine than that in mid-stream. The results were as follows : Sample. Where Taken. Parts of Chlorine per Million Parts of Water. 1 At intake 9 2, 3 4 5 500 feet from shore 250 feet from shore, 100 feet from shore 25 feet from shore, 10 10 10 10 8o PROPOSED MUNICIPAL IMPROVEMENTS. These analyses show that on that day the effect of the sewage of the city, as indicated by the chlorine in the water, could not be detected, and that the chlorine was evenly distributed throughout that part of the width of the river from which the samples were taken. The average amount of chlorine in the Ohio River at Cincinnati is about lo parts per million, or about the same as shown by these analyses. Respectfully submitted, JAMES H. PUERTES. -«3« REPORT ON A PARK SYSTEM FOR HARRIS-^ BURG, PENNSYLVANIA. The study for the development of a system of public reserva- tions and the general improvement of Harrisburg has included the appearances of the city as a whole, because attractive outlooks and agreeable surroundings are quite as important in the daily walks of life as the complete change of scene which the more in- accessible country park offers. I.ANDSCAPE FI^-TURDS. The dominating landscape features of the city proper are the river, where a mile of frontage controls five or more hundred acres of open space, which is in itself an ever changing, always beauti- ful landscape (ill. 1-2-3), the high tree-covered bluffs of the Pax- ton Creek valley, with its fringe of trees (ill. 4-5-6-7-8-9).* Stand upon Mulberry or State street viaducts and look over this valley, and imagine the bluffs, now covered with foliage, reduced in ap- parent height from thirty to sixty feet by the removal of the trees, the denuded slopes scarred with raw gullies and defiled with rubbish (ill. 10). Look again at the masses of fine foHage along the banks of Paxton Creek. It would be a public calamity if all the luxuriant greenness was to be swept away, exposing the back- yards of hundreds of dwellings, and destroying the shade and ver- dure from which the occupants of these homes gain so much. CITY EESEBVATIONS. The city should acquire as much of the river frontage as pos- sible, the smaller islands in the river, including the easterly shore and two ends of Hargest or Forster's island, the wooded bluffs of Paxton Creek valley, and in addition to what they now control,, enough more of the banks of the creek to preserve the trees. All. of this land is of little value for agricultural or commercial pur- poses, whereas its value as an element of beauty in the city limits is beyond price, for if destroyed no money could replace it. *Some of the most representative illustrations are given: Nos. 8, 11, 15, 22,. show beautiful spots near the city ; Nos. 7, 34, 43, 64, show garden-touches. 6 S2 PROPOSED MUNICIPAL IMPROVEMENTS. PLAYGROUNDS. Upon such lands many pleasantly shaded, small play-grounds could be established at such frequent intervals that the children can use them daily instead of being compelled to play in the streets (ill. ii), or upon the sewer-polluted shores of the river (ill. 12). Furthermore these reservations provide a place for a system of shady roads and paths connecting the various larger parks are pro- posed. It is recommended also that play-grounds be established upon school and church properties, especially in sections of the city somewhat removed from the proposed reservations, or where the land values are high. SMALL CITY PARKS. Within the city limits one or more small parks should be estab- lished within easy walking distance of the homes of citizens who have no means for driving, and cannot well afiford the frequent use of the trolley. Such reservations should have attractive land- scapes, quiet walks, and resting places where nervous and tired people, the sick, and mothers with their children can secure a complete change of scene, freedom from noise, boisterous games, and the constant passing of people. The State Capitol grounds could be so designed as to serve this purpose admirably for the northern section of the city, and at the same time give the great building under construction a proper set- ting. In the southern section the George F. Mish property, be- tween Paxton and Cameron streets, and a wooded creek-valley below it, form an ideal site with a fine view from its summit, fine trees surrounding it, and rich soil. OUTLYING RESERVATIONS — RESERVOIR PARK RIDGE. The most important landscape feature outside of, and near the -city limits, is the ridge upon which the City Reservoir Park, the great summer playground of the people, is located. From its summit, the highest point near the city, there is a fine panorama •of the distant mountains, the river, the town and the ridge. Three groups of forest trees crowning the ridge are conspicuous and attractive objects in view from many places in the city and valley. Reservoir Park includes a small part of one slope only. It should l3e extended to include the whole summit of the ridge and about •one-half of the northerly slope, down to a point where a planta- THE CREJAT COUNTRY PARK. 83 tion would shut out the immediate foreground of houses in the valley, but not the fine mountain range beyond, or the river in the distance. The southerly slope is included down to Market street to connect with the proposed filtration farm which may properly be a part of the park system. There is a great need of more room at Reservoir Park to ade- quately accommodate the constantly increasing number of visitors, to provide more varied amusement, and to establish interesting and instructive plantations. With all additions and improvements this park, however, must continue to be a holiday park for occa- sional enjoyment, not an everyday playground for the many, as it is too far from the crowded portions of the city. THE GREAT COUNTRY PARK. Every growing city has acquired, or should have, one or more large country parks where broad reaches of landscape may be held for all time for the benefit of the people. Such parks can be ac- quired only at a time when land can be secured at a low cost, and they must necessarily lie outside of the thickly settled portions of the city. When the city grows to and about them, the full value of the investment is realized. The opportunity for a great country park at Harrisburg lies to the north of the city in the tract known as Wetzel's Swamp, which includes about five hundred acres of swampy and dry land, framed in with wooded blufifs on the one side (ill. 13-14), and a line of fine old willows along the canal on the other (ill. 15). As it stands to- day it is a natural park, with beautiful passages of landscape (ill. 16) and fine vistas over great stretches of meadow land to distant hills beyond (ill. 17-18). It is rare, indeed, that a city can secure a property having all the elements of a park landscape, its border- planting (ill. 19-20), groups of fine trees (ill. 21-22), splendid indi- vidual specimens (ill. 23-24), and woodlands, carpeted in spring with numerous wild flowers. Here also there is a comparatively level and perfectly dry up- land, that, with but little clearing, and the removal of pens and sheds (ill. 25-26), can be made available for picnics and games. In the meadows masses of brilliantly colored flowering plants (ill. 27), which the uplands cannot produce, are found, giving color and ef- fect at different seasons of the year. This region is quite acces- sible by steam and electric cars, and there are roads (ill. 28-29) at several points across the meadow, and for a long distance along 84 PROPOSED MUNICIPAL^ IMPROVEMENTS. the boundaries. The swampy condition (ill. 30.) which prevails upon much of this land, can be remedied, for there is abundant fall for all drainage through Fox's Run and Paxton Creek. PIvEASURE ROAD SYSTEM OUTLYING ROADS. An outlying drive of thirteen miles is indicated from Cameron Creek to the country road at the extreme end of Wetzel's Swamp, thence along the easterly bluffs to the city parkways, and back to Cameron Creek. Wetzel's Swamp is crossed by four roads (ill. 31-32), while others follow along part of the canal on the west, and for two-thirds the distance along the easterly bluffs. These could readily be connected and made safe for public travel in good weather at small expense. Following the practice in other parks, such temporary roads could be closed during bad weather until funds were available for their permanent construction. As these roads are in places for permanent park roads, the work done upon them would not be lost. The outlet of such a road system would be, for the present, over Cameron street to the proposed parkway at Maclay street. Below the city, connection with the river front is suggested by way of Shaonis street, or by Paxton Creek. A suitable connection not included in the plan, could also be made on Twelfth street to the wooded slopes of Cameron Creek. This outlying drive system is outlined with the hope that it may be possible to at least control the trees and shrubs on either side of the travelled drive, for they are chiefly responsible for the beauty of such a road (ill. 33-34). INTERIOR WALKS AND DRIVES. Many citizens who most need the outing, will not go to the pub- lic reservations over narrow thoroughfares crowded with busi- ness traffic. Harrisburg is again fortunate in having several streets sufficiently broad to be given the character of a parkway, with turf, planting spaces, and uniform rows of trees. "It might be mentioned here that the successful planting of trees along all city streets, as well as along park approaches, can best be done by a park or other commission rather than by individual property owners. As Paxton street connects with a proposed parkway taking at the suggested small park, here there will be an opportunity to improve the street grade. From here it passes along the railroad bank, taking advantage of existing bridges, thence up the valley by THE FRONT. 85 a fine grove of trees, to a great circle at a junction with Market street and the park. The proposed parkway continues from a similar circle at State street and the park, along the valley back of the Arsenal (ill. 35), thence along the Asylum Creek slope, where it will be so screened by trees on the bluff as to be shut out from all view of the Asylum buildings. Through the bluff taking west of Paxton Creek, a road con- nection can be provided between State and Maclay streets, but from State to Paxton streets hardly more than paths and small playgrounds can be provided. THE FRONT. Quite as important as any of the thoroughfares referred to is Front street, which bounds the great landscape of the river that will be greatly improved if the dam, referred to in Mr. Fuertes' report, is built to hold the water at a fixed level at all times. Here also is the opportunity to establish a splendid esplanade, with gar- dens, playgrounds, promenades, and colonnades ; however, this must be the work of the future, or the monument of some gener- ous citizen. Some work, nevertheless, should be done along the water front to give the banks and streets a more finished appear- ance than they now have (ill. 36). The trees should be thinned and trimmed, and a good turf established. A clearly defined promenade should be made along the top of the blufl, with occa- sional cross-walks, and a hedge (ill. 37-38) planted along the top of the blufif to separate the finished condition of the street from the wilder covering of trees and shrubs upon the slopes. This will greatly improve the appearance of the street, and the expense will be so small that adjoining property owners might well afford to undertake it. The existing growth upon the banks should be encouraged and protected (ill. 39-40), for with a little judicious removal the un- desirable growth that shuts out the view (ill. 41-42), it will be quite as satisfactory and much more secure than any artificial planting could be made. CONSTRUCTION. The city does not need, and cannot afford, now, during the ac- quirement of land, broad parkways with several roads and paths through its reservations. It should at first provide very simple and inexpensive roads and paths, which, however, should be very 86 PROPOSED MUNICIPAL IMPROVEMENTS. carefully studied in regard to location and grade, in order tliat everything done will tend towards the completion of a definite plan. Without a study of detail plans, work is sure to be done that must be undone or remain unsatisfactory, especially where the margin for variation is small, as in some of the proposed tak- ings. Above all else, the mistake of clearing out the undergrowth in woods, or the shrubs in fields and along walls, should be avoided. What has been said regarding the desirability of opening reser- vations promptly to the public by simple means, applies with even greater force to playgrounds. A very simple and inexpensive equipment will appeal to the children quite as much as more highly furnished appliances. The plan provides a place for such grounds at the bluffs, and along the river shores, and it is further suggested that church and school grounds, especially in thickly settled districts, be opened. The educational value of parks must not be overlooked. In Wetzel's Swamp the native animals and birds could be introduced, protected and studied. The native flora of the entire system is a rich and interesting one, and the various species of plants could be designated for the benefit of students. In the artificial planta- tions required at Reservoir Park all exotics in common cultivation could be introduced in such a way as to be of real educational value. ACREAGE AND COST. Mr. G. A. Parker, of Hartford, Conn., after an exhaustive ex- amination of the statistics of American parks, presented the fol- lowing conclusions before the American Park and Outdoor Asso- ciation at its last annual meeting. "One-twentieth of a city's area should be preserved for parks and squares." The plan shows within the city limits takings, which, together with the Reservoir Park additions, include one- tenth of the total acreage. Mr. Parker further states "there should not be less than one acre of park land to two hundred of popula- tion." The same takings referred to above, but with the popula- tion about Reservoir Park excluded, provide one and eighteen- hundredths acres per 200 people. With the addition of Wetzel's Swamp there would be one acre to sixty-five population, but here again we exclude the population beyond the city limits. With this same exclusion the cost per capita would be about ten dollars. PROBABLE COST — LAND TAKINGS. 87 Reliable figures of per capita cost in cities of the size of Harris- burg are not available, but for the most larger cities the cost has been higher than this. Nine hundred and twenty-nine acres are represented on the takings plan, with an assessed value of three hundred and eight thousand dollars, this being sixty per cent, of the real value, five hundred and thirteen thousand, four hundred dollars. The estimated cost of inexpensive roads, paths, drainage and bridges, to open up reservations and equip playgrounds, brings the amount up to five hundred and fifty thousand dollars. The population of the city is fifty thousand, as against about thirty- nine thousand in 1890, and the area is about three thousand acres, within which, and including Reservoir Park, the plan shows tak- ings of three hundred acres. The estimated cost is believed to be high. It includes a por- tion of the Asylum and Arsenal property, which presumably, could be secured from the State, also river frontage, some of which, we are led to believe, will be transferred to the city. The assessors in the Wetzel Swamp district make no distinction between the upland and the swamp. Here the estimate is based upon the average values of whole farms. Furthermore, it is expected that much blufif and land for boulevards may be donated by owners, as in other cities. A parkway increases land values considerably, ow- ing to the assurance of permanently attractive surroundings and a more agreeable means of communication. About Reservoir Park a striking example is presented of the increase in land values. At the time this park was established in 1889, lands were valued at two to three hundred dollars per acre, while the average now is seven hundred and fifty dollars per acre. ACQUIREMENT OE LAND. Apparently your State laws make ample provision for the in- auguration of a movement to acquire a park system and play- grounds. Act 257 of 1895 and its amendment 154 of 1901, allows cities to acquire land for park purposes outside of the city Hmits and re- quires the annexation of the same. Act 239 of 1901 provides for the appointment by the Court of Common Pleas of five citizens, not officials or city employes, as trustees, to have authority over lands given to the city for park purposes. Act 245 of 1895 provides that city school boards may permit 88 PROPOSED MUNICIPAL IMPROVEMENTS. the use of school grounds for recreation purposes and arrange for the care of the same. The act also permits the city to arrange with individuals or associations for the use of their property as park reservations, and make all necessary expenditures. Act of 1901 authorizes the city council to appoint a commission for the direction of such pubhc affairs. If you can take advantage of Act 239 of 1901, such a commis- sion should be appointed to secure gifts of lands included within the takings from public spirited citizens. A citizen could estab- lish no more permanent monument than a gift of land to enhance the beauty of the city and give health and pleasure to its citizens. A warning, must be given, however, against the indiscriminating acceptance of gifts, especially gifts of land for parkways or boule- vards outside of the Hmits established in a consistent plan. Even upon such boulevards it would be better for the park authorities to be responsible for the care of plantations and grass plots, leav- ing the maintenance of roads and walk surfaces to the authorities who care for roads. It is only within the parks themselves that roads should be constructed and be maintained by park authorities. CONTROL OE PARKS. In acquiring and developing a great public park having all the elements of a beautiful landscape, a city is creating and preserving a gallery of living pictures. Whether these pictures are to grow continuously in beauty from year to year and from century tp cen- tury, or be disfigured or seriously injured, is wholly dependent upon the original design of the system and its future maintainance. A park designer must not only have the ability to perceive the greatest beauty that lies within the crude landscape, just as a sculp- tor sees the beauty in his crude stone, but also the technical knowledge to carve it out, or make it grow up to his ideal. He must provide at all times for all the requirements of the public in such a manner as to not defeat the main purpose. These pictures are alive, and to grow in beauty they must be cared for by persons who are in sympathy with the motives of the designer and whose term of office and that of his principal assistants is a permanent* one. The most important American park systems have been inaugur- ated by public spirited citizens who have given their time freely during their development. In later years, however, the control of such systems drifts into the care of paid boards of city offi- cials. If you are to secure the best results the undertaking must ^ « 0' £ c 09 M ^ So n.- M u ^ is 1^ >, Run pper valle t "g S £ *F«i t^ . I- a _ ^ /er front nea on Marshal ige in Paxto GENEEAL CITY IMPROVEMENTS. 89 always be controlled by citizens who can appreciate fully all the purposes for which public reservations are acquired. GENERAL CITY IMPROVEMENTS. I will close this report by referring very briefly to the work that individuals, firms and corporations are doing to make the city a more agreeable place to live in. The office buildings in the very heart of the great Bailey RoUing Mills, one covered with a lux- uriant growth of vines and shaded by a vigorous tree (ill. 43), the other surrounded by flower beds and with groups of trees (ill. 44), so disposed as to screen a great bare building from view, show that it is only necessary to extend planting operations of this character to relieve a great manufacturing plant from all its bare- ness (ill. 46-47). Occasional individual trees in this establishment (ill. 48) and elsewhere (ill. 49-50-51-52), show how much can be hidden by a towering mass of foliage which is supported by a stem, only occu- pying but a few feet, and requiring but little care as compared with "beds of expensive, tender plants, that require yearly renewal (ill. 53). That it is not necessary to go to the expense of rich soil is made evident by the growth that you will find established in noth- ing but cinders (ill. 54-55). A little encouragement to tenants will soon transform untidy "back yards to pleasant garden spots (ill. 56). The work that individuals are doing to make their homes as well as the city attractive, is well illustrated all over the city in the use of vines (ill. 57-58-59), window boxes (ill. 60) and flowers {ill. 61). How important street trees are in making the city more attractive is well illustrated by the two sides of Broad street in looking from Front street to the river (ill. 61-62). It is this kind of civic improvement that should be encouraged by joining hands with such associations as the Civic Club, by aiding the formation of local improvement associations, and above all by enlisting the aid of the press. WARREN H. MANNING. September 16, ipoi. APPENDIX. ACREAGE AND ESTIMATED COST OF LAND. Acreage and cost of land to be used for the proposed Harrisburg park sys- tem, values based upon averages taken from the assessed value of the land, which may be considered to be about 60 per cent, of its real value. 90 PROPOSED MUNICIPAL IMPROVEMENTS. The takings have been divided into River Frontage, Valley Land, Bluffs, and Uplands. RIVER FRONTAGE. Maclay Street, north 34 acres at $300 $10,300 00 Maclay to South Street 14.6 " 500 7,300 00 Paxton Street, south 7 " 500 3,500 00 55.6 $31,000 00 VALLEY LAND. Wetzel Swamp Land 465.38 acres at 150 63,793 00 Mill District walk to river 3.3 " 1000 23,300 00 Along Paxton Creek 10 " 490 4,900 00 Canal, Maclay to State St 15.5 " 490 7,595 00 Total 493.08 acres $84,587 00 BLUFFS. Maclay Street, north 110.4 acres at 300 33,080 00 Muench to Hanover Street 73.75 " 800 59,000 00 184.15 81,080 00 UPLANDS. Land Above Wetzel's Swamp 19.5 acres at 300 5,850 00 "Spur" leading to the Reservoir, via Arsenal 19.0 " 350 6,650 00 " Spur " to same, via R. R 73.1 " 500 30,050 00 Reservoir District 86.5 " 750 64,875 00 Total 197.1 $113,435 00 Total acreage, 939.93. Total cost according to assessed value, $300,093.00. Assessed value, 60%. Real value, $500,153.0^, Asylum Property 31.7 acres at 350 7,595 00 Arsenal Property 1. " 350 350 00 $7,945 00 ESTIMATED COST OF DRIVES AND WALKS, CONSIDERING THEM TO BE TEMPORARY CONSTRUCTIONS. Drives 15-30 ft, 63,760 ft. at 50 cents per ft $31,380 00 Paths 6-8 ft, 35,608 ft. at 30 cents per foot 6,683 40 30 Playgrounds at about $500 each $10,000 00 Plans, etc, for Playgrounds 1,785 00 REPORT ON STREET PAVING FOR HARRIS- BURG, PENNSYLVANIA. Newark, N. J., September i6, ipoi. Executive Committee on Plan for Municipal Improvements, Harrisburg, Pennsylvania. Gentlemen: — I would respectfully submit for your considera- tion the following report or suggestions, with forms of specifica- tions, proposed cross-sections, and details for pavements for your city. For ease of traction, comfort and wealth, good roads and well paved streets, which will sustain the traffic and may easily be kept clean, are a necessary adjunct to good government. Combined with well constructed pavements, a good general appearance and finished look to the work should be obtained. Scarcely any other form of city government is as apt to impress the stranger visiting your city as the condition of your streets. This fact, together with the obtaining of the comfort, convenience and health of your own citizens, and the making of your city a more attractive place in which to live, should prove an incentive for more and better paved streets. Too little attention is usually paid to details in connection with street work, generally because the cost of well-dressed and well-set curb stones, and substantial and neat catch-basin inlets is con- sidered too expensive. When these expenses are divided over the entire work, and when the lasting quality of substantial work is considered, the result obtained fully justifies the additional ex- penditure, which after all, is only a shght percentage of the entire cost. For the above reasons, in addition to the general require- ments for good pavements, I have touched on such details as I trust may prove of use in your work. KINDS OF PAVEMENTS. The history and development of pavements as at present laid has been slow, and although the method of modern construction for city and suburban use is well defined for the various kinds of pavements, still it can hardly be said that the ideal pavement has; 92 PROPOSED MUNICIPAI^ IMPROVEMENTS. yet been reached. I have not attempted to describe the steps through which the development of the several classes of pavements have reached their present reasonably well prescribed methods of construction, but shall attempt to define the present practice in regard to the laying of the classes of pavements which I think suited for your various conditions. The selection of the kind of pavement to be used for the various streets must depend largely upon local conditions and upon the use to which such streets are likely to be put in the immediate future or during the life of the pavement. Let us start with the conditions which must be common for all pavements, namely, that the sub-grade must be properly prepared, and should in all cases be rolled with a heavy steam roller, and all soft and spongy places dug out and refilled with gravel or suitable soil which may be firmly compacted by the roller. The next consideration for the pavement proper must be to give a foundation of sufficient stability to sustain the load to be carried on the surface and must be of sufficient thickness to dis- tribute this load upon the sub-grade over such an area as not to cause a depression in its surface. The selection of this foundation should depend somewhat upon the nature of the soil and the conditions of the under drainage of the street upon which it is to be laid. By this, I mean for streets where the entire sub-grade is gravel or of a sandy nature, it is not essential particularly for light traffic and for such pavements as granite block for instance, to lay an expensive foundation. The coating, covering or wearing surface of the pavement proper to be spread upon this foundation, should again be selected with a due regard to the nature of the traffic to be borne by the pavement as a whole. It should be impervious to water, not only to permit of its cleanliness, but to prevent injury to the foundation and sub-grade. It should be smooth (except on steep hills), to facilitate ease of traction. It should be durable to reduce cost of repairs, and should be easily repaired when the same is necessary. Its cost should be proportional to the traffic that it is to sustain. It is essential, therefore, that the selection of the material for this wearing surface must also depend upon the local conditions and the probable use of the street. I have looked over your streets carefully in company with your City Engineer and the Secretary of your League, and have noticed the nature of the traffic and present use of most of your principal PAVEMENT REOOMMENDATIONS. 93 streets. After considering these inspections and the class of pave- ments now laid, I would recommend the following kinds of pave- ments for use in your City and have endeavored to pick out typical streets upon which, in my judgment, such pavements could be laid to advantage: Macadam pavement for Front street, or such purely resi- dential streets as are not likely to ever become in any sense busi- ness streets, or upon which trolley lines do not now exist or are not likely to be laid. It might be advisable to lay a few blocks of this street in the centre of the city south of Walnut street with a more substantial pavement. From Walnut to North street, I would recommend macadam pavement twelve (12) inches deep, and from there north eight (8) inches macadam pavement. The curb line to be moved out from seven (7) to ten (10) feet on the east side where the same can be done and still give sufficient road- way. This space between the sidewalk line and the new curb line should be devoted to grass plots, as shown in one of the accom- panying sketches. Granite Block pavement on a sand foundation, or even on concrete in some cases where the sub-soil is naturally springy; for such streets as Race street (given as an example, though now paved with brick), where the traffic is very much congested and confined to a narrow space. Granite block is the most economical pavement in the long run for such locations. It also seems advis- able, from the experience in other cities, that at some future date, should the traffic from factories, warehouses, etc., to the freight stations warrant it, that some through street running north and south should be paved with a granite block pavement to give one street which will be durable and at the same time serviceable in all kinds of weather. Asphalt pavement on a concrete base for your business streets, such as Market Street, as now laid, and as may be selected for your semi-business and residential streets where the grade does not exceed five feet in one hundred. It is not, however, well to lay asphalt on streets that have an exceptionally light traffic, as this pavement needs a moderate amount of traffic to insure its life. It has also been found expedient not to lay too many consecutively parallel streets with asphalt on account of its slippery condition for days at a time during the winter. Brick pavement on a concrete foundation for such streets as Mulberry and State streets, at least for the steep parts of such 94 PROPOSED MUNICIPAL IMPROVEMENTS. streets, as well as for the purely residential streets and those of a semi-business nature. In many cities the selection of either brick or asphalt for rea- sonably level streets is generally one of local choice, and the com- bination of two kinds of pavement on the same street is often found. That is, the steeper parts being paved with brick, generally selecting a brick with a rounded edge for the portion of the street having the heavy grade. A combination of these two pavements might prove of advantage for such streets as Thirteenth and Derry streets. These two streets will always be more or less thorough- fares and business streets, and I would not advise the use of macadam on them for this reason and for the further reason that it is not well to use macadam where there are street car tracks. Where streets like the above exist which have already been more or less macadamized, it has sometimes been of advantage to use the macadam existing on the street in the preparation of the foun- dation for a more improved pavement. A good foundation for either brick or asphalt may be made by taking up the old macadam, carefully cleaning it, relaying on a new sub-grade, rolling it thor- oughly and washing in sand until all the interstices are full. Such foundation is slightly cheaper than concrete, but if the pavement is to be more or less disturbed by cutting for house services, it is always more difficult to replace the foundation satisfactorily than where concrete is used. In addition to the above suggested pavements, many other forms or combinations of different materials have been suggested for street work, some of which have proved more or less of a suc- cess. I will mention some of these, stating why I have not recom- mended their use, though I do not wish to be understood as con- tending that they cannot be successfully used. Tar Macadam. — A pavement made of a mixture of macadam foundation with a top dressing of tar and small broken stones mixed together, spread and rolled into the macadam. This pave- ment is more or less of an experiment. It has given fairly good results, certainly better than plain macadam, but good results de- pend almost entirely upon the quality of the tar, which is a pro- duct very difficult to obtain of a uniform standard. The cost is much more than for macadam pavement, and when its durability and maintenance is compared with asphalt, the cost is about equal to the latter. Since tar macadam is not extensively laid by organ- CONSTRUCTION. 95 ized companies, as is the case with asphalt, guarantees for. its durability are not as reliable. Wooden Block Pavement. — Some forms of wooden block pavements composed of strong creosoted wood in blocks similar to bricks and laid on a concrete foundation in somewhat the same manner as brick pavement is laid, are being tried in several cities. The pavements of this kind which I have seen that were substantial, have cost much more per square yard than asphalt; they were less noisy than asphalt or brick; not as im- pervious to water, and while on the whole, when thus laid, they give a good street, I do not consider their construction sufficiently well advanced or established to recommend their use. Asphaltic Block, when well laid, has given satisfactory re- sults. I believe, however, that it should only be laid on such grades as will entirely prevent water from standing on the pave- ment at any point. You have some fairly good examples of this class of pavement, but my experience has shown that whenever a slight depression exists which holds water for any length of time, the blocks at this point begin to disintegrate. GENERAL CROSS-SECTION EOR PAVEMENTS. In general, the slope of the cross section for granite, asphalt and brick pavements should be one foot in forty or fifty feet. That is, a street forty feet between curbs should show a six-inch gutter on each side, with the centre of the street level with the top of the curbs, and the distance at the quarters measured down from a line between the top of the curbs should be one-quarter of the depth of the gutter or one and one-half inches. This gives a comparatively level space in the center of the street for traffic, and a fall of four and one-half inches from one-quarter roadway into the gutter. These measurements are shown on the accom- panying cross sections for the different width of streets. For purely residential streets, nearly all cities have adopted narrowing the roadway when the streets are paved, and a thirty-foot road- way is found sufficient even for streets sixty feet in width where former roadways have been thirty-six to forty feet. I believe that in many cases, particularly where street car tracks are not likely to be laid, that even twenty-eight feet between curbs will be found sufficient width. This narrowing of the roadway will not only re- duce the cost of pavements per running foot, but will allow the new curbs to be set on uniform lines without interfering with trees 96 PROPOSI^D MUNICIPAL improvem:ents. and other permanent fixtures along the sidewalk, and will at the same time allow space for grass plots in front of each lot, which if systematically cared for materially enhances the appearance of the street. On hill streets, or as the grade increases above three feet in one hundred, the cross section of the street can be considerably flattened to advantage by dropping the centre of the street from one inch to two inches below the top of the curb for a forty-foot street. For macadam pavement, the cross section should be somewhat steeper, particularly where much water is carried in the gutters, and also on steep grades where the water should be confined to the gutters as much as possible. Gutters of stone or brick should be laid in connection with all macadam pavements, as the wash of the water is particularly injurious to this class of pavement. Some cities, noticeably Washington, D. C, have adopted brick gutters to be used in conjunction with asphalt pavements, especi- ally on flat grades where slight inequality in the surface of the as- phalt is apt to allow water to stand on the pavement, causing disin- tegration to take place. Where sufficient grade (over three inches in one hundred feet) can be obtained in your gutters such precau- tion is hardly necessary, and as I understand from your City Engineer that this grade can invariably be obtained, I have not shown this style of construction. When a brick gutter is used in connection with asphalt pavements it should extend about three and one-half feet from the curb, and should be composed of regu- lar street paving bricks laid to the same cross section as for the asphalt pavement with the joints carefully grouted with Portland cement. CURB-STONE. I have shown in the details and cross sections of streets here- with submitted, blue-stone curb-stone five inches thick, twenty inches deep, with face dressed down ten inches for the portion which shows above the pavements, and the back dressed down four inches where the flagstone for the walks may be laid against it. I have found uniform curb stone of this dimension is one that may be readily obtained in the market and can be relied upon for good appearance, and substantial results. Such a curb if used uniformly on your work, would, I believe, materially enhance the appearance of your streets. A well-dressed granite curb of some- what less depth set on concrete may be used to advantage. It CAR-TJRACK PROBI^EMS. 97 would no doubt cost more than blue stone, and I doubt if results would be any more satisfactory. I have noticed, and your City Engineer has called my attention to the use of steel angles for curb-stone and these certainly have given good results where used in a number of places. I have no doubt that a special form of angle rolled for this purpose might be advantageously used, but doubt very much whether these angles could be obtained and set for as low a price as blue stone. On improved pavements I be- lieve that it would be poHcy to set the curb-stone on concrete, as shown in the accompanying sketches. This would take about one cubic foot of concrete per running foot of curb, and the depth of the curb stone could be made sixteen inches instead of twenty. STREET-CAR TRACK CONSTRUCTION. The difficulty of maintaining pavements adjoining street-car tracks has been a source of constant trouble in all cities. The traffic constantly following the rail and giving undue wear to the longitudinal joint between the rail and the pavement, combined with a movement of the track due to a yielding substructure and the heavy electric cars which are now in use, all tend to require much care in the method of laying tracks and pavements adjoining them. Many cities have adopted the laying of granite blocks and sometimes brick in a header and toothing course along the rail in conjunction with asphalt pavements, but these blocks or bricks often become displaced due to the movement of the rail, or the line of wear is moved out to the joint between the pavement and the blocks or bricks. The first requisite to obtain good results in lay- ing pavements along street car tracks is to have substantial and firm track construction, which will be rigid and prevent the breaking of the bond between the pavement and the rail. When the work is thus constructed, I would recommend that the pave- ment adjoining the track be carried directly to the rail both inside and outside the track. I have shown in the sketches a method of laying the street car tracks on a beam of concrete, using iron ties and iron tie rods, these being also laid in concrete. This is prac- tically the construction used by the Harrisburg Traction Company on Market street, and I understand is approved by them, and would, I believe, be laid by the Company upon all streets which have tracks upon which improved pavements are laid. This con- struction would be cheaper in the long run for the Traction Com- pany, and certainly add to the life of the pavement and reduce the 98 PROPOSED MUNICIPAI, IMPROVEMENTS. cost for repairs. I would recommend its use in connection with all pavements having concrete base. In connection with street-car tracks it is aLso advisable to pro- vide a catch basin for surface water between the rails of each track where a pocket or a change from descending to ascending grade occurs in the street. Such catch basin to be connected with the street catch basin or sewer and covered with an iron grating extending from rail to rail and set on a level with the tread of the rail and slightly below the pavement grade. CATCH BASINS AND DETAILS. An important part of paving construction is the way catch basins or storm water inlets to the sewers or drains are constructed. I have devoted one of the accompanying plates to this work. A catch basin with a six-inch stone cap and a substantial arrange- ment of the trap and inlet is shown. Although these basins are somewhat more expensive than those with iron top and inlet, I would recommend their use for your permanent construction as giving a more substantial and certainly a more finished appear- ance to the street work. I have also on the same plate a method of notching the curb under the cast iron inlets to take the place of the brick work, which is often allowed to appear on the curb line. Much complaint is often caused by the rattling of loose manhole covers, and in laying pavements care should be taken to see that manhole covers fit closely so as not to rattle, or be provided with a lead seat on the frame ; these covers give a dull thud instead of the metallic ring of iron to iron. Some cities have also found it advisable, in laying asphalt, to use a special manhole cover having an asphalt top. These refinements in regard to the sewer connections should, I think, be considered part of the cost of the pavement. Some cities do not include this kind of work with their paving contracts, but I would recommend that it should be done, as it assures the simul- taneous completion of the work under one contract, and, as they are in a sense essentials to the pavement, the cost should properly be assessed with this work. On one of the accompanying plates is shown, in cross section, a plan for the treating of side hill streets or those streets on which the gutter on one side of the street is much higher than on the other. After streets of this character have become extensively built upon and sidewalks and other permanent appurtenances sub- GBJSrERAI, REMARKS. gg stantially constructed, a material change in the grade of the walk invariably works a hardship on some of the property owners. When the width of the street admits of the narrowing of the road- way, the curb of the high side of the street can be moved out to a greater degree than the curb on the low side, in the proportion of five (5) feet on one side to three (3) feet on the other, for instance. The change is so slight that the ordinary observer will not notice that the roadway is not symmetrical with regard to the centre line of the street. This arrangement allows terraces to be constructed on the high side of the street and the new curb lines can thus be set practically on the same level, after which the usual cross sec- tion for the pavement can be constructed and the space added to the sidewalks converted into grass plots as before suggested. GENERAL DISCUSSION OE THE SEVERAL KINDS OE PAVEMENTS RECOM- MENDED. As has been before stated, the ideal pavement for street use has not yet been found, and there are a number of objections to each of the several kinds of pavements heretofore recommended. Some of these objections to a greater or less degree may be obviated either in the construction or the care of the streets. Macadam pavements are short lived at the best and need constant and systematic re- pairs. These repairs should be made practically in the same way in which the pavement was constructed, the old surface being gone over carefully with a pick to allow the new stones to bind in with the old, and finer stones should be used in making the top, all being rolled together as the work proceeds. Local limestone can be used to advantage for the bottom courses, but the top dressing should be of some hard material, and for the neighbor- hood of Harrisburg, I would suggest that some of the local hard stones be tried for the top dressing. Near New York city trap rock is invariably used for the top dressing even when the foun- dation is of limestone, and the increased life of the pavement often warrants the use of a hard stone for the top dressing even when necessary to transport it for long distances. It is essential for the life of a macadam pavement that it should be kept in good cross section to drain the water from the surface into the gutters in stormy weather, and also that it should be con- stantly sprinkled in dry weather to prevent the clouds of dust which arise from a neglected pavement of this character. Both of these precautions will add to the life of a macadam pavement, but lOO PROPOSED MUNICIPAL IMPROVEMENTS. for city streets the laying of macadam is hardly to be recom- mended, and its use should be confined to those streets used almost exclusively for pleasure driving and park roadways. Granite block, though the most durable pavement, is very ob- jectionable on account of its rough surface and the noise resulting from its use. It is also difficult to keep this pavement clean. Its use should be confined exclusively to business or manufacturing districts, or where exceptionally heavy traffic is confined to narrow limits. Asphalt pavement, when properly laid, is no doubt the most satisfactory pavement for city streets. It should also be kept scrupulously clean. The street filth being ground to fine powder upon its surface is particularly objectionable and penetrates into all crevices. Constant sprinkling and the use of much water on asphalt streets not only affects the life of the pavement, but forms a sticky paste which is very objectionable. Many cities have found it advantageous to thoroughly flush asphalt streets at night, or systematically care for them by the constant attention of a man to a section, the length of section depending upon the amount of traffic. In laying brick pavements, the best method of filling the joints has been a mooted question. Sand, tar, and cement grout are used as fillers. Brick pavements laid with cement filler are much more durable than those laid with a less rigid filler. It has, however, been found in several cities that brick pavements so laid some- times cause a roaring or rumbling noise as the wheels of wagons roll over them. An engineer in one of these cities suggests that if the pavement is laid during the warm weather after the concrete is thoroughly set, and care is taken to have the bricks thoroughly rolled and bedded in the sand, there should be no trouble from abnormal noise. In connection with the cement filler, four or five tar joints across the street at distances of about fifty feet apart along the street have been used to advantage to allow for expansion and contraction of the pavement. The better qualities of brick now made for pavement purposes make a very substantial pavement. In the specifications which follow, explicit methods of testing brick are suggested. The test for abrasion, however, is a difficult one to describe without com- parative tests being made to determine the percentage of loss to SPECIIflCATlON'S. lOI be allowed in the rattler or tumbling barrel. The abrasion test given in the specifications is thoroughly representative of what such test should be. It might, however, be found advisable to increase or decrease the allowable percentage of loss after experi- ments are made, as suggested. In connection with the laying of any of the pavements sug- gested, it is self-evident that to obtain uniformity in the appearance of the street, the existing basket gutters made of brick, cement, etc., must be sacrificed to the new work. Even where macadam roads may be laid, I would recommend that these gutters be done away with and curb substituted unless it is possible that entire blocks of uniform gutter might be adapted to the new macadam work. The following suggestions in regard to specifications are given as guides to cover the important parts which should be considered in the construction of the various kinds of pavements. Some of the clauses are of course general in their character and will be appHcable for all of the pavements mentioned. Many of the re- quirements given are compiled from the best practice of the pres- ent day in our most progressive cities. SPECIFICATIONS GENERAL CLAUSES To be included in the specifications for the several kinds of pavements when applicable. Clearing of street. — Should there be any curb, rubbish or other incum- brance on the line of the work at the time stipulated for the commence- ment of the same, it shall be removed by the contractor at his own ex- pense; also all trees, stumps, roots or other obstructions which may interfere with the alignment of the curb, as fixed by the Engineer. Resetting basin-heads, etc. — All basin-heads and sills, manholes and lamp- hole frames or heads must be reset to the proper grade and in a work- manlike manner; hydraulic cement mortar, as is made for the concrete mixture, must be used in the alteration of the brick work. The contractor will receive no allowance for this work. Readjusting old curb, etc. — All water and gas stop-cocks and manhole frames or heads over underground conduits will be reset by the parties who own or control the respective appurtenances, to the approximate grade, but the final adjustment to the finished grade of the pavement must be done by the contractor without extra allowance for the same. The old curb and bridge stone which may be retained shall be readjusted to the new grade; and if directed the old pavement in intersections; and I02 PROPOSED MUNICIPAL IMPROVfiMENTS. SO much of the pavement in adjoining streets, either between curbs or only in the gutters, as may be necessary to obtain proper drainage. Old and new curb. — Such old curb stone on the line of the work as may be ordered retained must be redressed and reset, otherwise new curb stone must be set in place. The new curb stone must be equal to the best quality of North River blue-stone, hard, sound and free from seams or other imperfections; it must be five (5) inches on top, twenty (20) inches deep (unless ordered of a less depth when set on concrete) and not less than four (4) feet in length. Its thickness for ten (10) inches down from the top must be not less than that of the top. The back shall have no projections of more than two (2) inches, while it must have a uniform thickness for at least four (4) inches down from the top. The top and face for ten (10) inches must be dressed and be at least equal to six cut work. The bottom must be roughly squared, and in no case be less than three (3) inches thick. The top must be smooth and have a bevel of three-eighths (%) inch for the thickness of the curb; the face shall in no place vary more than one-eighth (Vs) of an inch from a true plane for ten (10) inches down from the top; and shall have a batter or slope of one (i) inch for twenty- inch curb, and of three-quarters (%) inch for sixteen-inch curb. Old curb which is retained must be redressed to conform in appearance with the new curb, and the top of such curb must be cut to a uniform thickness as far as practicable. Alignment of curb. — The front of the curb, when set, must present a fair and unbroken line; and the grade correspond with that given by the Engineer. Curb corners. — All curb-stone for new corners must be cut to a radius of five (s) feet, unless otherwise directed, with true and radical joints, and of the same quality as the straight curb, and set in like manner. No extra allowance will be made for special radius. The resetting of old corners will be allowed for at the same price as for resetting straight curb. Curb set in concrete. — ^When called for, all curb stone, including corners, must be set in a bed of hydraulic cement concrete thirteen (13) inches in width and six (6) inches in depth under the curb, at least four (4) Inches in thickness behind, and extending ten (10) inches up from the bottom of the curb; all concrete must be thoroughly compacted by ramming. The average amount of the concrete for bedding the curb is to be one (i) cubic foot for each lineal foot. When the new pavement adjoins an alley or private driveway crossing the sidewalk, the curb stone must be dropped to within one inch of the finished pavement. While setting the curb, the top must be protected by a plank and then settled firmly into place by the use of a heavy rammer on top of plank. The loose soil around the curb must also be firmly compacted. Relaying flagstone.— K\\ fiag-stone on the sidewalks at the crosswalk ap- proaches, which must be temporarily removed to readjust or set the curb, must be trimmed and properly relaid, on a bed of sand, without compen- sation. SPiEClFlCATlON'S. 103 Damage to be made good. — If any flagstones are broken or damage done to other property, by storing any material for the work upon the sidewalk, the contractor must replace the broken stones with new ones, and com- pensate for other damages before the final estimate is made by the Engi- neer. If the contractor fails to make a final settlement, then the Engineer shall deduct the estimated cost of such damages from the amount due the contractor upon his final estimate. , New bridge stone. — New bridge stones when ordered for cross-walks must be equal to the best quality of North River blue-stone, hard and sound, and free from seams or other imperfections, they must be two (2) feet wide, not less than four (4) feet nor more than seven (7) feet long, and not less than five (s) inches thick. The bridge stone must be smooth on the top, and the sides and ends shall be cut square, so as to form close joints from top to bottom; if any of the side faces are under-cut or feather-edged the bridge stone will be rejected. The ends must be cut on a bias of six (6) inches in two feet if called for. The bridge stone is to be thoroughly bedded in sand not less than four (4) inches deep; and have its surface one-half (Va) of an inch above the general elevation of the pavement. They must be so laid, that the trans- verse joints will be broken by a lap of at least one foot. Old bridge stone. — The old bridge stone that is ordered to be relaid must be redressed in the same manner. Bridge stone on concrete. — When a concrete foundation is laid under the new pavement, the old and new bridge stones must also be laid upon such a foundation, with a sand cushion of at least two (2) inches in depth over the concrete. Imperfect curb or bridge stone. — After the pavement is completed, if it is found that any of the new curb or bridge stone does not comply with the requirements of the specifications as to hardness, etc., then the contractor will have to take them up and put proper material in place. Paving blocks. — ^The contractor must lay two rows of stone blocks be- tween the course of bridge stone, where the same may be ordered laid in connection with granite block pavements. Old material. — ^The old curb and bridge stone, also the old paving ma- terial which are not retained upon the street, shall remain the property of the city unless otherwise provided for and shall be carted and stored by the contractor as may be specifically ordered. The contractor must remove at his own expense all such material with- in 24 hours after it is taken up from the line of work, and deliver it at the city yard or where designated. Preparing roadbed. — The subsoil or other matter shall be excavated and removed by the contractor to the depth of the subgrade of the proposed pavement. When a plough is used no ploughing below subgrade will be allowed and the final trimming shall be done by pick and shovel. The price per square yard for the pavement is to include all the necessary ex- cavation. Should there be any material or vegetable matter in the bed thus pre- pared, all such material shall be removed, and the space filled with clean I04 PROPOSED MUNICIPAIv IMPROVEMENTS. gravel or sand, carefully rammed or rolled, so as to make such filling com- pact and solid. Old trenches, how to be treated. — It there is a sewer, water or gas main, or any underground conduit in the street or avenue about to be paved, the contractor must, at his own expense, prepare the top of such trenches for their full width into an unyielding condition, also the trenches of the connections with the several mains, if necessary, by removing the loose material on the top to a depth of two feet from the bed for paving, and replacing the same or other material in layers of six inches, each of which is to be thoroughly rammed. New trenches. — The right is reserved to issue permits to construct any sewer, receiving basin and its culvert; to lay water or gas pipes, or any sub-way construction; and to make house connections with the several improvements; or to alter, and relay any railway tracks in advance of the contract work. The refilling of all these trenches will be done under the supervision and to the satisfaction of the city authorities. The contractor,, however, will be held responsible for any settlement of the pavement over any of the trenches, which were made previous to the commencement or during the progress of the work. Rolling- vf roadbed. — ^The entire road-bed is to be truly shaped and trim- med to the required grad^, and must be rolled with a steam roller weigh- ing not less than 5000 pounds per foot of width of roller, until the surface is firm and compact. If necessary to obtain a compact bed, the surface must be sprinkled with water before rolling. The roller on each trip must over-lap at least one-half the width of the surface that was compressed by the roller on the trip immediately preceding it. In the places where the roller cannot be used, the sub-grade must be thoroughly tamped or rammed. Any depressions, defects or settlements which appear after rolling or ramming, must be made good by the contractor, and again be rolled or rammed, as the case may require. Prepared surface not to be disturbed. — After the road-bed has been rolled and prepared for the laying of the pavement, no wagons or other vehicles which could disturb the finished surface will be permitted thereon, unless the road-bed is covered with planks. Distamce to be prepared.— Tht foundation must be thoroughly prepared between two cross-streets and all sub-soil and surplus material shall be removed. Upon the sub-grade will be laid either a bed of sand or gravel, or a bed of hydraulic cement concrete, as may be called for. Sand or gravel foundation. — The sand or gravel, when thoroughly dry, must be laid to a depth necessary to bring the pavement to the proper grade or crown; the sand or gravel must be sharp and clean, free from loam or other impurities, if it contains pebbles which are larger than one (1) inch in diameter, the sand or gravel must be screened or raked, so as to free it from all pebbles of such size. A sample of the sand or gravel, intended to be used, must be submitted for approval before it is brought upon the line of work. When a concrete foundation is called for, a bed of SPECIFICATIONS. 105 hydraulic cement concrete must be laid six (6) inches in thickness which is to be made as follows: Concrete, how made. — One measure of hydraulic cement and two (2) like measures of clean sharp sand (free from loam or other impurities) must be mixed dry with shovels (unless an improved mechanical mixer is allow- ed to be used) upon a suitable platform or in a box until the mixture has a uniform color, this mixture shall then be made into a mortar by the adding of the necessary amount of water; then shall be added five (5) like measures of broken stone thoroughly wet with water but not con- taining free water in the pile. The stone must be sound, of good quality, broken uniformly and must pass in their largest dimensions a two (2) inch ring, the whole mass is to be thoroughly turned over with shovels not less than four (4) times, or until the broken stone is completely incor- porated. The resulting concrete shall then be spread upon the sub-grade so as to give a thickness of six (6) inches when thoroughly rammed, and the ramming shall be continued until a slight surplus of mortar shows on the surface; if the size or the quantity of broken stone does not produce this result, then the quantity must be diminished. No concrete shall be used which has begun to set, and no such material must be added to the mixture of a new batch. When new concrete is to be connected with a section which is already laid and set, or partially set, then the edge of that section must be broken ofJ, freed from dust or dirt, and properly dampened. Great care must be taken to make the surface of the concrete exactly parallel to the finished pavement. Protection of concrete. — The concrete must be protected from the effects of the weather; it must be sprinkled in warm weather, between the hours of sunset and sunrise, if necessary or directed, or covered with a thin layer of sand, or both. All wheeling or carting over the concrete must be pre- vented until it is sufficiently set, and then only when it is covered with planks, laid for this purpose; at least thirty-six hours shall be allowed for the concrete to set. Watchmen and barriers against traffic at all hours of the day and night must be maintained at the contractor's expense. Cement.— T\i& cement must be equal to the best quality of freshly burned "Rosendale" cement; it must be submitted for inspection and testing at least ten (10) days before use. At no time during the progress of the work is the brand to be changed without consent and then only when sam- ples for tests were submitted. Only cement made by manufacturers of es- tablished reputation will be accepted, and before any cement will be allow- ed to be used, the brand and name of maker must be submitted and be approved. The cement shall be kept in good condition, protected from the weather and free from moisture until it is used. The barrels or bags containing the cement must be labeled or stamped with the name and brand and manufacturer. Cement tests.— Tht cement must be evenly ground, and when tested must at least meet the following requirements: Mixed neat; one day, in air until set, remainder of time in water, 80 pounds per square inch. I06 PROPOSED MUNICIPAI, IMPROVB.MENTS. Seven days, in air one day, remainder of time in water, 150 pounds per square inch. Mixed two of sand to one of cement; seven days, in air one day, re- mainder of time in water, 75 pounds per square inch. At least go per cent, by weight must pass No. 50 sieve having 2,500 meshes per sq. in. At least 75 per cent, by weight must pass No. 100 sieve having 10,000 meshes per sq. in. All cements shall meet such additional conventionally recognized re- quirements as to "hot water" set, and chemical tests as may be required. Broken stone. — The broken stone shall be of the best quality of hard lime- stone or other acceptable hard stone, entirely free from all dust or dirt or other objectionable matter, and broken to pass through a two (2) inch screen. Sand, detritus or any material other than angular fragments of stone retained by a half (%) inch mesh screen, will be considered foreign substances. The quantity and size of the smaller stone must be so gauged that they are just sufficient to fill the interstices between the larger stone. Side streets to be graded. — The contractor must also, without additional compensation regrade every highway which abuts or crosses the street under contract, for a reasonable distance back of the new pavement in order to make an easy approach, and leave no bumps or hollows. Removal of improper material. — It is hereby further agreed by and be- tween the said parties to this contract that all materials to be provided by the Contractor shall be of the best description and that if the said Con- tractor shall bring or cause to be brought on the said work any materials which do not strictly conform to the requirements of this contract, or the ordinances of the City of Harrisburg, the City Engineer shall have the right to order the same removed forthwith, and in case of the neglect or refusal of the said Contractor, or those employed by him, to remove such materials the said City Engineer may cause the same to be removed at the expense of the said Contractor and deduct the cost of such removal and all other expenses connected therewith from the amount which may be due to said Contractor on this contract. Engineer to determine quantity of work, etc. — And it is hereby further agreed by and between the said parties hereto that the City Engineer shall, in all cases, determine the amount or quantity of the work to be paid for under this contract, and the amount of compensation at contract prices to be paid therefrom, and further, that the said Engineer shall, in all cases, de- cide every question which may arise relating to the measurement of any work done under this contract, and his estimate and decision shall be final and conclusive. When inspectors are to be paid by contractor. — And the said party of the second part hereby agrees that if the time for the completion of the ac- tual work of laying and constructing said pavement under this contract shall be extended by the said party of the first part beyond the time named herein for said completion, the said party of the first part shall be fully authorized to, and may, deduct from the final estimate of the amount due to the said party of the second part of this contract, any sum or sums of money paid by said party of the first part to any person or persons acting SPECIiflCATlON'S. 107 as inspector or inspectors on the said work, as salaries or wages, after the expiration of the time specified in this contract for the completion of said work. Suspending work. — No damage can be claimed by the contractor on ac- count of the suspension of the work, but a corresponding extension of time for the completion of the work may be granted. When any suspension is ordered all the materials upon the line of work must be placed in a manner so as not to interfere with public travel. Approval of work. — ^The whole work is to be done and completed in a workmanlike manner, and to the satisfaction of the City Engineer. Additional penalty for not commencing and completing on time. — If the con- tract work is not commenced and fully completed according to the terms of the contract within the time herein limited for its performance, unless further time for the commencement and completion be granted to the con- tractor by the said party of the first part, the contractor shall forfeit and pay for each day that may elapse after the time so limited for its com- mencement and before its final and full completion the sum of three dol- lars per day, when the gross amount to be paid to the contractor shall be less than three thousand dollars, and two dollars per day additional for every two thousand dollars above that sum. Penalties to be deducted from payments for contract. — Where any penalty of forfeiture is imposed by the terms of this contract for the failure, neg- lect or default of the contractor in the performance of this contract, or where such penalty or forfeiture is imposed or declared by the laws of the State or the ordinances of the city, the amount of every such penalty or forfeiture, when incurred by the contractor, may be deducted and with- held from any money due or to become due upon this contract, and when so deducted and withheld shall be deemed and taken as payment to that extent. Contract not to be sub-let. — ^The contractor will not be allowed to sub-let the whole or any part of his work, or make an assignment of the contract or of the moneys to be paid to him thereon, without special permission in writing from the Board or City ofiEicer having charge of this partic- ular work. Responsibility of contractor. — All loss or damage arising out of the nature of the work to be executed, either from accidents, the action of the ele- ments, the encumbrances on the line of the work, from improper protec- tion or from any cause whatsoever, must be sustained by the contractor. Employment of labor. — The contractor shall employ local labor so far as practicable, and in all cases local labor, either skilled or common, shall have preference, other things being equal. The men to be employed by the contractor must be thoroughly skilled in their work, and if any person employed shall appear incompetent or disorderly, he shall be immediately discharged upon the demand of the Engineer and such person shall not again be employed. Inspection.— The: work will be done under the supervision of an inspector or inspectors, whose duties will be to see that the requirements of the specifications are carried out; but their presence is in no manner to be Io8 PROPOSED MUNICIPAL IMPROVEMENTS. presumed to relieve in any degree the responsibility or obligation of the contractor. Imperfect w;or&.— When any of the work is found to be imperfect or con- trary to the specifications, whether it was passed by the inspector or not, the work must be replaced by such that is satisfactory. Suspending and resuming work. — ^The contractor shall suspend all work when notified by the Engineer that the weather is unsiutable to carry it on. If work is allowed during cold or freezing weather, the contractor shall take such additional precautions as the Engineer may require, with- out additional cost. Under no circumstances shall materials be used which have been affected by the weather. Clauses giving the estimated quantities of the amount of work to be done and upon which the bids are to be compared, also specific statement of the items upon which prices are to be given in the proposals, should be added to the specifications for each piece of work. The method and time when payments will be made to the contractor should also be clearly set-forth. SPECIFICATIONS FOR MACADAM PAVfiMEl^TS. By the term macadam pavement as previously used in this report, it was intended to include broken stone pavements whether a uniform size of stone was used for the foundation, or larger irregular stones, placed by hand, were first set on the sub-grade. This latter style is generally called telford pavement or macadam on telford foundation. With telford foundation. — Upon the sub-grade properly prepared as above described, shall be set by hand a single layer of sound and durable stone five (5) inches deep, in the form of a close pavement. The stones must be set in parallel rows across the street, with the largest side down, and they must break joints by at least one (i) inch. The top sides of the stones must not be more than eight (8) inches wide, nor less than four (4) inches wide. All interstices shall be filled with stone chips, firmly wedged by hand with a hammer, and all projecting points shall be broken off. The whole surface shall be thoroughly settled or rammed with a heavy sledge hammer, and the foundation left parallel to, and three (3) inches below the finished grade of the road. Broken stone course. — ^A layer of broken stone (limestone or some harder stone as may be selected) in sizes ranging between one and one-half (1%) and two (2) inches in diameter, shall be placed upon this foundation. It shall be of such a thickness that after being rolled and consolidated, its surface shall be two and one-half (2%) inches above the top of the founda- tion course. This layer shall be thoroughly wet and rolled, and during the process stone screened shall be introduced in such a manner and in such a quan- tity that all the interstices shall be entirely and completely filled. The rolling shall be continued till the road is thoroughly consolidated, and until the surface is smooth, and on the proper crown and grade. To secure this latter object, broken stone shall, if necessary, be added or removed from time to time during the process of the rolling. Wearing surface. — When this layer become thoroughly compact, screen- SPECI:PI CATION'S. 109 ings composed of limestone or some harder stone as may be selected, shall be spread upon the road to a thickness that will give a covering of one-half (Vi) inch in depth when rolled. Rolling and wetting shall then be continued until the surface is puddled and water flushes on it. The rolling shall be done with a heavy steam roller weighing not less than 2,500 pounds per foot of width of roller. The amount cannot be specified in advance, but it shall be sufficient to thoroughly compact and solidify the road. Macadam foundation. — When stones of uniform size are used for the foun- dation, these stones shall be good, sound limestone (or other hard stone as may be selected) broken so as to pass through a two and one-half (2%) inch ring. This stone shall be spread on the sub-grade and rolled in layers until a total thickness of five (5) inches is obtained, after which the top layers are to be applied as specified. For macadam pavements having thicker base. — When it is desired to have a thicker macadam pavement, extra layers of the foundation courses may be laid to give the added thickness to the pavement. Where telford foun- dation is used for the thicker pavement, the bottom stone may be slightly larger and the chinking in of smaller stone allowed to make this bottom course thicker in proportion to the extra depth of the pavement. Guarantee. — Some form of guarantee should be adopted for macadam pavement as well as for granite, asphalt and brick pavements. If the guarantee is made to run five (s) years and is covered by the retention of twenty (20) per cent, of the cost, four (4) per cent, to be paid each year after required repairs are made, the contractor would need to prac- tically resurface the street each year. Such a policy would naturally result in higher prices for this work, but would also place macadam street work more nearly on the same basis with the more substantial pavements. If the policy of requiring a guarantee on macadam pavement is adopted, the form of guarantee can be based upon those herein given for the other kinds of pavements. SPECIFICATIONS FOR GRANITE BLOCK PAVEMENTS. Paving blocks; quality, shape and sise. — The blocks shall be of granite, equal to the best quality obtained from "Blue Hill" in Maine, Westerly in Rhode Island, Millston in Connecticut, or Cape Ann in Massachusetts; the blocks must be uniform in quality, as to color, grain and hardness, show no laminations and be free from an excess of mica or feldspar. Soft or weather-worn stone, obtained from the sap of the quarry, will not be ac- cepted. The blocks must have fair and true surface on all sides, they must be split and dressed so that they can be laid with close end joints and side joints not exceeding one-half (Vz) of an inch. All blocks whose side faces vary more than one-half (Vs) of an inch from a rectangular shape will be rejected. The blocks must measure on the face or upper surface not less than three and one-half (3V2) nor more than four and one-half (4%) inches in width, not less than eight (8) nor more than eight (8) inches in depth; unless otherwise specially called for. The base or lower surface shall not be less than one-half (V2) inch in width and length than the upper surface. I lO PROPOSED MUNICIPAI, IMPROVEMENTS. The contractor shall have the blocks "culled" by competent persons, when delivered at the freight station, in order to remove all blocks which do not conform with the requirements. Any inferior blocks which are brought upon the line of the work will be condemned. Sample blocks. — Each bidder must submit a sample of the paving blocks which he proposes to use, at least three (3) days before the day adver- tised for receiving bids, or refer to sample on file heretofore submitted. In all cases the sample blocks must be labeled with the name of the contractor, the precise locality of the quarry from which it was obtained, and the name of the street in which the blocks are to be used. If at any time during the progress of the work, blocks of a diflferent kind or from a different quarry are intended to be used, new sample blocks must be submitted for approval in a like manner as in the first in- stance. The blocks from each quarry must be piled and laid in separate sections of the work, and in no case shall the blocks from different quarries be mixed in the work. The quality of the stone must in every case be approved before the blocks are brought upon the street. Placing the blocks upon the line of work. — The blocks shall be piled upon the front of the sidewalk, and care must be taken that they are not nicked or spalled in handling; no blocks are to be piled vyrithin three feet of any fire hydrant, and there is also to be left a sufficient passageway to each house upon the line of the street or highway. How to be laid and treated. — The blocks must be laid at right angles to the line of the street, and in straight lines from curb to curb, except in special cases when they shall be laid at such an angle as may be directed by the Engineer, who is also to determine the grade and crown to which the blocks must conform. Each course shall be of uniform width and depth, and so laid that all longitudinal joints shall be broken by a lap of at least, three inches; the stone blocks shall not be laid more than twenty-five (25) feet in advance of the ramming. No blocks or other material must be thrown or deposited in such a manner as to displace the blocks on the face of the work, and no carting must be done within twenty-five (25) feet of it. The sand bed must be perfectly dry before any stone blocks are laid upon it, and must be prepared for a distance of at least twenty- five (25) feet in advance of laying the pavement. Block paving on sand foundation. — If the joints are to be filled entirely with sand the blocks, as they are laid, shall be covered with clean, sharp sand, which must be broomed into the joints until they are completely fill- ed. The blocks shall then be thoroughly rammed to a firm, unyielding bed, leaving a uniform surface, which is to conform to the grade and crown of the street. All stones which settle below the grade line shall be raised or taken up by the person ramming, reset with sufficient sand beneath, and again rammed until they are brought to a uniform surface and unyielding bed. Any blocks which are broken by ramming must be entirely removed. No ramming shall be done within fifteen (15) feet of the face of the work that is being laid. Whenever the pavement shall have been constructed as described, for a SPECIFICATION'S. Ill distance of two hundred (200) feet it shall be covered a second time with a good and sufficient coating of dry, clean, sharp sand, and shall immed- iately thereafter be again thoroughly rammed, until the pavement is made solid and secure. A cover of sand one (i) inch in depth, shall be spread upon the pavement when it is completed. At no time must any paving be done when the stone blocks are wet, preventing the sand from running freely into the joints. Contractor to be responsible for five years. — The whole work of constructing and laying the said pavement and all its appurtenances, is to be done and completed in a workmanlike manner, and the contractor is, in general, to do all and everything that may be necessary for the construction, lay- ing, completing and maintaining of the best kind and quality of oblong granite block pavement, and to the satisfaction and approval of the city authorities, the contractor and his sureties shall be responsible in. every respect and at all times for a period of five (5) years from the date of acceptance of said pavement, for the complete and perfect construction and condition of said oblong granite block pavement, as herein provided. Guarantee. — The contractor shall have charge of and be responsible for the entire work until its completion and acceptance by the City; he shall in addition, guarantee to keep the pavement and its appurtenances in repair and good condition for a period of five (5) years after said ac- ceptance. The guarantee to consist in the City retaining six (6) per cent, of the total amount as per final estimate, for a period of two (2) years. At the expiration of the first year, the contractor will be paid three (3) per cent, provided he has made all the repairs necessary to maintain and place the pavement and its appurtenances in good condition, and replaced any material which may prove to have been defective or inferior quality when it was originally placed in the work. If the Contractor fails to make said repairs and furnish the new material, within ten (10) days after notice from the City authorities, or at the expiration of the time specified irre- spective of said notice; the amount of money held upon this contract may be applied to making the repairs and furnishing the new material. The balance, if any, between the amount expended by the City in mak- ing the necessary repairs and providing new material, and the three per cent, retained for the first year, shall be paid the Contractor, provided the pavement and its appurtenances are in good and complete condition. The terms and stipulations for repaving and maintaining the pavement and its appurtenances during the second year, shall be the same as those provided herein for the first year. The Contractor will, however, not be held responsible during the five (S) year guarantee, for any defects in the pavement or materials, which may have been caused by the opening of trenches after the pavement was completed and accepted; and will not be compelled to do the repaving over said trenches. Bonds. — In addition to the amount of six (6) per cent, retained the con- tractor is required to furnish two (2) bonds to the City of Harrisburg, satisfactory to the Board or officer having charge of the paving and ap- proved by such Board or officer, as to the sufficiency of said sureties and by the City or Corporation Counsel as to form, before the contract shall 112 PROPOSED MUNICIPAIv IMPROVE,MENTS. become effective; they must be delivered at the time of the execution of the contract. Such bonds shall be as follows: Character of bonds. — First. A bond for the faithful performance of all the provisions of the contract, relating to the construction and laying of the pavement and its appurtenances; said bond to be in the penal sum of the total amount bid by the contractor for the pavement and its appur- tenances. Second. A guarantee bond for the faithful performance of the contract provisions relating to repairing and maintaining the pavement and its appurtenances in perfect condition (with the exceptions relating to the openings in the pavements heretofore mentioned) at all times during the period of five (s) years from the date of acceptance of the pavement by or on behalf of the City. This bond shall be in the penal sum of one- quarter (%) of the total amount bid by the contractor for the construction and laying of the pavement and its appurtenances. This bond must be duly executed by the contracting party with a corporation as surety, and such corporation shall be duly authorized by the laws of the State of . Pennsylvania to become such surety, and be satisfactory to said Board or officer. SPECIFICATIONS FOR BRICK PAVEMENTS. Sand cushion. — ^Upon the concrete, when thoroughly set and the surface entirely cleaned from gravel, rubbish or covering of any description, shall be spread a bed of clean, sharp, screened sand, to a uniform depth of one and one-half (iVz) inches. The sand cushion shall be sprinkled, if so ordered by the Engineer, in order that it may settle into all crevices in the surface of the concrete. The sprinkling to be done with a rose attached to a hose or sprinkling can. The surface must be shaped to the true grade and crown before the laying of the pavement, by the use of proper templates and scrapers, which must be furnished by the Con- tractor. The prepared sand foundation must be kept at least sixty (60) feet ahead of the paving. Bricks or blocks. — The make or brand of bricks or blocks of which sam- ples have been tested and approved as to quality by the city authorities, will be accepted for this paving. If any bidder or maker desires to present other paving bricks or blocks, they must deliver ten (10) samples accompanied by an affidavit as to time of use and ability of plant to furnish same, at least three days before the time advertised for receiving bids. Bidders on bricks or blocks which have not been used for street paving for at least two years in quantities of S,ooo square yards in a city of at least 8,000 inhabitants will be required to give a guarantee bond for a period of three years additional to the five years .specified for brick for which affi- davit of such use is furnished. Bricks and blocks must be tough and especially burned for street pav- ing, and of the very best quality, free from cracks and blisters and all defects, uniform in color and size, and must measure not less than ordinary brick size, nor more than ordinary block size. Bids will be in- a u f-« (- u p cr: H in H rii u LlI X u n t< rt h 1- < a: •< u "<; h UJ M K m — ii ij Jl;: ;. ■ r i^ o < J3^ i.'; 5^1 ^ ID S > m S in " fei: in z ifl < < D Z _j LU 5 n- o EC s til z 1=1 UJ m QJ cc z a u t- o ui Ui z -I Lu < a K I I- m z ^ I in « LU 1- 1; D z S ! LU " s < :a X UJ LU —1 > n s Q. • tC 3 CL m i U1 cc o -1 m a. *) ID - — ■ ; ."^ffi"^ ■ Yj :.:..:!:..■:,..::■■ 1?, ■:i; spEcnnCATioNS. 1 1 3 formal 'Cm 'any other size. The 'contractor to whom contract is awarded will be Inquired to deposit by the time of executing the contract a new set oi at least six samples of the kind of bricks or blocks proposed to be tised in this work. The bricks and blocks must be capable of standing the following tests r Ahsorption test. — They shall not absorb more than three (3) per cent, of their own weight in water after being broken and dried in an oven and then immersed for 24 hours. Abrasion test. — They shall not lose more than an average of eight (8) per cent, in an abrasion test conducted in the following manner and under similar conditions as the tests heretofore made by the Board or officer having charge of the letting of contract. The bricks will be placed in a rumbler 21 inches in diameter, making from 43 to 45 revolutions per min- ute and containing 150 pounds of rough scrap iron, a majority of the pieces weighing about one pound, and three pieces about 4 pounds each (it is intended in conducting this test to use the same scrap iron with an additional weight sufficient to bring it up to 150 pounds, as was used in a comparative test heretofore made), the result in percentage lost being an average of the following three percentages: First. The percentage lost in the first 20 minutes. Second. The percentage lost in the second 20 minutes. Third. The percentage lost in the above 40 minutes. Bricks and blocks will be placed separately in the rumbler. Transverse breaking test. — ^All bricks or blocks must give modulus of rupture of not less than 1800 when tested on their sides, being supported on knife edges 6 inches apart. The above coefficients to be calculated by the formula: 3 W L Modulus.. in which W equals breaking weight in pounds at 2 A D the centre; L equals length in inches between supports; A equals area of section of brick or block in square inches; D equals depth of brick or block in inches. The city reserves the right to accept bids on bricks or blocks, which have successfully passed the above requirements in the test heretofore- referred to, made under the direction of its Board or officer. If samples are submitted on other bricks or blocks they will be sub- jected to similar comparative tests as those heretofore mentioned, and if samples do not meet these requirements, bids upon such bricks or blocks- will be informal and not considered. Bricks delivered to conform to samples. — All bricks delivered on the work must be within ten per cent, of the requirements of the standard tests,, and the City will have the right at any time during the progress of the work to reject any or all bricks which do not reach this percentage, and such bricks must be immediately removed from the work. All bricks brought upon the. line of the work for the construction of the pavement shall be subject to inspection by the Engineer. All bricks rejected must be immediately removed therefrom. All culling necessary shall be done before the bricks are laid, as well as after being laid, and the contractor- 8 1J4 PROPOSED MUNICIPAL IMPROVEMENTS. shall furnish skilled and competent labor for that purpose. The culling- shall be done under the direction of the Engineer or his representatives, whose decision as to quality shall be final. Piling bricks on the sidewalk. — The bricks shall be piled on the front of the sidewalks so as to leave a sufKcient passageway to each house, and to leave a clear space of three feet from all fire hydrants. How laid. — The bricks shall be laid on edges, perpendicular to the grade or crown, and at right angles to the curb lines, in true and straight align- ment; except at street intersections, where they shall be laid at such an angle and in such manner as may be directed by the Engineer. They shall be laid with close joints and with a lap of at least three inches; the joints being kept as near the centre of the brick in the next course as may be possible. No broken bricks will be allowed in the pavement, except in commencing or closing of a course. After the bricks have been laid for a sufficient distance along the street, the surface shall be swept clean of all rubbish, and then thoroughly rolled with a steam roller, weighing not less than five (s) tons, or rammed where the roller cannot reach the pavement, with a rammer weighing not less than sixty (60) pounds. An oak plank, two inches thick, from ten to twelve inches wide and twelve feet long must be used under the rammer. The rolling or ramming must be continued until the surface is brought to a uniform grade, so that it shows no continuous lines or unequal settle- ments produced by the roller or rammer. All bricks which are chipped, or broken in the process of rolling or ramming, or are otherwise defec- tive, must be removed and sound ones rammed in their place. If directed by the Engineer, the surface of the pavement, after it is rolled and recti- fied, shall be thoroughly wet with clean water, so that all soft bricks may be detected, which must be replaced with good, hard brick. The bulk of the pavement is to be done with cement grout, excepting such parts of it as described below. Grouting. — Portland cement grout shall be poured into the joints, until it appears on the surface. The grout shall be broomed into joints, and -the operation must be continued until the joints are thoroughly filled flush with the surface. The grout must be mixed in a suitable apparatus, in which the grout must be continually stirred until it is poured into the joints. Should any irregularities appear upon the surface of the pavement, then the rammer must be used to bring it to an even and solid bearing before the grout has set. A thin layer of clean, sharp sand shall be ■spread over the pavement, after the grouting is done, and it is not to be removed until the contractor is notified by the city authorities. Cement grout. — The cement grout shall be composed of one measure of freshly burned American Portland cement to one measure of clean, sharp, screened sand; both to be mixed with clean water to a consistency which will readily permeate all joints. The Portland cement must give a tensile test of at least 150 pounds to the square inch, after 24 hours (one hour in air and twenty-three in water) and 300 pounds per square inch, after seven (7) days. Filling with paving pitch. — The contractor must provide a strip of wood •one and one-half inches thick and six inches wide, which must be placed SPEciFiCATioisrs. 115 along the curb-stones and kept in place until the joints are grouted. Thereupon the strip of wood must be removed and the void filled with paving pitch, of a quality described in a subsequent section of the specifi- cations. To facilitate the removal of this plank after the rolling and grouting has been done, small wedges should be used between the plank and the curb. The contractor must also fill with paving pitch all joints contained within six rows of brick or blocks, extending from curb to curb and at intervals of fifty (50) feet, throughout the whole length of each block. Street to be kept closed. — The street shall be kept closed and no traffic or carting must be allowed for ten days after grouting. The contractor shall erect sufficient and well constructed barricades, and furnish watchmen at all times to see that this provision of the specifications is complied with. Should the bond between the bricks become broken for any reason, the joints at such places shall be cleaned, even if it be necessary to relay the brick; and such parts shall be regrouted and rebarricaded. Filling joints with paving pitch. — The joint between the brick pavement and the curb, also five joints at intervals across the street every fifty (50) feet, must be completely filled with paving pitch, which shall be composed of twenty (20) parts of refined "Trinidad Lake" asphalt, and three parts of oil mixed with one hundred parts of pitch, both obtained from a direct distillation of coal tar, and ordinarily numbered four (4) at the manufac- tory. The proportions must be obtained by weight. The contractor must furnish the Engineer with an affidavit from the manufacturer or refiner stating that the materials are the kind specified. The preparation must be used at a temperature of no less than 300 de- grees Fahrenheit when poured into the joints, which must be done with suitable implements so that the paving pitch is not spilled over the bricks. The pouring must be done from the centre to the sides. As the joints are filled, fine and thoroughly dry sand must be sprinkled upon the filling of the joints so that it combines with it. If required, the sand must be heated. The sand bed and the brick must be free from moisture before any filling is done. The pavement must be finally covered with a thin layer of clean, sharp sand, which must be removed upon notice from the Engineer. When repairs are to be made. — The general repairs must be made between April 1st and November ist of each year, unless specially permitted at other times by the City Engineer, who shall be notified by the contractor, in writing, when any repairs are intended to be made. All work and ma- terials required to repair and maintain the pavement and its appurtenances must comply with the conditions relating thereto in these specifications. Contractor to be responsible. — The whole work of constructing and laying the said pavement and all its appurtenances, is to be done and completed in a workmanlike manner, and the contractor is in general, to do all and everything that may be necessary for the construction, laying, completing and maintaining of the best kind and quality of brick pavement, and to the satisfaction and approval of the Board of City authorities, and while the said work is to be done under the inspection or supervision of the Board or its authorized agents, yet the contractor and his sureties shall ri6 PROPOSED MUNICIPAL, IMPROVEMENTS. be responsible in every respect and at all times for a period of five (s) years from the date of acceptance of said pavement, by or on behalf of the City of Harrisburg, for the complete and perfect construction and condition of said brick pavement, as herein provided. Guarantee. — The contractor shall have charge of and be responsible for the entire vifork until its completion and acceptance by the City; he shall in addition guarantee to keep the pavement and its appurtenances in repair and good condition for a period of five (s) years after said accept- ance. The guarantee to consist in the City retaining ten (lo) per cent, of the total amount as per final estimate for a period of two (2) years. At the expiration of the first year the contractor will be paid five (s) per cent., provided he has made all the repairs necessary to maintain and place the pavement and its appurtenances in good condition; removing all depressions or humps in the surface, restoring to it a uniform grade and replacing any work or materials which may prove to have been defective or of inferior quality, when originally done or placed in the street. If the Contractor fails to make said repairs and furnish the new materials within ten (10) days after notice from the City Engineer or at the expiration of the time specified, irrespective of said notice, the amount of money held upon this contract may be applied to making the repairs and furnishing the new material. The balance, if any, between the amount expended by the City in making the necessary repair and providing new material, and the five per cent, retained for the first year, shall be paid the contractor, provided the pave- ment and its appurtenances are in good and complete condition. The terms and stipulations for removing and maintaining the pavement and its appurtenances during the second year shall be the same as those provided herein for the first year. The contractor will, however, not be held responsible during the five (S) year guarantee, for any defects in the pavement or materials, which may have been caused by the opening of the trenches after the pavement was completed and accepted; and will not be compelled to do the repav- ing over said trenches. Bonds. — In addition to the amount of ten (10) per cent retained, the contractor is required to furnish two (2) bonds to the City of Harrisburg each with two sureties or surety company satisfaction to the Board or officer having charge of the paving and approved by such Board or officer, as to the sufficiency of said sureties, and by the City or Corporation Counsel as to form, before this contract shall become eflfective; they must be delivered at the time of the execution of the contract. Such bonds shall be as follows: Character of bonds.— First. A bond for the faithful performance of all the provisions of the contract relating to the construction and laying of the pavement and its appurtenances; said bond to be in the penal sum of the total amount bid by the contractor for the pavement and its appurte- nances. Second. A guarantee for the faithful performance of the contract pro- visions relating to repairing and maintaining the pavement and its appur- tenances in perfect condition (with the exceptions relating to the openings SPECIFICATIONS. 117 in the pavement heretofore mentioned) at all times during the period of five (s) years from the date of acceptance of the pavement by or in behalf of the City, the contractor to make all repairs which are due to defective workmanship and materials, and to furnish new and proper materials in place without any compensation. This bond shall be in the penal sum of one-half (%) of the total amount bid by the contractor for the con- struction and laying of the pavement and its appurtenances. This bond must be duly executed by the contracting party with corporation as surety, and such corporation shall be duly authorized by the laws of the State of Pennsylvania to become such surety, and be satisfactory to said Board. In case the particular make of brick has not been manufactured or in successful use in quantities of 5,000 square yards in a city of 8,000 inhabi- tants for at least two years, then and in that case the guarantee bond shall be for a period of eight years under the same conditions as stated above for the five-year guarantee bond. SPECIFICATIONS FOR ASPHALT PAVEMENTS. Header curb. — A header curb must be placed at the terminus of the asphalt pavement where directed; it shall be five (s) inches thick and not less than sixteen (16) inches deep, and set in concrete in the manner described for curb-stone. Bituminous concrete. — Upon the concrete foundation, when set and dry, shall be laid the binder course of bituminous concrete made of clean broken stone and asphalt cement, which is to be of the same quality as that used in the wearing surface; for rock asphalt, other kinds of asphalt of approved quality can be used. The broken stone shall pass through a 1% inch screen; eighty-five (85) per cent, shall pass in its longest dimension; of the remaining fifteen (is) per cent, none must have a larger diameter than iVa inches; and the stone, after passing the heating drums, shall contain more than five (s) per cent, of material which would pass a No. 10 screen. The broken stone must be heated to a temperature not exceeding 300° F. and then thoroughly mixed by machinery with asphalt cement in the proportion of about six (6) to seven (7) pints of cement to one cubic foot of stone. The binder must have life and gloss, without an excess of cement; should it appear dull from overheating or want of cement it will be re- jected. No binder must be laid when it rains. The binder must be hauled to the work while hot, having a temperature of not less than 250° F. when delivered upon the street; then spread with hot iron rakes and immediately rolled with a steam roller weighing not less than five (s) tons, while in a hot and plastic condition, until it is cold and has an average thickness of iVa inches in striking the average. In places where the binder cannot be rolled it must be thoroughly rammed. The upper surface must be made parallel with the finished surface of the pavement when it is completed. Wearing surface.— Upon the binder course will be laid the wearing sur- face or pavement proper, of which the basis shall be pure asphalt un- mixed with any products of coal tar. Il8 PROPOSED MUNICIPAI. IMPROVEMENTS. STANDARD PAVEMENT MIXTURE. The standard pavement mixture for the wearing surface shall be com- posed of: 1. Asphaltic cement. Refined asphalt; heavy petroleum oil or liquid asphalt. 2. Clean, sharp sand. 3. Finely powdered carbonate of lime, granite or quartz. Refined asphalt. — The crude asphalt used in the preparation of the Stand- ard Pavement Mixture shall in all respects be satisfactory to the Board of Street Commissioners; it must be refined until the product is uniform in composition, quality and specific gravity. The refined asphalt shall con- tain not less than fifty-two (52) per cent, of bitumen soluble in carbon bisulphide, of which bitUmen at least sixty (60) per cent, shall be soluble in Pennsylvania petroleum naphtha having a specific gravity of 72 degrees Beaume (boiling points 80 degrees to 90 degrees centigrade.) The bitu- men shall soften at 189-210 degrees, and flow at 200-240 degrees Fahren- heit; it shall volatilize from 0.5 to 3 per cent, of oil in-io hours, at a tem- perature of 400 degrees F.; it shall have approximately a specific gravity between the limits 1.38 and 1.4S, and be free from all manner and form of adulteration. Heavy petroleum oil. — ^The heavy petroleum oil must have the lighter oils extracted by distillation without cracking until the oil has a specific gravity of 18-22 degrees Beaume, and the following properties: i. Flash-test, not less than 300 degrees F. (The flash-test shall be taken in a "New York State closed oil tester.") 2. Fire-test, not less than 350 degrees F. 3. No appreciable light oils or matter volatile under 250 degrees F. 4. Distillate less than 10 per cent, at 400 degrees F., for 30 hours. (The distillation shall be made with about 50 grammes of oil in a small gas. retort provided with a thermometer, and packed entirely in asbestos.) S. The residue in the retort after distillation, must be fluid at 75 degrees F., and not coarsely crystallized on cooling. 6. It shall be free from for- eign matter and coke. Asphaltic cement. — From the refined asphalt and the heavy petroleum oil agreeing in composition and properties with those described in the fore- going paragraphs, the asphalti? cement shall be prepared in the follow- ing manner: To the melted asphalt, at a temperature of not over 325 de- grees Fahrenheit, shall be added the heavy petroleum oil, after having been heated at least to 250 degrees F.; in suitable proportions to pro- duce an asphaltic cement, which must contain from 18 to 21 pounds of oil per 100 pounds of refined asphalt. When the oil is being added, agi- tation shall be kept up with suitable appliances, until a homogeneous cement is produced; this shall be accomplished in at least 10 hours, during this time the temperature must be maintained at 250-350 degrees F., but no higher. The cement can then be used, if it is homogeneous and free from lumps; should it not be homogeneous, either hot oil or melted asphalt must be added in the necessary proportions to make the correc- tion. The asphaltic cement shall fulfill the tests prescribed for the heavy petroleum. SPECIFICATION'S. 119 When asphalt cement is kept in storage, it must be thoroughly agitated when used, also all dipping kettles while in use. Samples of the asphaltic cement and the heavy petroleum oil shall be supplied the Engineer or his agents at all times in suitable metallic boxes or cans. Sand. — The sand must be hard-grained, moderately sharp and clean, con- taining not more than one per cent, of hydrosilicate of aluminum. On sifting, the whole of it shall pass a lo-mesh screen, twenty per cent, shall pass an 80-mesh screen, and at least seven per cent, shall pass a lOO-mesh screen. Carbonate of lime, etc. — ^The powdered carbonate of lime, granite, or quartz must be of such a degree of fineness that the whole of it will pass a So-mesh screen, and at least sixty-six (66) per cent, a 200-mesh screen. Paving mixture. — The materials complying with the aforementioned speci- cations, shall be mixed in the following proportions by weight. Asphaltic Cement, from 16 — 20 Sand, from 79 — 65 Pulverized carbon of lime, granite or quartz, from s — 15 The proportions of the materials used will depend upon their character as shown by analysis and tests. Said proportions will be subject to the approval of the Board of Street Commissioners, but the percentage of bitumen and petroleum residum in any paving mixture, soluble in bisulphite of carbon, shall not be less than nine and one-half (9%) nor more than twelve (12) per cent. The sand boxes and asphalt gauges must be weighed in the presence of the Engineer or his agents, when required. The pavement mixture must be brought to the ground in covered wagons at a temperature of not less than 250 degrees Fahrenheit, and when the temperature of the air is less than 50 degrees Fahrenheit, the contractor must, if directed, provide iron carts with heating apparatus, in order to maintain the proper temperature of the mixture. Pavement mixture, how laid. — It shall then be carefully spread upon the binder course, but in no case when it is wet or when raining, by means of hot iron rakes, in such manner as to give a uniform and regular grade; and to a depth of three and one-third (3-1/3) inches, so that, after having received its ultimate compression of about two-fifths, it will have a thick- ness of two inches. If there should be any moisture on the binder sur- face, it must first be removed and the surface may dry by heating, if necessary. The surface will then be compressed by hand rollers after which a small amount of hydraulic cement will be swept over it, and it will then be thoroughly compressed by a steam roller weighing not less than 250 pounds to the inch run, the rolling to be continued for not less than five hours for every 1,000 yards of surface. Coating gutter with asphalt. — In order to make the gutters, which are consolidated but little by trafKc, entirely impervious to water, a width of 12 inches next the curb must be coated with hot, pure asphalt, in 120 PROPOSED MUNICIPAL IMPROVEMENTS. order to saturate the pavement to a certain depth with an excess of asphalt, which is to be smoothed with hot smoothing irons. Brick pavement in gutters. — When called for in the proposal for bids, the gutters must be paved with vitrified paving bricks or blocks of approved quality, to the width of about thirty (30) inches. The bricks or blocks must be set upon a .concrete base six (6) inches thick, which is to be made and laid in the same manner as prescribed for the asphalt pavement. After the concrete has sufficiently set, a dry mix- ture composed of one (i) part cement and two (2) parts of fine sand, thoroughly mixed, will be spread upon the concrete, to the depth of not less than one-half inch, and regulated so as to be exactly parallel to the finished grade of the gutter. On this bed the bricks or blocks will be set on edge, with the longest dimension at the right angles to the curb. The longitudinal joints of each course must be broken by a nap of not less than four (4) inches; only half brick shall be used for breaking joints. The outer edge must form a straight line. The bricks or blocks shall then be carefully rammed, by placing a plank over several courses and ramming the plank with a heavy rammer. The ramming must be continued until the bricks or blocks are firmly bedded and present a uniform surface, with a proper grade. Any lack of uniform- ity in the surface must be corrected by taking up and relaying them. The entire gutter will then be grouted with a thin easily flowing grout, of neat Portland cement, until the joints are completely filled. The contractor will receive the same price per square yard for the brick pavement as that bid by him for the asphalt pavement. General requirement. — The asphalt for use, under this contract, shall be one agreeing in composition and properties with that described in the foregoing section (under the heading of "Standard Pavement Mixture"), or one having composition and properties which are equivalent or superior thereto, to be determined by the Board of Street and Water Commis- sioners; but whatever may be the character of the asphalt used or the manner of manipulation and laying, the pavement obtained therefrom must conform to the following general requirements, namely: "The pave- ment when laid shall not be so soft as to be unfit for travel on the hottest days of summer, nor so hard as to disintegrate from the effects of frost or cold; when laid, it shall be equal in consistency, surface, durability and other properties, to the standard pavement made as hereinbefore de- scribed; it shall contain no water, nor appreciable amount of light oils, nor matter volatile at a temperature under 250 degrees Fahrenheit; it shall yield, when extracted with bisulphide of carbon and after evapora- tion of the solvent, not less than nine and one-half (9%) nor more than twelve (12) per cent, of pure bituminous matter which shall have equal or superior qualities to the bituminous matter extracted from the standard pavement mixture, to be determined by the Board of Street Commission- ers. The extracted bituminous matter shall have a fire test of 350 F., and shall pass a lo-mesh sieve (per lineal inch), and not less than IS per cent, shall pass a loo-mesh sieve, while the remainder shall be graduated SPECIFICATIONS. I2l between these limits. If rock asphalt be used the mineral matter shall be that which occurs in the natural product. No rock asphalt must be used in streets where the longitudinal grade is over one and one-half (i%) per cent. Statement required. — The persons or corporations not having any asphalt pavement on any of the public highways in this city, under the jurisdiction of the Board of Street Commissioners, are required to submit a state- ment in writing, accompanying the other statements below mentioned, whether such persons or corporation have laid asphalt pavement in any other city; if so, to name the cities, the area of the pavement, and whether laid with the same kind of asphalt which they intend to use in performing the work under this contract. Also whether the persons or corporation are fully prepared with the necessary capital, equipments and skilled labor to carry out the work herein specified. The statement to be satisfactory to the Board of Street Commissioners. Each bidder must deposit with the Engineer, at least five (s) days be- fore the time advertised for receiving bids, samples in suitable boxes and jars of the following materials intended to be used, properly labeled with the name or brand of the contents, with certificates and statements, under oath, viz: 1. A sample of not less than five (s) ounces of Crude Asphalt with a certificate stating where the material was mined. 2. A sample of not less than five (s) ounces of Refined Asphalt. 3. A sample of not less than two (2) pounds of the liquid Asphalt Flux or Petroleum Residum. (No samples of Flux in glass vessels will be re- ceived). 4. A sample of not less than eight (8) ounces of the Asphaltic Cement, with a statement of the formula used in its composition; all quantities being expressed in pounds. 5. A sample of not less than five (s) ounces of Sand. 6. A sample of not less than five (S) ounces of pulverized Carbonate of Lime, Granite, or Quartz. 7. A sample of not less than four (4) pounds of the Paving Mixture for the wearing surface as it will be laid on the street, with a statement of the formula used in its composition, all quantities being expressed in pounds. If the bidder proposes using rock asphalt, samples 3, 4, S and 6 will not be required. 8. A statement of the location of the asphalt refinery, and of the loca- tion and capacity (in square yards per day) of the plant where the paving mixture is prepared. N.B.— No bids will be considered formal, unless the above mentioned samples, certificates and statements included in numbers i to 8 have been submitted. All of them to be subject to the approval of the Board. It will be required that the various deliveries as shown by samples taken from the work during its continuance, and when tested, shall exhibit qualities equal' or superior to those developed by the samples submitted as aforesaid, and no change therefrom or in the proportions of mixture shall be made, without notice to and the permission of the Board of Street Commissioners. 122 PROPOS^eD MUNICIPAI, IMPROVEMENTS. If the above mentioned samples, certificates and statements required by these specifications, relating to the asphalt pavement materials, have been once submitted during a calendar year and approved by the Board, an affidavit accompanying any subsequent proposals, during said year, that the same materials, their compositions and formula are to be again used, will be considered sufficient; otherwise, the hereinbefore described conditions will remain in force. To examine the plant, etc. — ^The Engineer or any of his authorized agents shall at any time have free access to the plant and materials belonging to the contractor, and have the right to take a sample of the various materials composing the wearing surface, for the purpose of making examinationsj. tests and analysis. Guarantee of maintenance. — The contractor must give a guarantee bond, as hereinbefore provided, to keep the pavement in a good and uniform con- dition, and the curbing in proper grade and line for a period of ten (lo) years from the date of its acceptance by the city. Conditions to keep in repair. — During the period of ten (lo) years, the contractor, at his own expense, must keep the pavement in repair under the following conditions: First. The wearing surface shall not be reduced more than one-half (%) inch from the original thickness at the end of ten years; that is, it must be one and one-half (1V2) inches thick at the end of ten years. Second. Places which show a disintegration of the material shall be re- moved to the binder or concrete foundation, as found necessary, and re- placed with a new material having the same thickness and conforming to the adjacent pavement; and the gutters must be recoated with hot asphalt whenever necessary. Third. All elevations or depressions one-half of an inch or more, above or below the general surface of the street, shall be brought to the same elevation as the general surface; these elevations and depressions are to- be determined by measuring from a straight edge four (4) feet in length, placed on the surface of the pavement parallel to the line of curbing. In making such- repairs the process known as "skimming"' may be em- ployed. Fourth. Where elevations or depressions are due to the failure of the concrete foundations, from any cause, the asphalt and concrete shall both be removed, a length and a width, to include the entire defect. If the failure is due to the buckling of the concrete, the new foundation shall consist of broken stone thoroughly compacted and the same thickness as the original concrete. In all other cases a new foundation of concrete shall be placed of the same quality and thickness as the original con- struction. Upon the foundation shall be placed the pavement of the same thickness as the adjacent surfaces. Fifth. Cracks which show any disintegration, or which are three- eighths (%) of an inch or more in width, shall be cut out of the binder or concrete foundation, as found necessary, a length and a width sufficient to include the entire portion affected, this portion to be replaced with new material of the same quality and thickness, as shown in the pavement ad- jacent thereto. SPECIFICATIONS. 123 Sixth. Should it be found necessary to replace forty per cent, or more of any city block with new material, the entire surface of such block shall be resurfaced. Seventh. No old asphalt or binder material shall be used over, but taken to a dumping place. Eighth. The general repairs are to made between April ist and October 1st of each year, unless specifically permitted, in writing, by the City Engineer to make them at other times. The contractor must cut the pavement at various places, if required, in order to make any test, and restore it to its former condition, with- out extra compensation if the pavement is in any manner defective; otherwise he shall be paid at the same rate per square yard as the con- tract price. The City Engineer shall be notified by the contractor in writing, when any repairs are intended to be made. Replacing pavement over new trenches. — The contractor shall also replace the asphalt pavement when it has been removed to make a sewer, water or gas connection, or any other connection or opening for which permits have been issued, for which work the contractor shall receive the original price bid per square yard. The concrete foundation shall in no case be less than six (6) inches in thickness, and it shall consist of one (i) part Portland cement, three (3) parts of sand, and five (s) parts of broken stone; all the material to be of the quality, mixed and laid in the manner as specified in this contract. The contractor will receive no further com- pensation for the repair of any damaged or sunken pavement once laid by him over such openings, except as provided for in this contract for maintenance and repairs. Failure to make repairs. — In case the contractor fails to make the neces- sary repairs, as provided for in these specifications, during the period of said guarantee, then the City Engineer in behalf of the City, shall have the right to purchase such materials as he may consider necessary, and to employ such persons as he may deem proper to undertake and com- plete the repairs, or to have them done by contract, after forty-eight hours from the date of serving upon the contractor or his legal repre- sentatives, a written notice to do the necessary repairs. The cost of such work shall be collected from the contractor or his sureties, or de- ducted from any sum due or to become due to the contractor under the provisions of this contract. Contractor to be responsible for ten years. — The whole work of constructing and all its appurtenances is to be done and completed in a workmanlike manner, and the contractor is, in general, to do all and everything that may be necessary for the construction, laying, completing and maintain- ing of the best kind and quality of asphalt pavement, and to the satis- faction and approval of the Board of Street Commissioners of the City of Harrisburg; and while the said work is to be done under the inspection or supervision of the Board or its authorized agents, yet the contractor and his sureties shall be responsible in every respect and at all times for a period of ten (10) years from the date of acceptance of said pavement,, by or on behalf of the City of Harrisburg, for. the complete and perfect 1 24 PROPOSED MUNICIPAI/ IMPROVEMENTS. construction, repair and maintenance and condition of said asphalt pave- ment as herein provided. And it is hereby expressly agreed and under- stood by and between the parties hereto that the said party of the first part, its successors and assigns, shall not, nor shall any department or officer of the municipality of the City be precluded or stopped by any return certificate or estimate made or given by any Engineer, Inspector or other officer, agent or appointee of said Board of Street Commission- ers, or of said party of the first part, under or in pursuance of anything in this agreement contained, from at any time showing the true and cor- rect amount and character of the work, or any part thereof, which shall have been furnished by the said party of the second part, or by any person or persons under this agreement; and no inspection, approval or acceptance of the work or materials or of any part thereof, or of any payment made on account thereof, shall prevent the party of the first part from objecting to the acceptance of such work or materials at any time thereafter during the existence or continuance of this contract. Time of acceptance. — Final acceptance of the work under this contract will not be made between the fifteenth day of November and the fifteenth day of April next succeeding, unless otherwise directed by the Board of Street Commissioners. Character of bonds. — ^The bonds which the contractor is required to give shall consist of two bonds to the City of Harrisburg satisfactory to the Board, and to be approved as to the sufficiency of the sureties by the said Board, and as to form by the City or Corporation Counsel, before such contract shall become effective and must be delivered at the time of the execution of the contract. Such bonds shall be as follows: First. A bond for the faithful performance of all the provisions of such contract relating to the laying and constructing of the asphalt pavement and its appurtenances, which shall be in the penal sum of the amount bid by the contractor for the pavement and its appurtenances. Second. A guarantee bond for the faithful performance of all the con- tract provisions relating to repairing, repaving and maintaining of such pavement and keeping the same in complete and perfect condition at all times for a period of ten years from the date of acceptance of said pave- ment by or on behalf of the City. This bond shall be in the penal sum of one-half of the amount bid by the contractor for the laying and con- structing the pavement and its appurtenances in the first instance. This bond must be duly executed by the contracting party with a corporation as surety, and such operation shall be duly authorized by the laws of the State of Pennsylvania to become such surety and be satisfactory to the City. For maintaining and repair of the pavement and its appurtenances dur- ing the second period of five years, as hereinafter provided, the sum of twelve and one-half (12%) cents per square yard. Which svim shall be paid by the City when due upon the conditions herein stated, in addition to the amount bid per square yard for the asphalt pavement. Additional penalty for not commencing and completing on time. — If the con- tract work is not commenced and fully completed according to the terms of the contract -within the time herein limited for its performance, unless GUARANTEES TO THE CITY. 125 further time for the commencement and completion be granted to the contractor by said party of the first part, the contractor shall forfeit and pay for each day that may elapse after the time so limited for its com- mencement and before its final and full completion the sum of three dol- lars per day, when the gross amount to be paid to the contractor shall be less than three thousand dollars and two dollars per day additional for every two thousand dollars above that sum. Penalties to be deducted from payment for contract. — Where the penalty or forfeiture is imposed by the term of this contract for the failure, neglect or default of the contractor in the performance of this contract, or where such penalty or forfeiture is imposed or declared by the laws of the State or the ordinances of the City, the amount of every such penalty or for- feiture, when incurred by the contractor, may be deducted and withheld from any money due or to become due upon his contract, and when so deducted and withheld shall be deemed and taken as payment to that extent. Contract not to be sub-let. — The contractor will not be allowed to sub-let the whole or any part of his work, or make an assignment of the con- tract, or of the moneys to be paid to him thereon without special permis- sion in writing from the Board or officer having charge of the contract. It is of course essential that specifications particularly for public work where open competition must be allowed, should be care- fully prepared and the class, material and workmanship desired, accurately described. It is, however, even more important that the inspection of the work and materials furnished should be thor- ough and embrace every part of the construction. Where practicable, reHable guarantee bonds, preferably from a surety company, as suggested in the above specifications, should be required to insure a satisfactory condition of the pavements at the end of a series of years. Such guarantees not only insure good results for the city, but in themselves act as an incentive for greater care on the part of the responsible contracting party. But such guarantees should not be considered sufficient without thor- ough inspection on the part of the City. I desire to call particular attention to the clause in the specifications for asphalt regarding the condition in which the pavement is found at the end of the guarantee period. These requirements are based upon those adopted by the American Society for Municipal Improvements, and are particularly recommended as giving the most exact basis upon which the amount of work which may be required from the contractor at the end of the guarantee period, can be accurately determined. A sweeping statement that the pavement must be in a good state of repair has always caused trouble in determining just what should be required of the contractor. 126 PROPOSED MUNICIPAIv IMPROVEMENTS. For well-laid pavements the annual cost for maintenance and repairs, after the end of the guaranteed period, will be much less for brick than for asphalt pavements. This fact should be con- sidered in comparing the two pavements, particularly when the maintenance becomes an annual city charge and the property owner cannot be assessed for a second pavement, as I understand is the case in Harrisburg. For any extended public improvement in the way of pavements, samples of the various essential materials to which reference may be made in the individual specifications, should be kept on file in the office of the board or body receiving the bids. Such standards when carefully selected, should materially assist in getting uniform work done and in having all the contractors bid on the same basis. The laws regarding the assessments for pubhc improvements vary greatly. Where extended improvements are contemplated, it has been found very satisfactory to assess an arbitrary percent- age of the work upon the City at large. This percentage varying from fifty per cent, of the entire cost down to an amount practically equivalent to the cost of the street intersections. Pavements while being of specific benefit to the contiguous property, are no doubt a great advantage to the City taken as a whole. These are hardly questions of engineering and the percentage of the assessments which should be borne by the City, should, I think, be carefully considered by your committee. I understand that the present practice in your City in regard to this matter is to place practically the entire assessment upon the abutting property owners, allowing payments to be made in ten annual instalments, upon which 6 per cent, interest is charged, the contractor being paid in the bonds against improvement. It has been found of advantage in a number of cities to limit the instalments to three or five years, and to have a general paving fund either from a bond issue or from a fixed amount in the gen- eral tax levy from which the contractor may be paid after the completion of the work. This fund is eventually used for paying the city's portion of the work, all payments of instalments being credited to the fund, which is thus replenished from year to year and the amount of paving ordered each year is Hmited to the amount of money available in the fund. Such method is generally popular and is an inducement for property owners to petition for pavements. It also insures the contractor of immediate payment and therefore results in low prices. PROVISION FOR UNDERGROUND CONSTRUCTION. l2^ Before streets are paved it goes without saying that all of the underground constructions should be placed in a first-class condi- tion and the several services for sewer, water and gas connections should be laid, even to vacant lots, to prevent the tearing up of the pavement. In actual practice this is seldom done and often would result in having a lot of services in the street which would never be used. Some safeguard, however, should be provided to reduce to a minimum the number of openings made in new pavements. Notices should be served on all property owners to put in service connections and for all buildings along the line of the pavement, the laying of the services should be imperative. Repairs where pavements are cut, should in all cases be made by the city authori- ties, and to insure satisfactory results, even the back filling on the ditches should also be done by the City or under direct supervision of the city authorities. A deposit or payment sufficient to cover the expense of all work in connection with making repairs to pave- ments, should also be required before permits are issued. Where pavements having a concrete base are cut, it has been my practice to require the concrete to be taken out for six inches wider than the ditch and to require the use of Portland cement in renewing the concrete. This method gives a stronger concrete than that obtained from Rosendale cement and by extending over the sides of the ditch acts as an arch to prevent settlement. Thanking your committee, your secretary, and your city engi- neer for the information given and the courtesies extended, I am Respectfully yours, M. R. SHERRERD, Consulting Engineer. ►^