A Handy Manual Containing Valuable Information for Architects and Builders _ itsburgh Plate Glass Phas . i Milwaukee, Wisc. Digitized by the Internet Archive in 2022 with funding from Columbia University Libraries https://archive.org/details/glassglazingOOunse 2 6 Pool. DB Y Ll The National Glass Distributers Ass’n All Rights Reserved INN TITUUULUUUUUNVNNNNN UVR LLLLLUTTTTHAQUUCUUULULLLULAAHHAU ULL | Che Waconia cas Dabo ascetaion || y | QDI UUVTTOOOUIQUQUQQV0NUN0UEEUUT CULT WUIL TTNNUUUTEEUIIUNN ININNIII Ill IUNINUUUUUUIUUUUUUL iA WT | IIIII1 Il relace The object of this booklet is to present to the users of glass a standard or guide for the architect, owner or contractor, by which the material may be better known and more readily understood. It is the intention to briefly describe herein the more important and different kinds of glass for building purposes, with regard to adapta- bility for certain definite uses. It would be difficult, and perhaps impossible, to ade- quately describe or define technical differences to a certainty, either by written description or through the medium of printed illustrations. These suggestions, therefore, are sub- mitted with the hope that a careful reading will enable those who are to pass judgment to avoid the common errors which have invaded a field where no recognized authority has governed, and where abuses have often been permitted to appear in the absence of a strict and definite description of quality and kind. Glass blowing is as old as any other industry and dates back to the earliest periods of the world’s history, yet no general textbook on the selections of grades, or on the standardizing of the material has ever been issued in this country. It is not the intention here to cover every department of structural glass or to go into the exhaustive details of the artistic; but to confine the work to the everyday materials which are often thought so simple as to need no con- sideration. Three UUUHUHAUAAALUUULLLLLLELULLULUL LLU (AIA Re CR asacteegn |) | IUNNUUUUUUUUUUUHII Ill | TVNIINVUNVINNNNNNEH {NNN Plate Glass LATE glass can be made under the present improved HNN UUUNUUDOUUUUTOTEUULUUUUULUL il methods in extreme sizes up to 250 square feet and in such measurements as 10 feet by 21 feet (or 120’x 252”) containing 210 square feet—12 feet by 20 feet (or 144”x240”) containing 240 square feet—13 feet by 19 feet (or 156”x228”) containing 247 square feet. Such extraordinary glass is very difficult to make, quite expensive and dangerous SIZES AND, 2 donor Hindle ig tae a THICKNESSES ment when broken, requires special flat car shipment and special facilities for unloading and hauling, and the most expert and skilled glaziers in setting. Sizes are usually given in inches. It is advisable to confine sizes to the ordinary limitations in order to secure prompt and economical deliveries from distributors’ stocks. On account of the extraordinary demand for certain sizes of plate glass for stock sizes in mirrors, windshields for auto- mobiles, and stock door glazing, the proportionate production is below the consumption and a higher value is therefore placed upon these sizes, and their multiples. Polished plate glass is manufactured in thicknesses ranging from ¥” to 144”; THE STANDARD PRODUCT RUNS FROM 14" to 5/16” FULL. The other thicknesses (whether thicker or thinner) are made specially, and at an increased cost. THE SASH OR RABBET FOR REGULAR PLATE GLASS GLAZING SHOULD BE MADE TO ACCOM- MODATE GLASS FULL 5/16 OF AN INCH THICK. THICK PLATE 3// WAL 5/A! 3,7 Vall 1” 114,” 174% Glass thicker than the standard product is used for counter tops, deal plates, port and deck lights on ships, aquariums, etc. 14” to 5/16” One-eighth inch to three-sixteenth THIN PLATE 1473/:6” inch glass is used largely for residence windows and by car builders and for boat sash, automobile windshields; and for other special purposes where perfect surfaces, high polish, and absolute clear vision is wanted, with minimum weight. Notwithstanding the tremendous investment re- COST quired, the comprehensive machinery and materials used in manufacturing, the cost has been scientifically reduced so that plate glass is no longer considered a luxury and is every day increasing in popularity for general glaz- Four Ce National Glass Diseribulers ‘Association QTY TTOUVUUUNQNQQNNN0Q00000000UUU0 UU VIDE TYINVNQUVUITDDAIHNNT {uy ty Me Nacional Glass! Dixtrabitcery| syoctacion, | | INN PLATE GLASS (Continued) ing of high-class buildings, store-fronts, show-cases, for table and desk covering, dresser tops, chiffoniers, buffets, tabourets, shelves, etc. The use of plate glass adds an elegance and finish wherever it is seen. The cost of glazing buildings with plate glass is not prohibitive, and architects and builders will do well to make an intelligent comparison of figures and consider the enhanced value, beauty and dur- ability, accurate vision obtained in the use of plate glass. INNNIIAUUIINNNINNITL PUQILATUOUUUNNUQQUUUUUIOUNLNNITILE Ill IINNNQQNIUNIUAUUUUUUUUITII Ill Ill ne “tn aasan fusasaan au=s2a5 a= Clear vision afforded by the Distorted vision through the use of Plate Glass. ordinary window-glass. Polished plate glass should never be allowed to remain in packing cases longer CAUTION than necessary, as dampness may stain the surface. Whether boxed or open, glass should be kept on edge. Plate glass in regular glazing thickness (%”" to 5/16” thick) weighs 344 pounds per WEIGHT square foot bare and may be computed at approximately five pounds per square foot boxed for shipment. A rule for figur- ing shipping weight of plate glass is found in the official prict-list as follows: Extend the glass at 3144 pounds per square foot. Weight of box equals the contents of a plate of greatest width and length of those packed therein, multiplied by 10. Thus: 1 plate, 36”x96” ) 1 plate, 60”x84” | Size of box 60”x96”—40' x10 —400 _ _ pounds. 60614 pounds. See page 45 for table of net and gross weights of different thicknesses. —59’x314 —206%4 pounds. Five in Ge National Glass {VNNNNNQQUQUULUUUDUUUTUTNNI IN PLATE GLASS (Continued) Among the many who use glass there are so few who are familiar with its ingredients and its methods of produc- tion that we deem it fitting to describe some of the details of manufacturing the two principal products, and believe that a more familiar knowledge of plate and window glass will be both interesting and instructive. The raw materials may be said to be virtually the same in plate glass as in window glass—the main difference in the finished products being due to the great care exercised in selecting and purifying the ingredients, and the elaborate method of casting, grinding and polishing plate glass as com- pared to the simple and rapid process of producing window glass from blown cylinders. While both require skill and painstaking care on the part of the operator, the one will never equal the other in appear- ance or efficiency while the methods of production are so widely different. “Plate glass was first made in France in 1688 and the term “French Plate Glass” or “French Mirrors” has its origin from the development of the plate glass industry in France. The first cast plate made in the United States was produced in 1860 and perfected a few years later so that it may be noted that this is a modern product compared to window glass which was made during the early settlement of this country, at Jamestown, Va., about 1608. The making of ordinary glass has been included in the industries of almost every country in the world and dates back to ancient Egypt, centuries ago. {VNNIQVQUQUQUUCOYUOOTOUTT AUN TEHY AHN The _ principal INGREDIENTS ingredients are silica (white-sand) soda (soda-ash) and lime (lime-stone). Also arsenic, charcoal and cullet (broken glass). As stated before, the method of Las producing plate glass widely CS” differs from window glass Sh Sell and it is little known that the \ melting, casting, rolling, an- x nealing, grinding and polishing of plate involves the mining of silica and coal, the quarrying of limestone, the chemical manufac- ture of soda-ash on a large scale, the reduction and treatment of fire-clay and an elaborate system of pot-making for crucibles, all of which requires an Giess Dinibutey casocicion x IVNNNUINNUAIHUH I Ie arene Gitaks Oircantony eearccaeion ||| al l| PLATE GLASS (Continued) enormous financial investment, a multitude of men, and ex- tensive factory properties. It should be stated that the product of the American factories is, by comparison, equal in every way to the European plate glass in clearness, freedom from flaws and defects, homogeneousness and finish. IYVVUNUUANNNN {VVQQNQQUULLUUINNNNNNQ00U0LO00UUHNHNUT1 iil! PUHHALLULLUUUUUHHRLALLUULEUEHHAAAALIL Il III! h ki ta 1 Pte ee CIA OUALILY thicknesses, or superfine quality for mirrors or other uses where AND THICKNESS special glass is needed, requires special processes and entails additional expense in producing—and the making of beveled plates and mirrors necessitates two more elaborate lines of work and machinery and a corps of experts and skilled work- men. Pots of fire clay are such a heavy ex- pense in plate glass manufacture and take POT MAKING so important a part in the successful making of plate glass that the subject deserves special notice. The different clays after being mined are exposed to the weather for some time to bring about disintegration. At the proper stage finely sifted raw clay is mixed with coarse, burned clay and water. This reduces liability of shrinkage and cracking. It is then “pugged,” or kneaded in a mill; kept a long time (sometimes a year) in storage bins to ripen; and afterwards goes through the laborous process of “treading.” No machinery has thus far been invented by which the plasticity can be developed as does this primitive treading by the bare feet of men. The clay must be treaded many times. The building of the pots is a slow, tedious and time-killing affair; but this is essential. Without extreme care, some elements used in the mak- ing of the pots might be fused into glass while undergoing the intense heat of the furnace; or they might break in the handling, and much depends upon the strength of the pots. The average pot must hold about a ton of molten glass, and the average furnace heat necessary is about 3000 degrees Fahrenheit. After completion comes the proper drying out of the pots; and this is another feature in which the greatest scientific care is required. No pot may be used until it has been left to season for at least three months, and even a year is desirable. And after all this, the pot has but twenty-five days of usefulness. Seven A reacties ca ea ae | PLATE GLASS (Continued) The pot, having been first brought MELTING AND (to the necessary high temperature, is CASTING filled heaping full with its mixed “batch” of ground silica, soda, lime, cullet, etc. Melting reduces the bulk so much that the pot is filled three times before it contains a sufficient charge of metal. When the proper molten stage is reached the pot is lifted out of the furnace by a crane; is first carefully skimmed to remove surface impurities, and then carried overhead by an electric tramway to the casting table. This is a large, massive, flat table of iron, having as an attachment, a heavy iron roller, which covers the full width, and arranged so as to roll the entire length of the table. The sides of the table are fitted with adjustable strips which gauge the production of plates of different thickness. The pasty, or half- fluid glass metal is now poured upon the table from the pot, and the roller quickly passes over it, leaving a layer of uniform thick- ness. The heavy roller is now moved out of the way, and then by means of a stowing tool the red hot plate is shoved into an annealing oven or lehr. The plates remain for some time in the lehrs, where the temperature is gradually reduced. When the plate is taken from the annealing ovens it has a rough, opaque, almost undulating appearance on the sur- faces. Only the surface, however, for within it is clear as crystal. First, it is submitted for careful inspection, and then goes to the cutter who takes off the rough edges and squares it into the right dimensions; and thence to the grinding room. INUIT AVVUUUUVUULULLUUULUUILILL TVUUUUUUEUTUDOUUUUU0HQ00UUEEUEUOUUNN Illl ill Ill The grinding table is a large flat GRINDING AND revolving platform made of iron, POLISHING twenty-five feet or more in diameter. This table is prepared by being flooded with plaster of paris and water; then the glass is carefully lowered, and men mount upon the plate and tramp it into place Eight Ill INNNNNVTINVIVUUTUUAUULE Ill| kN EIR Cea | | PLATE GLASS (Continued) until it is set. After this, greater security is obtained by peg- ging with prepared wooden blocks; and the table is set in motion. The grinding is done by revolving runners. Sharp sand is fed upon the table, and a stream of water constantly flows over it. After the first cutting by the sand, emery is used in a similar manner. The plates are inspected after leaving the grinding room, and if scratches or defects are found they are marked. There are also, not infrequently, nicks and fractures found at this stage; and in such case the plate must again be cut and squared, or if the defects are too great, the plate is broken up for cullet. The polishing is done on another special table by means of special reciprocating machinery, using rouge, (iron peroxide), applied with water, and rubbing the glass with blocks of felt so arranged that every part of the plate is brought underneath the rubbing surface. The grinding and polishing has reduced the original plate half of its thickness, sometimes more. The material washed away is lost and fully half the original weight of lime and soda has vanished, and even at the completion, the inspectors very carefully scrutinize the glass for excessive defects and reject that which is not up to quality. New plate is sea-green, looking at GRADING AND the “metal” through the edge, which gradually fades when exposed for a QUALITY period to sunlight and weather, to a yellow or light brown color due to the action of the elements upon the chemical constituents of the glass. In the finished product (glazing quality) there may ap- pear some defects, which in no way impair the value, beauty, or durability of the glass for ordinary use—such as small seeds or bubbles, short-finish, reams or surface scratches, Nine UUHHHUAALLUALLULLLLLLUTLULULLUUUE EE ITNNNNQINUUUTNNUUNN 1S) Che National Glass Distributers Gsyociation TNVNNNUVUUUTULUUU Il TVNNNNQUOUULEUUQUQUUQNNNNUUUE LETT Hl nT: PLATE GLASS (Continued) which are accepted as contingent with the regular run of plate, and even an open bubble or shot-hole (not clear through both surfaces) is passed in standard glazing quality, providing the plate is comparatively free from other defects and of good color and finish. SPECIAL When glass of particular quality is desired, a special selection is necessary. This requires QUALITY an expert in the grading and selection of the material, sometimes necessitates cutting down larger sizes to minimize the amount of defects inherent with the regular production, and adds a proportionate extra cost to special quality plate. The beveling of plate glass is of such BEVELING interest and exemplifies such skill on the part of the workmen that a description of the process should be added to the information already written in the preceding chapter on plate glass. The glass to be beveled is subjected to treatment in different departments of the beveling plant, each division working out its particular process in taking off the bevel and restoring the surface of the glass to its original polish. Five divisions of skilled workmen are necessary; namely: roughers, emeriers, smoothers, white-wheelers and buffers (polishers) using different abrasive or polishing materials, such as sand or carborundum, emery, sand stone, pumice and rouge. The roughing-mill or wheel is a circular cast-iron disc having a fine cut corrugated surface about 30” in diameter, revolving rapidly upon its bearings as a horizontal plane. Sand or carborundum is conveyed to the mill from above through a hopper with a stream of water, so that the sand gives the desired roughness between the iron and the glass while the water minimizes the friction and heat. (1) The edge of the plate is brought into ROUGHING contact with the swiftly moving roughing wheel, and the sand cuts the bevel to the desired depth. Curved and pattern plates with incurves, mitres, etc., require an expert practiced eye and great skill on the part of the operator. (2) In the first rough- EMERYING ing process the beveled surface has been cut so déep by the coarse sand that it is necessary to follow with a finer abrasive in another mill to bring the bevel to a smoother finish, and emery or finer carborundum is used. SMOOTHING (3) Then the rough grinding is still fur- ther smoothed in the stone mill, or Ten INNNNIINNINIIIINH VVUUUUUULLLLUUUTTEHHUUELUUUULLLLLLL Ill Illl IN| (Che National Glass Distributers: syociation | PLATE GLASS (Continued) smoother, which is constructed upon the plan of the iron roughing wheel, using a circular revolving sandstone of fine texture with water flowing upon it to reduce friction. INNNNNNNNUUU00H1011 UVULUULUUULLUUULLUEULULULUULLLLI LL Ill ATV MimmSLLLLULUULUUUUULUUUULULUUULLLLLLLLLLLL (4) The first polishing process is upon a wood wheel in an upright position which POLISHING brings the bevel to a dull, milky polish by the use of pow- dered pumice in solution automatically splashed upon the wheel by a paddle. (5) The final high-gloss polish is put upon the beveled surface by the application of FINISHING rouge upon the upright polishing wheel which is covered with a layer of thick felt. REGULAR BEVEL 114” The standard width of bevel is 1a Th Caer | beveled plate glass or beveled plate mirrors are furnished with 114” bevel unless otherwise speci- fied. Slight scratches may be removed from the surface of plate glass by rubbing with pure thick felt mounted upon a hand-block, and using fine red or black rouge (moistened) as an abrasive. This must be skill- fully done to avoid over-polishing or “burning” the delicate annealed surface of the plate. The value of plate glass for GRINDING AND furniture tops, desks and tables, POLISHING EDGES show-cases, shelves and numer- ous other purposes has become generally recognized. The covering of glass with treated edges offers a clean, sanitary surface and an elegant appearance and also beautifies, protects and preserves the furniture. The process of grinding and polishing the edges, or rounding of corners, curves or pattern lines, is similar to the bevel- ing, except that the work is done on the te & edge of the plate instead of the surface. Pag Be? e The edge of the glass is rough ground according to specifications, either rounded or squared or chamfered as de- a it sired, and finished through the polishing g ie process—described in the previous chapter. Eleven IN| Ce Nacional Glass Distribucers Gyoctagon | ® Il PLATE GLASS (Continued) For decorative effects on WHEEL-CUT d : : oor-plates, side-lights, MITRED WORK transoms, partition-glass, etc., the rich effect of mitred design gives a tone of elegance, and emphasizes the beauty of the glass. The lines are cut V shape into the surface of the glass by a vertical wheel with sharp edges, and the smoothing and polishing is accomplished by the same general process as on the beveled edge. This is indentical in appearance and presents the richness and beauty of the finest cut tableware. Mitred designs on plate glass mirrors or on rolled figured glass produce an elegant effect where special and elaborate decoration is wanted. Mirrors HE silvered surface of a mirror magnifies and accentu- ates the qualities of the glass to a great degree; hence it is necessary to use the finest grade of plate to secure good mirrors. This selection of quality neces- sarily entails the most scrupulous care in making and selecting glass for mirror purposes. Every consideration must be given to both surface and general character, as the ordinary defects which would otherwise be unnoticed are sharply brought out by the cover- ing of silver. A The formula of the silver solution for SILVERING making mirrors varies but slightly with the different makers. The secret of success is in the process, and manner of treatment. Cleanli- ness is absolutely necessary. Chem- ically pure ingredients, distilled water and expert care with the proper facilities will produce mir- rors that will stand for years with- out deterioration, whether by the cold or hot method. After a thorough cleansing of the glass, removing all foreign substances from the surface, the “solution” is poured over the plate and by chemical precipitation a coat of pure silver is deposited. IUQVVUVOOUUUUUQUQUQVQN0H0000 TELL UT Hil DINNUUUNNIINNIINN Ill ie | Ce waganal Class Disodbuters' Cyecration | a HNN AHH MmLULLLLLLUULUULULLUUL OOS LE MIRRORS (Continued) This is permitted to dry and a preservative coating of shellac, with a coat of mirror-back paint completes the process. This is know as a patent-back mirror and is the standard highest grade. A method of making mirrors by mercury process was tested for years but found unsatisfactory from a commercial standpoint, and has become obsolete. Meee aren ante SIZES AND y by the sizes in which it is possible to make plate glass, THICKNESS and thin or heavy glass may be used as desired. It must be remembered that extreme sizes in strictly clear plate of mirror quality are difficult to obtain and necessarily carry some ordinary techinal defects, which cannot be entirely eliminated. The larger the glass the more likely these defects will appear. The common sheet-mirror or looking-glass used principally for the reflection of light rather SHOCKS than for the detailed image, is known to the trade as a “Shock- Mirror,” and is made from ordinary cylinder glass (window glass) and is very inferior in quality. Mirrors are susceptible to the PROPER effects of extreme cold or heat and INSTALLATION moisture, and should be mounted with proper protection against dampness. Care should be taken to avoid damp walls, or plaster which has not properly dried out, before installing mirrors. In glazing French doors with mirrors, or on Colonial work where small mullion glazing is specified, it is essential to have the panels absolutely upon a uniform line and rabbets of accurate depth as the mirrors will otherwise reflect at different angles and distorted vision result. A perfect effect may be obtained by using a back ground in large size mirror, and a false-mullion over all. Old mirrors which have become RESILVERING stained, spotted or peeled, may be re- silvered by carefully removing all traces OLD MIRRORS of the original backing and treating the glass as in the original silvering process. This is done at owner’s risk of breakage and restores only the silvering, while any defects or scratches in the glass will remain. Thirteen NVI TYNDIVIUUUUUTTTIOONEYNUNVINVNNNNQ0000011 NNN TVNLUNAUVUUUUHIUIII i Ce National Glass: Distributery Qyocration | ™ Window Glass E quality of window glass or sheet glass, also termed “blown” or “cylinder glass,” has been improved by the modern methods of production, and much has been expended in the effort to make perfect blown cylinder material. Yet there are still some waves and general defects accepted in all window glass, due to the process of making, which differs entirely from cast and polished plate. The glass is blown in cylinder form and flattened by reheating, which gives it a slight bend or bow, a possible variation in thickness in the larger sizes, and surface flaws. The selection of the various grades is a matter of ex- pert judgment. The large sheets produced, in single or double thickness and heavier, are cut to stock sizes according to the merits of the glass and graded in “AA”, “A” or “B” quality. The defects being eliminated to the greatest possible extent. The ingredients, as we have said, IANAUVQUUUUULUUUTHHAEUUCUUULLLLUHH IVUUUVULLLUUUTHHHHHELUUUUUELLLUU TE Ill = are practically the same in window glass as in plate— it is wholly a matter of refine- ment and process which produces the different kinds of material. Window glass— is made by two Blowing Cylinders by the human process— methods — by producing “Hand-Made” Window Glass. “machine” or by “hand.” The difference is in the blowing process—both producing the cylinder from which all window glass is evolved. The same general treatment of the cylinder, to produce flat sheet glass follows in both machine or human blown material, and both produce equally standard quality. To make the cylinder the molten glass or “metal” is brought to proper consistency by extreme heat, and the glass in the human blown process is “gathered” upon the end of a tube (cr blow-pipe) from the furnace and blown into a huge cylinder by repeated heatings and blowings, until the material is all evenly distributed. From a globular mass about the size of a man’s head, the blower swings the pipe into an alley or opening in the floor, blowing as he swings until the full sized cylinder is formed. This requires skill of the highest degree —the blower, by regulating the amount of material entering Fourteen im | Ge National Glass Distributors’ Gysoctation | | 8 WINDOW GLASS (Continued) the cylinder, makes single strength or double strength or heavier glass as desired. Ill A VVVHHUUAAEELULULLLLLLLLLULLLUCLUUULL IIll INUNNNNNU0000001UTUHUHL The blowing machine accomplishes the same result by purely mechanical process—the intricate working of the mechanism, the supply of molten glass, the air pressure, rapidity of action, making single or double thickness, being controlled by a single operator who appears to have super- natural powers, surely never dreamed of throughout the great stretch of years when the glass-blower was master of the art and accredited with inimitable skill. Ill Ill The cylinder is decapitated at both ends by an ingenious method of spinning a string of hot glass at the proper place, or by the use of a wire wrapped around the glass and elec- trically heated which causes the cap and crown to break off clean. The cylinder is then split lengthwise—placed in the flattening oven on a large circu- lar stone, and as the heat is in- creased and as the glass begins to wilt it is quick- ly smoothed out to the shape of the flat stone, up- on which it rests. Cylinder glass cannot be _per- fectly flattened, and the waviness and bow or slight curve will always s : Machine Blowing Factory—producing Window occur in this Glass Cylinders by Machinery. product. In glazing—-the bend or bow should be glazed outward in the sash—the bulge towards the exterior. Window glass in double strength, or heavier is made as large as 30”x90” or 38”x86” or 48’’x80” and SIZES such extreme sizes containing twenty-five square feet, but itis inadvisable to use such glass in these measurements on account of the liability of breakage and the distorted vision due to waves, etc. The same may be said of the extreme sizes of single strength which can be made up to 24”x60” or 30”x54” or 36”x50” in sizes containing ten to twelve and one-half sq. ft. Fifteen ca | WINDOW GLASS (Continued) The current “Jobbers Window Glass List” PRICE LIST gives full information regarding bracket sizes, list prices of all qualities and sizes in both single and double strength, in factory box lot, or by the light, and designates the number of lights per box in each size. (WN) UTNNNVINNITINNINN11 (VM UNVUUUUUTUTUUULH} VT mmm UULLUULULLUULUUUULERRLELLLLLLULLULC CRYSTAL SHEET A heavy blown glass, made by the same process as ordinary win- GLASS dow glass and subject to the same inherent defects. Graded in “AA”, “A” or “B” quality and made in various thicknesses: 26 ounce, 29 ounce, 34 ounce and 39 ounce (3/16” thick). In examining samples of small size for inspection of quality, it should be remembered that the large light of glass will show the natural waves and defects, while the small piece may appear nearly perfect. It is not altogether a matter of expert judgment to deter- mine the various grades and certain rules may be accepted governing window glass specifications. THICKNESS AND Single strength measures — ap- proximately twelve lights to the WEIGHT inch, but a small variation either way is permissable. Single strength weighs approximately 16 ounces to the square foot. Double strength measures approximately nine lights to the inch. The thickness should be fairly uniform and the weight approximately twenty-four ounces to the square foot. FACTORY £Window glass is packed in regular sizes PACKAGES approximately 50 square feet to the box up to the 100 united inch bracket (adding width and length), and 100 square feet to the box in sizes over 100 united inches. SHIPPING Single strength in factory packages weighs WEIGHTS from 65 to 75 pounds to the box (shipping weight). Double strength in factory packages weighs from 85 to 110 pounds to the box, 50 feet boxes, (shipping weight.) Double strength in 100 feet cases weighs approximately 225 pounds (shipping weight). “AA” OR FIRST “AA” quality should be clear glass, free from any perceptible amount of QUALITY air bubbles or blisters, burnt specks or burns, cords and strings. It should have a good gloss and an even surface and be well flattened. By air bubbles it is Sixteen WVU UUNNUNNINNNANNNNN0N TUN TUUUUUUUITUNUNNONNN000000000000000000UH1 , Ce National Class: Distributery, Qsyock WINDOW GLASS (Continued) understood that tiny blisters, or imperfections not percep- tible on the cutters’ table, but detectable when placing the sheet directly towards the light, would not be objectionable. This should be a careful selection in both single and double and should represent the very best that can be produced in window glass by the present methods. “A” glass is the normal selection “A” OR SECOND of glass when no special selection is desired or specified and it admits of ee such defects as small strings or lines, small blisters when not too close to one another or located in the center of the sheet. Well flattened, the surface even, and devoid of notice- able scratches, cropper marks, burns and other prominent defects. “B” glass covers a wider range than “RB” OR THIRD either “AA” quality or “A” quality. It permits many of the defects inherent QUALITY to the process of making such as waves, strings, lines, blisters, scratches, burns and other similar or equivalent defects. This quality embraces everything below “A” quality, not stony or full of blisters or other large defects objection- able for any common purpose, such as heavy scratches, heavy blisters, cords and sulphur stains. 26 OZ. CRYSTAL SHEET A cylinder or blown glass heavier than the ordinary Double Strength, and graded by the same rules as window glass in first, second or third quality, measuring approxi- mately 1%” in thickness (technically !*°/i090 of an inch.) 29 OZ. CRYSTAL SHEET A heavier blown cylinder glass, graded as above, (techni- cally 155/i999 of an inch in thickness.) 34 OZ. CRYSTAL SHEET A heavier blown cylinder glass, graded as above, (techni- cally '"/;999 of an inch in thickness.) 3/16” OR 39 OZ. CRYSTAL SHEET A heavier blown cylinder glass, graded as above, measur- ing 3/16” in thickness. Seventeen UVR LULLLUUUUUUUULUUULELLLLULLLLLLLL ULL TIN TUMUUUUUUUIILALNNNN iN) Ce National Glass: Distribucers Cssoctation | HNN NUNNVUIVUUVUUTHULE TNNY HQUDUQUVVNNUVUUEELUUUUUUVVVNNT0U THLE Bent Glass ENT Glass is artistic and attractive, and lends tone to the structure or building. Glass Bending requires special fur- naces, constructed similar to those used for annealing purposes, in Plate and Window Glass factories. The bending is done by placing a flat sheet of manufactured glass in a mould, made to fit the shape or radius wanted, and subjecting it to a temperature sufficient to allow the glass to soften and fall to the shape of the mould. It is then annealed, by careful process, the same as in the manufacture of Plate and Window Glass. The most popular sizes of Polished Plate Glass, used in Bent store-fronts, are 5614x96, up to 120” or longer, Bent to % Circle, on 363g” radius. Fre- quently there are calls for larger sizes, which can be bent as large as 140 wide x 120 high—to Quarter Circle, or part of width or bend made to a regular radius and balance straight. All kinds of glass can be bent, such as Polished Plate, Win- dow Glass, Rough, and Ribbed, Plain and 14” Wire Glass. Also Opalite, Vitro- lite and Carrara Glass, in all Thick- nesses for Wains- coating and curved Floor Cases. The shapes are shown in accompany- ing drawings. See opposite page for explanation. Eighteen UVVUOULUUUUELUULULLULUUELCLLULEULLLL QWNL UVIVNINNINNINNII11 cn HNNNUUIUAU IIIII ALLLULUUUATHTLLULELUOLGHHAA LAL UUUL Ill! BENT GLASS (Continued) A—Curves are those which are EXPLANATION bent to a given radius one way of the pane only, which applies to the OF CURVES AND DIAGRAMS whole length or width of the pane, and not to one part only. The depth of bend not to exceed one-eighth of the length of the bent side of pane. Example, length of the bent side of pane, 96”, depth of bend not above ae B—Curves are those which are bent more than one- eighth, but not to exceed the quarter of a circle, or about 1 in 514. Example, pane 77”, bend 14”. C—For the same curve as B, but a part flat, the flat part not to exceed one-third. Example, pane 72”, bend 48”, flat 24”. D—For flat curves, with one part flat, the depth of the bent part not to exceed 1 in 12, and the flat part one-half. Example, pane 72”, bend 36”, depth 3”, flat 36”. E—For curves, the bent part not less than a 6” radius, and not to exceed the quarter of a circle, with flat part, the flat part to exceed one-third but not to exceed two-thirds. Example, pane 72”, bend 24”, flat 48”. F—Curves are those which are bent beyond the quarter of the circle, but not to exceed 1 in 4. Example, pane 84”, depth 21”. G—For OG curves, depth not to exceed 1 in 16. Ex- ample, pane 64”, depth 4”. H—For angular curves, viz:—Flat parts on each side, the centers not to exceed a quarter of a circle, the end flat parts one-fourth of the sides bent. Example, pane 80”, bend 60”, flat 10”, each side, or about 5 one side and 15 on the other. J—For angle curves (radius not less than 6”) the center not to exceed the quarter circle, and the flat to exceed one- fourth, but not to exceed three-fourths. Example, pane 72”, bend 18”, flat 27” each side or about 14” on one side and 40” on the other. K—Curves are those which are bent beyond 1 in 4 but not to exceed the half circle (diameter not less than 12”). Example, pane 75”, depth about 24”. L—Curves not to exceed the quarter of a circle at each side (depth of bend not less than 6”), the bent part not less than one-third, and the flat not more than two-thirds. Ex- ample, pane 72”, bend 12” each side, center flat 48”. Specify width (measurement around curve) first, and then the height. Preferably submit pattern or template of sweep in all cases. Nineteen TTNNUQIQUVUQUQUQQUUTITUUVVVUUTHNHHNIN Ill IIIIII INIIVITNNNIIII Ill! iN Ge Wational Class: Distributery syoctagon | m Glazing HILE there is no uniformity in specifications govern- ing the method of glazing different styles of glass, it =—— is nevertheless advisable to call attention to some HWNLUITULUUUUUUNUNNNNN HNVVUTDUUUQQQQOTUQNQV00EUUUTULNVIUN cs IVVDUUUUUIQQQQVIVNNU00000UEUUUUTT tl zs Hil features which have been developed through the experience of the glass houses in this business. APPEAL TO It is especially desirable that all glass to be specified for a building be placed ARCHITECTS under one heading in the architect’s specifications under the heading—“Glass and Glazing.” Accuracy is a necessity. Use a standard rule, true to gauge; specify the size plainly. For instance, 56 inches might be confused if written 5’6”, and cut 66 inches—as 5 feet 6 inches. Always specify. width first. In measuring, it is advisable to allow a little play and measure inside the rabbet. See that rabbet is made to accommodate glass of the thick- ness ordered; i. e., order glass of proper thickness to fit rabbet. Measure the opening and see if all sides are squared, especially if metal work is to be glazed, it is essential to have perfect fit, and in large sizes it is not uncommon to find a warped frame, or not exactly square, slightly different at one side as compared with the other. Be specific—it is better to give an abundance of informa- tion rather than leave anything indefinite, or to be taken for granted. Mistakes will follow carelessness, and corrections involve loss of time and expense. Plate glass should rest on two pads of felt, leather, lead, oakum or soft wood blocks, one near each end, not against bare metal, or at a single bearing-point which might cause breakage through settling of building, vibration, etc. The soft wood blocks or lead strips are to be preferred. Do not fasten or bind glazing-mouldings too tight, as it is necessary to allow for expansion and contraction, vibra- tion and readjustment of construction. Use pure putty. Have sash-rabbet well oiled or painted so that putty will adhere. Give fresh putty glazing time to set before handling or hanging sash. Don’t try to back- putty glass with corrugated or figured surface, as the putty cannot be removed from the ridges in the glass. Steel sash glazing requires special putty for metal rabbets. CAUTION When glass of any kind has been delivered to a building packed in cases or with paper between the sheets, it is advisable to store the glass under cover in a dry place and unpack it to avoid stains which come from drying out of damp hay, straw, paper, or other pack- ing materials. Twenty HNN UUUUUUUUUUUUUUUUINNI QNIY TUNNVVUVIQVN00N00N000 0000000000000 GLAZING (Continued) Glaze prism-glass with ribs inside—flat surface outside. Regular glazing is done with uncolored putty. If colored putty is desired it should be specified accordingly. Glass is not bedded-in-putty or back-puttied unless specially ordered or specified. Window glass is regularly glazed with the natural bow or bend outside. Metal Store Front Construction = =—HE setting of plate glass in store fronts has been the subject of a great deal of consideration on the part of architects and builders. The desire to eliminate massive bars, heavy sills and obstructing frame-work has brought into the market many kinds of devices for build- ing show-cases and store windows which present the maxi- mum display of merchandise to the public, and at the same time insure safety and rigidity of construction. See erie COs NT EATS TORE: FRONT bars, division bars and sills CONSTRUCTION and the all-glass show-case is marked by the absence of bulky posts or ponderous frames. There are several standard makes of metal store-front construction, corner-bars, dividing bars, metal sill, etc., which fasten or secure, the glass with a metal locking or clamping member and provide for drainage, ventilation and illumination if desired, which may be obtained from the various members of the National Glass Distributers’ Association. Twenty-one ITN TDQIQIQUUTUUUUUONUUNNNQNVNNNNVNNUUUU0U | Ge Nacional Glass Distributery’ Association, | INN TINLUUUAUUTUUUUINNI (1M UUNNVINVULUUUUUAULL HNN UVNNVDEUUUQVGVOOOUUUUHNV0ELETUUNATE METAL STORE FRONT CONSTRUCTION (Continued) We do not enter the brands of the several standard makes or recommend any special style of store-front construction, but it is well to make comparisons, giving attention to the necessity of substantial strength in the retaining members, and using metal bars and construction of sufficient weight to insure strength and rigidity. It is advisable to send working drawings or detailed plans of store fronts—and the utmost care should be exercised in furnishing accurate dimensions when ordering, so that a true fit of metal may be assured, and proper allowance made for bearing contact or play of glass. The architect should make definite specifications as to the material desired, giving names or numbers of bars, sill covering, jamb bars, jamb covering, transom bars, transom covering, style of metal finish, etc. All-Glass Patent Fronts ALL GLASS CLAMP Tri we i et STORE FRONTS w no special recommendation to those who have examined it, and the unobstructed view of the display as well as the continuous glass effect has made it a popular and attractive model for retail stores through- out the United States. Twenty-two {HNL UUDDTOLOUUQUQUNVONNQNVUUUETEUUUETIIVT INN UINVNVNNNVNTNN00001 Itltl 1 1 TTLLUDUATAN Hi VHHULUUULUUHUHALLLULLUUUUHHALLL LEE y IN | | separated for special treatment in detail. Under the head of Leaded Glass there are multitudes of sug- gestions for every artistic emotion, and this is a subject for the expert and depends upon individual taste. That which is considered beautiful and harmonious in line and tone expressing the ideal of refinement to some, may be rated without merit or attractiveness by others, so we leave the technical artistic side of this branch of the industry and give a few suggestions and practical points of information. Leaded Glass—without color, should be specified “Clear Leaded” or “Obscure Leaded.” If some particular design is selected from catalogue, give name and catalogue number and the number designating the design. If special designs are wanted for some particular work, give description of general architectural lines, decorative scheme, etc. All leaded work is made especially to order to sizes desired, therefore place the order giving ample time to the manufacturer to produce the windows without undue haste. For odd shapes or odd sizes send patterns. Give the fullest possible description with rough sketch showing grouping of window openings or any information that will assist the artist in detailing the designs. or a transom or landscape window, 40”x18” 40 Specify width first— for instance:— an upright window, 18”x40” Odd or fractional parts of inches are charged as even inches of next higher size—for example 2644”x2714” is figured as 28”x28”. Circles or odd shapes are charged at the full square out- side measurement. To obtain rigid construction specify metal-set work, especially for doors, pivot swinging sash, etc. On account of the weight, beveled plate, heavy orna- mental glass, and thick material such as prism is usually specified set in metal—either plain zinc or copper plated. All leaded glass of sufficient size is reinforced with steel strengthening bars. Glaze leaded glass or metal set glass with steel stiffening bars inside. Twenty-three Tall TIANA II | LVN TDMULUDUIUVINNNINTL . Wire Glass AVM UULALLULULUULUULLUUUUULEELELLELLLL LLL proof construction has increased the demand for wire glass until the production of the material amounts to == millions of square feet annually. Not only does this glass minimize the fire-hazard, but its resisting and sustaining strength, its unyielding qualities even when cracked make it the logical glass for skylights, elevator shafts, stair-wells, etc., where these features are a consideration. ——— use of metal frames, metal window sash and fire- Wire glass is made by three methods: METHODS OF 1. (Shuman process) by _ rolling MAKING a sheet of glass laying the wire mesh upon it while the glass is still plastic, pressing the wire-netting into the glass, and by a coincident process smoothing the surfaces. 2. (Appert or Schmertz process) by rolling a thin sheet of glass and laying the wire-mesh upon it and simultaneously pouring and rolling a second sheet of glass on top, imbedding the wire. 3. (Continuous or Solid process) by mechanically crimping the wire netting and placing same on the casting table and pouring and rolling the glass over it to produce a sheet of wire glass. The introduction of the manufacture of wire-glass is of so recent a date as to make the volume of consumption all the more surprising, especially when it is recalled that the product was comparatively unknown twenty years ago. STANDARD Wire shes is made in ues as large 60” wide and 130” long and in THICKNESS 4" several thicknesses—lYy4”_ standard thickness for general use and approved by the National Board of Fire Underwriters. Thinner wire glass is obtainable— OTHER 3/16” and 14%” being made for special THICKNESSES purposes, but the universal demand is for 4” or 3%” or heavier, and no wire glass less than 14” thick is accepted under the rules of the Fire Prevention Bureaus or the National Board of Fire Underwriters. It is necessary to follow certain UNDERWRITERS’ rules and regulations in the making REQUIREMENTS of fire-proof windows and construc- tion, as provided by the National Fire Protection Associa- tion, and a copy of the requirements of the National Board of Fire Underwriters may be obtained from any member of The National Glass Distributers Association. Twenty-four HTN TUTUUUOUUUUUUINNVVUN0UUUEELLUOUUVUNN < | Che Nation Chass Dierabcers asoctatio|\ INIT) YVNVNINNTUNUNEU111 i) ke Ween ay Ditbuders| accion WIRE GLASS (Continued) TNNQNNNUVTLALUUANN Extract from Rules and Requirements of the National Board of Fire Underwriters, Edition of 1906. Ill! IVUALULUUUUUUUUTHHHLULLUUUUULLLUUEE HUUVEUVLUUUUUVLUUULLUELLUUULLLL LLL I Ill THICKNESS OF GLASS: Wire glass to havea thick- ness of at least 14 of an inch at the thinest point. SIZE OF GLASS: The unsupported surface of the glass allowed, shall be governed by the severity of exposure and be determined in each case by the Underwriters having jurisdiction, but in no case shall it be more than 48 inches in either dimension or exceed 720 square inches. Windows, doors and partitions should be specified for such sizes as 15’’x48”, 18”x40”, 20”x36” and 24”x30” to con- form to the above rule where dimensions are not to exceed 720 square inches. There are also restrictions and regulations governing the depth of rabbet (34” deep) bearing of glass (54") and style of metal frames and sash to meet the demands of fire-retardent construction and permit reglazing, etc. F Myre ee is peace NS rolled POLISHED rough” or “ribbed” or “figured” patterns, and when ground and polished for clearer WIRE GLASS transparent vision, is specified under the term:—‘‘Polished Wire Glass.” This is not the quality of clear polished plate, but a polished rough wire glass, with the ordinary run of defects inherent with rough glass which has polished surfaces. Width POLISHED WIRE GLASS Twenty-five ly TL mm LLLLLULULUVHALLL HNN UVVTEVVTUOOVUUUUUAUUUUUIUUTUINNTVININ | | Ae neceenial Cila) Daserebiney Cimneceagion||| WIRE GLASS (Continued) Width Width ROUGH WIRE GLASS MAZE WIRE GLASS COLONIAL WIRE GLASS The twist of the wire runs with the length of the sheet, and should be set vertically. In ordering always specify width first. Stock Sheets, packed in cases containing 350 to 500 square feet in any regular even inch width. See page 45 for table of maximum widths and lengths, approximate weights, etc. Twenty-six . HNN) UUDUUUUUUQUUQUVUVQNN00TTEELUUUIUNN / INN UVUUUUUUUUUNNNVUNN | | Ce Nationa Ces Disitaers Casoctation, | ATILNNNIULUNULNVNLINNIT} II] ' MOSS WIRE GLASS SYENITE WIRE GLASS ea. . rt Width Width ROMANESQUE WIRE MURANESE WIRE GLASS GLASS The twist of the wire runs with the length of the sheet, and should be set vertically. In ordering always specify width first. Stock Sheets, packed in cases containing 350 to 500 square feet in any regular even inch width. See page 45 for table of maximum widths and lengths, approximate weights, etc. Twenty-seven HV mm LUUAULULULULLLLLUL UVR TTTHNALUUULUULLULUTHHHHUUECCU LL WIRE GLASS (Continued) Width SOREN FLORENTINE WIRE GLASS LIBERTY WIRE GLASS Width Width PENTECOR WIRE GLASS AQUEDUCT WIRE GLASS The twist of the wire runs with the length of the sheet, and should be set vertically. In ordering always specify width first. Stock Sheets, packed in cases containing 850 to 500 square feet in any regular even inch width. See page 45 for table of maximum widths and lengths, approximate weights, etc. Twenty-eight UT UUTUUUULLLLLETHUULULLLLAE ELL IR ea INN TIUUUUDIUNNINNUU1 (8 Ce National Class Distributers @ssoctation | ™ Rolled Figured Glass HE prime object of figured glass is to supply an obscure translucent glazing material with attractive pattern of depth and character, and at the same time it must be essentially prismatic so as to admit, diffuse, and distribute the light. QUUL THMUUUULUUUULNNNNN YUL SUVYVVUNTNVUNVV0N00000 0000000000000 Fu INN TUUUIUUUUUUUUUUITII HNN UUQNNUUQU00000FUTEUEEUUUUUUUUAUUULIALE FLORENTINE GLASS SYENITE GLASS MOSS GLASS Sizes up to 48” wide and 182” long. Thicknesses 4%”, 3/16”