v i I ^ "oO N - ^ .*<* .• y* .& #'% A PRACTICAL TREATISE ON COMPRESSED AIR AND PNEUMATIC MACHINERY BY EDWARD A. R1X AND A. E. CHODZKO PNEUMATIC ENGINEERS FOR THE X -FULTON Engineering ^ Shipbuilding Works SAN FRANCISCO MANUFACTURERS OF MINING, MILLING, SMELTING AND ELECTRICAL MACHINERY ENGINES, BOILERS, HEATERS, PUMPS, ETC. Main Office and Branch Works, 213 First St. Main Works, Harbor View SAN FRANCISCO, CALIFORNIA L9373 Curves, Tables and Engineering Data in the body of this Treatise are original and were prepared by EDWARD A. R1X AND A. E. CHODZKO PNEUMATIC ENGINEERS San Francisco, - California Entered according- to Act of Congress, in the year 1896, by THE FULTON ENGINEERING AND SHIPBUILDING WORKS AND EDWARD A. RIX In the Office of the Librarian of Congress, at Washington, D. C COMPRESSED AIR. It is a noteworthy fact that, while compressed air has been ;wn and been used at a time when dynamic electricity was even in its infancy, its properties and possibilities are still, he minds of many practical people, an object shrouded with confusion and mystery, and considered by them as a convenient topic for the scientist's investigation, but altogether too intri- cate and obscure to be readily grasped by a man possessed of a common and average knowledge of motive machinery. This same man, strange to say, will find no apparent mys- tery in handling a first-class Compound Condensing Steam Engine, whose thorough comprehension, however, involves a more imposing array of natural phenomena than does the action of an air motor. Mention to him this latter machine, and he will tell you at once that it is useless; he has a vague recollection that com- pressed air will not yield over 15 to 20 per cent of the power expended to produce it, while an electric motor utilizes 60 or 80 per cent of this power, and that is the end of it. The fact is, however, without in any way disparaging the wonderful strides made by electricity, that, in a great many circumstances, a compressed air power transmission will be found fully as much, and often more effective than an electrical transmission. Within a radius of 10 to 20 miles or more, it is not a matter of theoretical speculation, but a result of actual facts, extend- ing over a period of many years' experience, that compressed air can be economically produced, conveyed, and utilized as a motive power; and if this power is to be distributed through- out a number of buildings or factories, or in the interior of a mine, the absolute safety consistent with the use of compressed air is an element of superiority to which the electrical trans- mission has no possible claim. However well insulated thexonductors may be, the vicinity of a dynamo is always dangerous, either on the ground of fire or of bodily injury. In a large power station, manned by a picked staff of attend- ants, this danger is small indeed; but the conditions are alto- gether different if the motor is under the care of a miner or of an ordinary workman. Again, the location of an air motor is privileged with a con- stantly renewed and wholesome atmosphere, whose tempera- ture can be, at will, regulated to suit the local exigencies. Accidental circumstances which may occur in the vicinity of an electric wire under high potential are generally fraught with peril. The only accident to which an air pipe is liable is 4 COMPRESSED AIR. a leak, which will cause a loss of power, but which cau be re- paired and approached at no risk whatever. But now conies another point. Referring more especially to the mines which, in California, should represent a large percentage of the users of compressed air, an example will well illustrate the comparative merits of the two modes of power transmission, especially for mines. Take a mine which was equipped some years ago; ample water power exists several miles away, but the configuration of the ground did not permit of conveying the water to the mine; a telodynamic transmission would not have been practi- cal, so the owners concluded to put up a first-class steam plant for hoisting, pumping, and milling purposes, and also for run- ning compressors supplying air to the rock drills, and perhaps to one or more underground pumps and fans. In the course of time, however, timber has grown scarce in the surrounding sections, and now they have to haul their fire- wood at the rate of $5.00 or $6.00 a cord; as there is quite an amount of power used at the mine, this represents a rather burdensome item, so the owners begin to investigate some pos- sible way out of it. An electrical transmission is forthwith proposed to them, with tangential wheels and generators near the waterfall, con- ductors readily spanning all the intervening ridges and can- yons, and a number of dynamos to replace the steam engines. It is a practical, feasible, and satisfactory proposition, but there is one black cloud in this bright sky: what shall become of the steam engines and boilers.? They have to be torn down, of course, to make room for the dynamos. This whole plant is still, however, in perfect condition; it has been bought, hauled, and erected at great cost, and would bring, at a sale, about as much as its equivalent of scrap iron, supposing it could be sold at all. The proposed plant will assuredly be more economical, but this is a dead loss which it will take some time to make up for. Here comes the opportunity of the compressed-air man; he proposes to put up an air-compressing plant at the water-fall; the iron-pipe that carries the air will span ridges and canyons as easily, for all practical purposes, as did the wires, but after it reaches the mine, the list of new material closes, or nearly so; for neither the engines nor the boilers will have to be touched. The former will v/ork with air as they did before with steam, the boilers being used for heaters or air receivers. The compressor that used to work at the mine will not even have to be discarded, as it may serve either as a reserve or as a pressure transformer; in other words, there will have been an addition to the mine's possessions, in the shape of the com- pressors at the power-house and of the pipes, but the old plant will remain just as it was, and give full value for what it did cost; it will simply be necessary to find a new job for the fire- men and woodchoppers. Another very important point: suppose the power plant at COMPRESSED AIR. 5 the water-fall met with accident, or the conductors to be tem- porarily crippled; with the electric plant it means a stoppage of the whole mine; with the compressed air proposition it would only be necessary to fill the boilers, start up the fires, and run by steam again. Here, there is no possible competition between the two systems. The advocates for electricity claim a superior economy, but a few developments on the production and the utilization of compressed air will, it is hoped, prove to the con- trary, and we will try to illustrate the laws and properties of air and compressed air in a simple manner, and with the constant remembrance that practical men want plain facts and have no use for mathematical discussions. It is a common feature with gaseous substances that heat has a tendency to increase their volume, or, as the term goes, to expand them. Referring more particularly to atmospheric air, it will suffice to recall the classical experiment of the cork shutting hermetically a bottle full of air, and blown out, if the bottle be dipped in hot water. Therefore, if a certain amount of air is confined within a closed cylinder, at the outside temperature, and then exposed to a source of heat, this air will have a tendency to expand, the result of which may be twofold. If the cylinder is closed, for instance, by two covers tightly bolted on, and if its walls and covers are strong enough to resist deformation under this expansive tendency, the volume of air will remain constant, and its pressure will increase. But if we suppose that one of the covers be removed, and replaced by a tight-fitting piston free to move in the cylin- der, and loaded with a certain weight, when the air is at the outside temperature, the piston will descend in the cylinder until it is balanced by the pressure of the confined cushion of air. If now the cylinder is heated, the piston will start slowly upward, and then stop when the expansion wall have ceased; in this case, the load of the piston, and consequently the pres- sure of the air, have remained the same as before heating, but the volume of air has increased. Summing up these simple facts, we will say, therefore, that the effect of heat upon this mass of air is, in the first cfse, to increase its pressure under constant volume; and in the second case, to increase its volume under constant pressure. The reverse w 7 ould happen in both cases; i. e., if we take the closed cylinder full of hot air, and if we allow it to cool down to the outside tem- perature, the volume of this air will, of course, remain the same, but its pressure will fall gradually, until it becomes the same as it was before heating. In a similar way, if we allow the cylinder with its piston to cool down to the outside temperature, the volume of air con- fined under the piston will shrink, and the piston will grad- ually drop down to the point where it was before the cylinder was heated, the pressure, of course, remaining constant. Now, following this line of reasoning, we may conceive 6 COMPRESSED AIR. that, if the temperature arouud the cylinder was made colder and colder, the pressure of the constant volume of air of the first case would keep dropping, and the volume of the mass of air at constant pressure, in the second case, would also keep shrinking, until, if such a process was carried on far enough, the mass of air which we have been considering would be con- densed in volume to nothing, and have no pressure at all. A simple calculation shows that such a result would occur at the temperature of 461 degrees below o Fahr., or 493 degrees below the freezing point of water. This temperature, which has been approached, but never yet reached by any contrivance at present at our command, is, so far, a matter of mental conception, but we may, however, conceive its existence. It is called the absolute zero, and plays an important part in the study of the properties of gases. The absolute zero is, therefore, the temperature at which a mass of air would have neither volume nor pressure. Passing now to a seemingly different subject, although its close connection to the preceding facts will soon appear, a few words may be said about the fundamental principle which forms the basis of all questions relating to the mechanics of gases, the Principle of Equivalence of Heat and Work. This principle, formulated in plain language, means that whenever work is performed, it develops heat; and conversely, that -whenever heat is generated, it can be traneformed into work. The scope of this principle is exceedingly broad. The elementary conception of work involves two distinct elements: a force and a motion, and the measure of the amount of work developed by a certain force is the product of this force, multiplied by its displacement. Thus, if we exert a pull of 1 lb., and if we move 1 foot in the direction of this pull, the work that we have developed amounts to i-foot pound. But, while this definition is true in all cases, work, in nat- ural phenomena, can assume a very great variety of forms, which, moreover, it is not necessary to enumerate here. Our daily experience shows us some applications of this principle of equivalence, or correspondence, between heat and work. That work develops heat, we can see in hammering a cold bar of iron, which soon becomes hot; we see it in the result of human exertion, in the heating of a shaft journal when the work of friction becomes too great; in the sparks showing at the contact of a revolving wheel, and of a brake-shoe, or at the periphery of a grindstone, etc. That heat can be transformed into work has been shown in the preceding explanations, when we saw a weighted piston lifted by heating the air confined beneath it. ' The steam engine is another indirect demonstration ot the same fact; when the heat developed in the combustion of coal generates steam, which accomplishes some work on the piston of an engine. COMPRESSKD AIR. 7 It would be useless to multiply examples of this capital principle; suffice it to say, that whenever work is performed, there is a production of heat. This will not always be sensible, especially if the work is slow and gradual, because the heat is lost by radiation, by absorption in surrounding bodies, etc., as soon as it is developed. This subject of the equivalence between heat and work has been exhaustively studied and verified, and it is now accepted as a fundamental axiom in mechanics. One British Thermal Unit (B. T. U.) of heat, i. e., the quan- tity of heat required to raise by 1 degree Fahr. the tempera- ture of I lb. of water, corresponds to 77 8-foot lbs. of work. In other words, 778-foot lbs. of work applied to a certain mass of air, for instance, will develop in it 1 B. T. U. of heat; and conversely, an amount of heat of 1 B. T. U. stored up in this air can develop 778-foot lbs, of work. The number 778, or coefficient of correspondence between heat and work, is known as the Joule's Equivalent, from the name of the physicist who first set precise rules in this respect. Joule had fixed the figure at 772-foot lbs., which was for years adopted as correct. Subsequent investigation led to make it 778, and the most recent developments put it at 779. In this treatise it has been taken as 778. But it is now expedient to clearly explain how a certain mass of air, which has been subjected to work, and which has therefore accumulated a certain amount of heat, can conversely develop work corresponding to that heat. Let us take a cylinder full of air at atmospheric pressure, and closed at one end, and then let us insert at the other end a piston in this cylinder, and exert an effort upon the piston; the air confined within the cylinder will be gradually com- pressed, and occupy a smaller volume. At the same time, its pressure will have increased, and this compression has absorbed a certain amount of work, which will be measured by the mean pressure which the piston has had to overcome, multiplied by the amount of its displacement. The pressure on the piston represents a certain number of lbs.; the displacement represents a certain number of feet, and their product represents a certain number of foot-lbs., which measure the work of compression. Suppose now that we release the piston; the air confined in the cylinder, and whose pressure was solely owing to the effort exerted on this piston, will immediately expand and push it back, and if there was no friction between it and the cylinder walls, it would resume its former position, when the air-cushion would be at atmospheric pressure again. In other words, every amount of work spent in compressing the air, would be entirely returned by the expansion of this air, or, to any work of compression corresponds an equal ivork of expansion, if these efforts follow each other instantly. Here, we did not make any assumption as to the tempera- ture of the confined air, which has been supposed to remain 8 COMPRESSED AIR. stationary. But now let us confine, with a piston, a certain amount of free air in a cylinder, and let us fix the piston in this position so as to prevent it from backing out; and, then, let us apply to the cylinder some source of heat. The confined air will have a tendency to expand, and as the piston cannot move, the pressure will rise; if then we let the piston free, the confined air will push it out in expanding, until it resumes the atmospheric pressure, and the outside tem- perature, and with the same restriction as regards frictional resistances. We see that in both instances there has been some expan- sive work done, and the force that produced it was supplied in the first case by the work of compression, and in the second case, by the heating of the air. We see also that in this latter instance, the pressure of air in the cylinder depended upon the amount of heat supplied to it, or, in other words, upon its tem- perature, and so did the expansion work. Returning now to the definition of the absolute zero, as given, which marks, so to say, the ideal limit of existence of a gas so far as volume and pressure are concerned, we can readily conceive that I lb. of atmospheric air, at 60 degrees Fahr., for instance, is the outcome of 1 lb. of air at the tempera- ture of absolute zero, to which a sufficient amount of heat has been supplied to raise its temperature by 461 +60=521 degrees Fahr., and its pressure to 14.7 lbs. per square inch, above a vacuum, wliich is the pressure at the absolute zero. This pound of air is confined within the atmosphere, as was the mass of air of the last example within a cylinder; but should it be allowed to expand against a perfect vacuum, it would produce an amount of expansion work corresponding to the amount of heat which it had received to become atmos- pheric air. This capacity of producing expansion work is what is termed the Intrinsic energy of this pound of air, and its exist- ence is, as we see, intimately connected with the conception of the absolute zero. The amount of work that measures this intrinsic energy can be determined from the law of the equivalence of heat and work, since we know that by storing up a certain quantity of heat in a mass of air, we give it the property of returning a corresponding quantity of work. The temperature to which a given amount of heat will raise 1 lb. of different substances is not the same for all of them. The specific heat of a substance is the number of B. T. U. that will raise by 1 degree Fahr. the temperature of 1 lb. of this substance, the specific heat of water being taken as unit. We have seen already that the specific heat of water was 1 ; i. e., that it takes 1 B. T. U. to raise by 1 degree Fahrenheit the temperature of 1 lb. of water. The specific heat of air which we have to use in the subse- quent developments is 0.2377. In other words, it takes 0.2377 of a B. T. U. to raise by 1 COMPRESSED AIR. 9 degree the temperature of 1 lb. of air, that is to say, the amount of heat that would raise by 1 degree Fahr. the tem- perature of 1 lb. of water, will raise by 1 degree Fahr. the temperature of 4.2 lbs. of air. The quantity of heat necessary to raise by 521 degrees Fahr. the temperature of 1 lb. of air is, therefore: 0-2377X521=123.8412 B. T. U., and the corresponding amount of work is, 123.8412x778=96,348.52 foot lbs., which represents the Intrinsic energy of 1 lb. of air at 60 de grees Fahr. This, of course, presumes that no heat would be either lost or gained, by radiation or otherwise, during the expansion of air, and this sort of expansion is called Aiiabatic expansion. Now, while any one will readily understand that the expan- sion of air can be utilized to do useful work on a piston, it is also obvious, for practical reasons, that this expansion cannot be carried below atmospheric pressure, since creating a vacuum would require additional work. Consequently, we cannot expect to avail ourselves of any portion of the intrinsic energy stored up in atmospheric air, under ordinary circumstances. With a steam engine wecan obtain a vacuum, or at least a pressure inferior to the atmosphere, by condensing the steam, but there is no such thing in the air machine. Let us observe, moreover, that the intrinsic energy pos- sessed by 1 lb. of air is entirely independent of its pressure, so long as its temperature remains the same, the work of expan- sion being exclusively controlled by the extreme temperatures between which the air expands; so that 1 lb. of air at 100 lbs. gauge pressure, and 1 lb. of air at 10 lbs. gauge pressure, and both at 60 degrees Fahr., possess the same total intrinsic energy as 1 lb. of atmospheric air. But there is a vast difference between them at a practical standpoint, inasmuch as air at 100 lbs., and even at to lbs., can do some useful work by expanding down to atmospheric pres- sure; part of their intrinsic energy can, therefore, be utilized to do some actual work. Taking, for instance, 1 lb. of air at 100 lbs. gauge, and at 60 degrees Fahr. — if allowed to expand adiabatically to atmos- pheric pressure, it will produce work, and consequently lose part of its heat, and we find that its temperature, after the expansion has taken place, is: — 173.95 degrees Fahr. The drop of temperature is: 173-9^+60=233 95 degrees, and as 778x0.2377=184 93, the work of adiabatic expansion is: 184.93x233-95= 43,264.37 ft. lbs. this being the useful work, The adiabatic work of expansion from 173. 95 degrees Fahrenheit to the absolute o would be: 18493X287.05= 53,084.15 " " Total, 96,348.52 " ' COMPRESSED AIR. COMPRESSED AIR. II which is the total intrinsic energy — that is to say, we have utilized 45 per cent of the total intrinsic energy. Next, taking air at 10 lbs. gauge, the temperature after adia- batic expansion to atmospheric pressure is — 12.9 degrees Fahr. , and the useful work of expansion is: 184.93x72.9= 13,481.39 ft. lbs. The adiabatic expansion from — 12.9 degrees to absolute zero would give: 184.93x448.1= 82,867.13 " " Total, 96,348.52 " <( i. e., the total intrinsic energy, and the useful work is here 14 per cent of the total intrinsic energy. It is hardly necessary to say that these figures are theoreti- cal, because, in practise, part of the work of expansion, and consequently part of the heat, is absorbed by the friction of the piston in the cylinder, and lost by radiation from the vari- ous pieces of the machines. We see, therefore, that the only portion of the intrinsic energy of air that is practically obtainable is the expansion work which it does above atmospheric pressure; i. e., that the pressure of this air must be raised above the pressure of the atmosphere. From the preceding developments we might rightly con- clude that this result would be reached by heating the air, previously confined within a closed vessel, to a proper temper- ature. But in practise, such a process would prove unaccept- able. Compressed air is slow in taking up heat, because its con- ductivity is small ; i. e. , because the heat is slow to penetrate the whole mass of air, and its low specific heat causes it to cool down rapidly. Then, again, the whole amount of expansive work above atmospheric pressure could not, as said before, be obtained in practise; so that raising the pressure of air by mere heating is not a practical proposition, and it is necessary, in order to meet the requirements of its industrial applications, to operate this rise of pressure by direct compression; i. e., by acting upon the air, confined in a cylinder, through a piston to which an adequate amount of power is applied. This compression, in whichever way the rise of pressure occurs during its process, is always affected on the following general lines: A cylinder A (Fig. 1), closed at both ends by covers, con- tains a piston B, which can move back and forth therein, and whose rod C is connected, either to the piston of a steam engine, or, through a connecting-rod and a crank, to a revolv- ing shaft. Kach one of the cylinder covers carries one or more inlet valves a, a f , through which the atmospheric air can penetrate into the cylinder; each valve, of course, opening inward, and being maintained tightly pressed upon its seat by a spring. 12 COMPRESSED AIR. The covers also carry one or more discharge valves C 67, similarly kept closed by a spring, and opening outward into closed chambers g, k, connected by a common conduit c, which leads to a closed receiver r, whence a pipe attached to the nozzle s, conveys the air to the place where it is proposed to use it. All the valves being closed, and the piston B at one end of its stroke, as shown, if it is set in motion from the left to the right, a partial and increasing fall of air pressure will occur behind it, and soon overcome the tension of the spring which keeps the inlet valve a closed; this valve opens, and atmos- pheric air rushes into the cylinder, behind the receding piston. On the right side of this latter, we have, at the beginning of the stroke, a cylinder full of atmospheric, or, as generally called, of free air; the inlet valve a, and discharge valve b, are both closed, and so remain as the piston moves from left to right, because the air pressure in the cylinder has a tendency to close the inlet valve a\ whilst its pressure is not sufficient to lift the discharge valve b' '. The piston continuing to move, the air pressure constantly increases, until, at a certain point n, of the stroke it reaches, or slightly surpasses, the receiver pressure. The action of this latter on the outerside of the discharge valve b' , and also the tension of its spring are now balanced, and the smallest subsequent move of the piston opens this valve, and the compressed air is forced through it into the receiver, until the piston reaches the end of its stroke, when the discharge valve is closed by its spring. An inverse series of operations will occur during the reverse stroke, and so on. An analysis of these operations shows that during any one stroke of the piston there are three distinct classes of work per- formed: on one side of the piston, a work of suction; on the other side, first a work of compression, under variable piston load, and then a work of delivery, under constant piston load. This is quite similar, only in the reverse order, to what occurs in the cylinder of a steam engine, wherein a certain volume of steam is admitted under full pressure, and then, after cutting off its ingress, is allowed to expand during the remainder of the stroke. The work of suction, which overcomes the inertia of the in- let valves, the tension of their springs, and the resistance of air in its passage through the valve apertures, is always small, and can be reduced by properly proportioning and constructing the inlet valves. It is, therefore, a matter of correct design, which has nothing to do in the present developments, and no further mention of it will hereafter be made. Of the two other qualities of work, the peiiod of delivery does not either offer any peculiar feature to investigation besides its relative proportion to the whole stroke, inasmuch as it is symbolized by a constant load acting against the piston, COMPRESSED AIR. 13 along a certain distance, which corresponds to the elementary definition of work as previously given. We are thus left to concentrate our attention upon the period of compression. The variations of volume and of pressure of air, which occur gradually during the process of compression, do not follow the same law in all cases; that is to say, this variation is different, whether the compression takes place at a constant temperature (isothermal compression) without any loss or gain of heat, or by allowing the increasing heat developed during the com- pression to remain integrally in the air; in other words, if the compression is done at variable temperature (adiabatic com- pression). There is no intention to develop here the laws governing the pressure and volume of air in those two sorts of compression . This would necessarily involve the use of mathematical formulae, which we wish to avoid. Suffice it to say that, if the temperature of the air remained constant throughout the compression, the volume which it occupies at any moment would vary in- versely as the pressure. Taking, for instance, 1 cubic foot of free air at 60 degrees Fahr. , its pressure is, therefore, 1 atmosphere, or 14.7 lbs. per square inch above a vacuum, or also zero gauge pressure. Suppose that this air is confined under the piston of a closed cylinder, and that, driving this piston forward, we reduce the volume occupied by the air to }i cubic foot only, at the same time maintaining always its temperature at 60 degrees Fahr. Then the pressure of this air would be 29.4 lbs. per square inch above a vacuum (or 14.7 lbs. gauge), that is, twice what it was before. If the volume was reduced to )/$ of a cubic foot, its pressure would become 3x14.7, or 44.1 lbs. per square inch above a vacuum or 29.4 lbs. gauge, always upon the condition that the temperature remains, throughout this process, at 60 degrees Fahr. In other words, if the volume of air becomes 4, 5, 6, 10, 20 times smaller, its pressure becomes 4, 5, 6, 10, 20 times greater, always taking the pressure of the atmosphere (or the gauge pressure plus 14 7 lbs. per square inch) as unit, and not the gauge pres- sure, which would lead to absurd conclusions. These pressures counted above a vacuum are called absolute pressures; the pressures indicated by the pressure gauge of a boiler are termed effective or gauge pressures. The absolute pres- sure is obtained by adding 14.7 lbs. to the corresponding gauge pressure; and conversely, the gauge pressure is obtained by subtracting 14.7 lbs. from the corresponding absolute pressure. Let us take a cylinder open at one end (Fig. 2) and a piston moving in it. Suppose that the piston is at 48 inches from the cylinder head, that this space has been filled with free air through the inlet valve, and that the pipe leading from the discharge valve casing communicates with a receiver wherein the pressure is 73.5 lbs. gauge per square inch. COMPRESSED AIR. 1 5 We will assume, also, that the compression is isothermal; i. e., that the temperature in the interior of the cylinder re- mains the same as in the open air. If we move the piston 12 inches, the volume occupied by the air is 36 inches, or % of its former length, 4^ inches. The pressure must, therefore, be the reverse, or % of the atmos- pheric pressure; i. e., 19.6 lbs. absolute, or 4.9 lbs. gauge. Similarly, when the piston has successively covered 24, 32, 36, 38.4 46 inches of its stroke, the absolute pressures are respectively: 29.4, 44.1, 58.8, 73.5, 82.2 lbs., and the gauge pressures 14.7, 29.4, 44.1, 58.8, 73 5 lbs., per square inch, which are marked on the sketch. If the piston moves further on, as the pressure in the cylin- der is the same as in the receiver, the discharge valve opens; there is no more compression, and the remaining 8 inches of stroke are completed by the piston against a constant gauge pressure of 73.5 lbs. per square inch. Let us now draw a line, A D, which, at any scale, repre- sents 48 inches, and mark on this line some points at 12, 24, 32, 36, 38.4, and 40 inches from its left end; then draw at those points some lines 12-2, 24-3, 32-4, 36-5, 38 4-6, 40-7, perpendic- ular to A D. Now, on these lines, let us carry, at any other scale, the gauge pressure at the corresponding point of the stroke; this will give us a succession of points 2-3-4-5-6-7, and, if we join them by a continuous line, a curve A B, that represents the variations of air pressure during the compression. This curve starts from the point A, where the gauge pres- sure is zero. If we took any number of intermediate points between 40 and 48 inches of the stroke, the pressure would always be 73.5 lbs. gauge, and consequently the curve of compression A B is followed by a line B C, parallel to A D, and representing the delivery under constant pressure: so the diagram A B CD gives us a graphic representation of the isothermal compression and delivery of air during one stroke of the piston, and its area represents the work performed during that stroke, for each square inch of piston area. The law of isothermal variation of the pressures and vol- umes applies to decreasing pressures as well as to increasing ones; thus, if we cause one cubic foot of air at 73.5 lbs. gauge (88.2 absolute) to occupv 6 cubic feet, its pressure will become 14.7 lbs. absolute per square inch or o gauge pressure. In other words, the curve of isothermal compression is also the curve of isothermal expansion, and the diagram A B C D' represents either the work of compression and delivery of a volume of free air, to 73.5 lbs. gauge, or the expansive work of the same body of air at 73.5 lbs, gauge pressure, and expanded from that pressure to the atmosphere, when it resumes its prim- itive volume. The practical meaning of this is, that if we compress a 1 6 COMPRESSED AIR. certain mass of air in a closed cylinder, by pushing the piston forward by a certain number of inches, and then, if we let the piston free, the air will expand and push it. back; and should there be no friction between the cylinder and the piston, this latter would return exactly to its starting-point, performing during its reverse stroke exactly as much work as has been required to push it forward. Quite a similar course of reasoning leads us to conclude that if we compress air isothermall} 7 in a cylinder, and if its discharge valve chamber (this valve being loaded to receive pressure) communicates through a pipe of any length, with another cylinder exactly alike, located at some distance from the com- pressing cylinder, we can obtain isothermally (neglecting resistances) from the second cylinder the same amount of work that has been developed in the distant first cylinder. The first cylinder is the compressor, the second is the motor, connected by the air main to the compressor; the whole is a perfect compressed air transmission, wherein a given amount of work is integrally conveyed to any distance from its point of production. But were we to establish such a system we would find that in practise the work recovered from the motor would not be equal to the work developed in the compressor. To reduce this difference (which is the keynote of economy in this system of power transmission) to be as small as possible, constitutes, in a nutshell, the whole scope of pneu- matic engineering; and as the first condition to fight a difficulty is to locate it, and to size it up, these remarks will be concluded by a few explanations showing what are the causes of discrepancy between the work expended in the compressor, and the work recovered from the motor, and how they can be partly eliminated; their total disappearance^ or rather counter- acting, being a purely practical matter, which has no absolute limitations. The fact of compressing air in a cylinder is always accom- panied by a production of heat. What causes this heat lo develop in the case of air is a question the precise answer to which would carry us too far into theory. It may be said however, that modern science considers air as formed of minute particles in a constant state of vibration, and that com- pressing a volume of air which contains a certain number of these particles causes them to increase the rapidity of their vibratory motions, hence friction, impact, and heat. Direct experiment, made from the freezing to the boiling point of water, has shown that the pressure of air remaining the same, its volume at 32 degrees Fahr. increases by X?3 f° r each increase of 1 degree Fahr. in the temperature of this air. From this we see that air at the temperature of boiling water has increased in volume by l8 % 93 =o.366, or 36.6 per cent, whilst this same air, at 493 degrees below -the freezing point of water, or 461 degrees below zero Fahr. has shrunken: by 49 X9 3 of its volume, or by that volume itself. This is how the temperature of absolute zero was ascertained. COMPRESSED AIR. 17 Compression will generate heat, and only should it be pos- sible to eliminate it as soon as produced, would isothermal compression be obtainable. It might probably be done by a very slow and gradual compression, combined with copious means of cooling the air in the compressing cylinder. But these conditions correspond to a practical impossibility, and there is in consequence a considerable amount of heat dis- engaged during the compression. The following table gives the temperatures Fahr. of dry air at the end of its compression, to different gauge pressures iu adiabatic compression; i. e., supposing that no portion of the heat developing is lost in the course of compression. \bsolute Pressure. Gauge Pressure. Fahr. temperature at (Lbs. per sq. in.) (I,bs. per sq. in.) end of compression. 14.7 O 6o° 16.17 1.47 74-6° 18.37 3-67 94-8° 22.05 7-35 124.9 25-8r 11. n 151-6° 29.4 14.7 175.8 36.7 22 218.3 44-1 29.4 255-1° 5i-4 36.7 287.8 58.8 44-1 3'7 4° 73-5 58.8 369.4° 88.2 73-5 414-5° 102.9 88.2 454-5° 117.6 102.9 490. 6° 132.3 117. 6 523-7° 147 132.3 554° 220.5 205.8 68i° 294 279.3 781 367.5 352.8 864 We see that as the pressure increases so does the tem- perature, and that when, for instance, the pressure has reached 73.5 lbs. gauge per square inch, the temperature is 414.5 degrees Fahr., instead of 60 degrees, as was the case in isothermal compression. The result is, that if we take the same cylinder which was used in that case, i. e., if we act on the same weight of free air,, this air, when at 73.5 lbs. gauge, will be 354.5 degrees Fahr. warmer in adiabatic compression than it would in isothermal compression. Its volume must therefore be necessarily greater in the former case, since the pressure is supposed to be the same. The practical meaning of it is that in adiabatic work the period of compression is shorter and the period of delivery is longer than in isothermal work; as the work at full pressure is naturally greater than at any time during compression, when the pressure is smaller, the adiabatic work is greater than the isothermal work, to raise the same weight of air to the same pressure. For 73.5 lbs. gauge, and atmosphere at 60 degrees Fahr., l8 COMPRESSED AIR. the adiabatic work is 1.31 times the isothermal work. But if the work done by the motor is correspondingly greater, what harm does the heat do ? There would be none but for the fact that the motor is always at some distance from the compressor (otherwise there would be no reason to transmit power), and the air parting easily with its heat, its passage through the receiver and the main will reduce the air to the temperature of the atmosphere; i. e., after compressing a volume of hot air EC D (7 (Fig. 3), we shall introduce in the motor a volume B C D E of cold air of the same weight and pressure. Now, this volume will expand in the motor either isother- mally or adiabatically. As we saw that the work of compression disengages heat, similarly, but conversely, does the work of expansion absorb heat from the surrounding bodies, and as the isothermal com- pression would require a slow process with copious cooling, so would the isothermal expansion require a slow process with copious heating. Unless this is done, the expansion will be rather adiabatic. Rather, because if isothermal conditions never strictly obtain in practise, the same is true with adiabatic work. If we expand adiabatically the volume of air B C D E, at 60 degrees Fahr. and 73.5 gauge, to atmospheric pressure, the work of expansion represented by the diagram B C D K, will only be 0.595 of the work of adiabatic compression. A compressed air transmission seems, therefore, to be an inferior system, the more so as the above figures do not take into account all the losses incurred, but only the thermic losses; i.e., such as are due to loss of heat. Several means are resorted to in order to reduce this loss. Suppose that the volume of cold air, B C D E, when it arrives at the motor, be reheated at constant pressure (73.5 lbs. g. ) until it becomes equal to F C D G; then we shall be able to develop in the motor by the expansion of this volume of hot air the same work that was used to compress it adiabatically. So if there was no other loss, the motor would utilize 100 per cent of the work of compression. Indeed, should the air arriv- ing at the motor be reheated to a higher temperature than that reached in the compressor, the work recovered would be greater than the work expended; and there is no absurdity in this statement, for such a result is easily attained at the cost of a certain quantity of fuel, which must be taken into account and deducted in figuring up the actual efficiency of the motor. Reheating the air upon its arrival at the motor is, indeed, the bise of the superiority of compressed air as a medium of power transmission. No corresponding feature exists with electricity to the pos- sibility of increasing at any time the intrinsic energy of the motive agency in an easy and inexpensive manner. There are, however — at least at present — some practical limitations to this reheating ; compressed air cannot conve- COMPRESSKD AIR. 19 20 COMPRESSED AIR. niently be admitted into a cylinder at a temperature much above 350 degrees Fahr. ; while we have seen that in adiabatic com- pression, the temperature corresponding to 73.5 lbs. gauge is 414.5 degrees, and this illustration points out one reason why low pressure air is more economical, for power purposes, and also the use of compound compression where the rise of adiabatic temperature is small in comparison to single stage machines. No lubricants of the ordinary description will be fully active beyond this temperature: special oils, however, are made which are not decomposed belore 500 to 600 Fahr. But it is evident that, could the compressor and motor cylinders, pis- tons, and packings be made of a substance that would with- stand great heat without injury or the usual lubricants, the reheating could be carried far enough to compensate for all other losses, a feature exclusively characteristic of air; and there is no apparent reason why such a substance could not be discovered, and it will reward undoubtedly its discoverer in a day not far distant. Without entering into many particulars, it may be stated that when the compression from atmospheric to receiver pres- sure is effected in one cylinder, the air is cooled either by sur- rounding the walls of the cylinder with a jacket, and providing in the heads some hollow chambers, through which a continu- ous stream of cold water is rapidly circulated: this is called " dry cooling," because no water comes in contact with the air, and represents, without exception, the best American practise. Or else, a spray of finely divided cold water is injected in the body of air under compression. Here, the contact is direct between air and water, so this system is more effective than the dry cooling; and if the jacket arrangement is used in connection with the spray, a marked improvement occurs in the cooling of air. This wet cooling has, however, some practical disadvantages, which led to discarding it in this country, while in Europe i, is still found in recent high-class compressing plants. Another effective means of cooling consists in compounding the compressor; i. e.,in effecting the total compression through a series of successive cylinders, in each one of which only a partial compression is effected, generating little heat, which is more easily dealt with; besides, the air in passing from a cylin- der to the next one in the series is discharged through a cooler, where it resumes the outside temperature. For high pressures, compounding is a necessity, and the efficiency of the compression is thereby increased. The ideal compression is, of course, the isothermal; and its efficiency being 1, we have the following relative efficiencies for other systems, when air is compressed to 6 atm. effective, namely, Adiabatic, without cooling 0.744 Adiabatic, with jackets .80 Adiabatic with spray 0.85 COMPRESSED AIR. 21 Adiabatic compound (2-stage), jacketed, with intercooler but no spray 0.863 3-Stage compound, with intercoolers and with • spray 0.955 The effect of cooling is first to improve the efficiency of the compression; i. e., to use less work in producing it; and then, at the same time, the amount of heating is proportionally reduced. A mere mention will be made of the loss incurred by the air pressure on its passage through the main connecting the compressor and the motor. Tables will be found in this book giving the loss of pressure through mains of different lengths and sizes, and for different velocities of circulation of air. In a general way, and especially in a long transmission, there is a conflict between the first cost of the plant and its efficiency, which both increase with the size of the main. In a properly built line, the loss can be made very small, and its value will generally be assumed to suit local conve- nience, according to whether the first outlay or the cost of power is to have more weight in arriving at a decision. It is hoped that the preceding remarks will enable any in- telligent reader to form a correct idea of the elements to be taken into consideration in installing a compressed air plant or compressed air transmission, and briefly they may be enu- merated: 1. An economical prime motor. 2. A compressor, which, while having a high mechanical efficiency, has also means for reducing the heat of compression to a minimum during and between the periods of compression. 3. A pipe line involving the least loss by friction consist- ent with the finances at command. 4. Motors, which, beside possessing a high mechanical efficiency, have means to expand the air to the atmospheric pressure, which must be done by reheating to as great a tem- perature as possible, both before and during the expansion of the air in the cylinders or upon the motor wheel. TABLES FOR THE LOSS OF PRESSURE OF AIR IN PIPES. In calculating tables for the loss of pressure in pipes, it has been found necessary to take a wide departure from the form of the tables usually given in catalogues on Compressed Air, and whose simplicity unfortunately does not agree with more recent experimental results touching upon the subject. The formulce from which such tables are generally estab- lished are the outcome of experiments made at the Mount Cenis Tunnel, and of Stockalper's more recent investigations at the St. Gothard Tunnel. 22 COMPRESSED AIR. Similar formulae have been used, with some modifications of detail, bj 7 Professor Riedler, who conducted extensive tests upon the. compressed air system in Paris, and they are based on the assumption that the loss of pressure varies directly as the length of the pipe, and inversely as its diameter. Professor Unwin took up the subject, availing himself of the results formerly obtained, and his investigation of the laws governing the motion of air in long pipes does not support the above-quoted conclusions. Taking, for instance, three pipes, each 5 inches in diameter, wherein air enters at a pressure of 70 lbs. gauge, and at a velocity of 20 feet per second, if one of these pipes be one mile long, the second 2 miles, and the third 5 miles long, the loss of pressure according to Unwin 's formula is: 4.6 lbs. for the i-mile pipe, 9.4 lbs. for the 2-mile pipe, 26.3 lbs. for the 5-mile pipe. In other words, the lengths being as: 1 - 2 - 5, the drop of pressure varies as: 1 - 2.043 - 5-7 2 ! and while the discrepancy is unimportant for short lengths, it becomes 14.4 per cent at 5 miles, and would be still greater for longer pipes. As the logical tendency is toward increasing the practical length of power transmissions, a saving of a few pounds of loss is important; consequently, in working out a compressed air transmission, more precise data are needed. To meet this re- quirement, the following tables were calculated from Un win's formula. From the preceding example we notice that the loss of pressure increases more rapidly than the ratio of the lengths; besides, this loss does not vary inversely as the diameter of the pipe. Taking a 4-inch pipe, 2000 feet long, into which air at 60 lbs. gauge enters with a velocity of 15 feet per second, the loss at the lower end will be 1.19s lbs.; according to the old rule, the loss in an 8-inch pipe of same length, and at the same pressure and velocity of air, would be one-half this amount, or °>5975 ^s.; yet Unwin's rule makes it 0.52 lbs. In the same way the loss in a 12-inch pipe should be 0.398 lbs., while its actual value is o.j lbs. Here the loss of pres- sure decreases more rapidly than the diameter increases. And if we accept the theory that recent rules, when ema- nating from a reliable source, are the best, we must conclude that no satisfactory approximation to exact results can be ob- tained with the proportional formulae. In the annexed tables, the air pressure at the entrance to the main has been assumed to be 70, 80, 90, and 100 lbs. gauge, which figures cover the working pressures at which air will generally be admitted to the motors. The use of the tables involves a few elementary operations, which we have clearly defined in several numerical examples, COMPRESSED AIR. 23 selected to suggest a ready method of solving any ordinary problems. Some little calculation must of necessity be done, inasmuch as to construct a series of tables, which would take into consid- eration every element which influences all cases of transmission, would necessitate too much elaboration, and would not be de- sirable in a treatise of this character. EXAMPLE 1. 500 cubic feet of free air is compressed per minute to 80 lbs. gauge, and conveyed through a 6% -inch pipe, 2 miles long. What will be the air pressure at the lower end of the pipe? Referring to Table Fig. 5, which deals with air compressed to 80 lbs. gauge, and starting down column 3 (size of pipe in inches) we stop at 6-% ins. On the left side (Col. I) we find for the ratio of absolute air pressures at lower and upper ends of main : -j fi — 0.00000003709 v t 3 1 (z/, is the velocity of air at entrance to main, in feet per second, and / is the length of pipe in feet.) Following now the horizontal line to the right until it meets the vertical column headed 500, we find 36.5 which is the value of v t 2 . So z/, 2 1=36.5x5280X2=385,440 and the ratio of air pressures (Col. I) becomes: / 1 — 0.00000003709X385,440=0.992 The pressure at entrance to main is 80 lbs. gauge or 94.7 lbs. absolute; the pressure at the lower end will be: 94.7X0.992=93.9 lbs. absolute 14.7 Or 79.2 lbs. gauge. The loss is: 80 — 79.2=0.8 lbs. EXAMPLE 2. How many cubic feet of free air per minute, compressed to 90 lbs. gauge, can be conveyed in a 9-^6 inch pipe^ 5 miles long, the loss of pressure to be 3 lbs.? The absolute pressure at entrance to main is: 104.7 l° s - The absolute pressure at lower end is: 101.7 " Their ratio is: — = 0.971 104.7 Referring to Table Fig. 6 (90 lbs. gauge) and following Col. 3 down to 9-^$ inch, we find on the left of this figure (Col. 1) 24 COMPRESSKD AIR. 1 1 , a \ M o < 3 vl 3 u 1 » 1 ^ s s> fi 1 <9 <5 «1 * ■ w ^ 1 r: r "1 v> r £ «a s °o ^ ^ | 1 1 w ^° £ S 3 * * - 1 ? t? J Vl N * N Jr ? N °~ < j l g £ Va •y rt 03 i K £ * 1 I ^ j i ! 1 5 l\ 00 ■J | 3 T ! - ^ ft > V ft i > 1 > a- 1 > 1 > :> > > 00 > 1 > > vo > > a (0 > 1 i i Pi i COMPRESSED AIR. 25 1 1 a \ S- ■ -si 11 O i «. : < r °o0 l£ 1 o .-J _^ o 4 1 i « g Ml> 1 s 1 1 II 1 "? ' 3 T | S JS 4" £ £>. 4 r * ! ^ e 1 < - . j; •* % 1 | 1 R ^ I r | ^ Ss « + -r | 2 |s o << J 8 s- i I I 2 K i? ? 1 £ : £ | 5 I r * ? - S J *i T 2 ■ 3 r S £ • JN s T N. V ^ I & ^ x5 S Ut 5 \9 !S 2 * I o- IS. > > 1 ^1 p % c° w »- J- 8" 2 ^T !o c< £ (n >r T 5- j ^ a In t ' ^ i « 4 s 1 £ s - 2 N» 5 ^ 1 J * rt 4 ' •s S- ? t v- T vj s , ! T fc" v9 iU : j ■ v» <4 l l' f - s » 4 of -, •T <0 vS N OO *>l V 1 > oo to > N > o o I > a- 1 > > 1 > o o 1 > «0 1 > > d 1 > 1 \ i 1 26 COM PRESSED AIR. 1 II II * I, J 1 1 'I o O ^-> O" O U 1 S lli j i 1 ft. J « T - T ^ ( s ^ 3 1 1, 5"- f § 1 1 « ¥p 1? * rt s A z '2 rt 2 T ■i 1 f? 8 - 5" 3 s *k S 2 . (* * a i & 3 it. J" a) - d > < * > 1 .i 00 £s 1 f\ i ^ 5 1 5 s j 4? <» 5» s ts ^ 5 i. 1 1 5 5 3 " "! r f< ,' <5 1 1 • 2 5 " rt 5.> £ 4- i;;s I || rs r 5 sfl * C" - 5 - i i CO f js 1 |«* - 4 - ^> N. -JT 4^o > > V i > IV. > > > d > rs > 1 > SO Mi o 1 > SO SB 3^ > s» > 1 6 i j COMPRESSED AIR. 27 a. J 1 S s 3 e. 3 u £ J 5- £ £ lo In v> £. 4 2 ° 1 3 •* 2 i IK r £ .Ml* "N. |S. A I 2 s & « £ & >• (0 '\ J 5 « J s* £ J -4- j( 1 .2 » i." 1 a 3 r- > d > < 1 03 5 I 1 « 5 1 M IS. d 5" j \ I ■N. s jg ts *;5 'S A ISs. - • u n J ^v 1 H § " £ ? • £ ^ lo 3 .»- lo > ex fS, > > - 1 > rs. > > > <0 > > > 1 1 28 COMPRESSED AIR. that the ratio of absolute pressures at lower and upper eud of main is: 1 f i — 0.00000002075 z\ 2 / and as we know that this ratio is equal to 0.971, we may write: 0.971=1/ I — 0.C00C0002C 75 z/, Or, squaring both members of this equation: 0.9428=1 — 0.00000002075 v x 2 X528oX5 Or: 0.0005478 v x *=i — 0.9428 hence: z;, '=104.4 which we must find in the horizontal column starting from 9-^ 7/ ; we see that this number is comprised between 84 (2000 cu. ft.) and 131. 3 (2500 cu. ft.). The required number is intermediate between 2000 and 2500 cu. ft.; it can, with sufficient accuracy, be obtained by interpo- lation: 131. 3 — 84=47.3. Corresponding to a difference of 500 cu. ft. of free air (from 2500 to 2000). 104.4 — 84=20.4, which, by a simple rule of three, corresponds to: §QOY.~—2\$, and the required number of cubic feet of free air per minute is: 2215. EXAMPLE 3. We desire to convey 1000 cu. ft. of free air per minute, com- pressed to 70 lbs. gauge, through a pipe 3 miles long, the loss in pressure not to exceed 5 lbs. What must be the diameter of the pipe 1 This diameter could be determined directly, but through calculations more intricate than by the tables, which can be used in the following manner: The pressure at entrance to main is 84.7 lbs. absolute. The permissible loss is 5. The pressure at the lower end oi main is: 79.7 lbs. absolute, and the percentage of loss is: §3=°-94. Referring to Table Fig. 4 (70 lbs. gauge) the right value of vf 1 is somewhere in the vertical column headed 1000. The length is 15840 feet=/. We will try some values of z', 3 and apply them to the cor- responding ratio of terminal pressures, until the result is exactly or approximately 0.94. If the result is not exactly 0.94 we will then take the nearest larger commercial size of pipe, thus giving less than 5 lbs. loss through the main. To facilitate these approximations we may remark that, COMPRESSED AIR. 29 using the formula of Col. I, we will have an expression of this form: -V 1 — o. 0000000 v 0.94= in which the stars represent some numerical value to be dis- covered; or, squaring both members of this equation: 0.0000000 * * * "* z\ 2 /=i — 0.94 2 =0.1164 Let us try v t 2 =4^g, corresponding to a 5-in. pipe, we have o. 00000004972 X449 X 1 5840 =0.3536 which result is much too large. We see that we have evidently to take a smaller value of z', a since / remains constant, while the factor corresponding to 4972 diminishes with z\ 2 . Trying v x 2 =ioo, which corresponds to a 7%-mch pipe, we 0.0000000299X100X15840=0.0474 which is below the value o. 1164 which we desire. Taking i\ 2= i83, which corresponds to a 6X-i"ch pipe, we 0.00000003709X183X15840=0.1075. This is the nearest value smaller than 0.1164 and will give less than 5 lbs. less; and thus we conclude that the required diameter of pipe is 6X ins. A short use of the tables will render them quite convenient to use: The above three examples cover the principal question liable to arise in ordinary practise, and the few calculations involved are more than balanced by the greater correctness of the results derived from Unwin's formulae. We can use the tables to find the loss of pressure incurred in the passage of air through a pipe of a given diameter and length, and with a given velocity of ingress. But it is interest- ing to know at the same time the corresponding loss of power. With this object in view, a Table (Fig. 9) and curves (Fig. 8) are here given, showing the ratio of available power at full expansion and without reheating at the lower end of the main to the available power at full expansion and without reheating at its entrance. These curves show that the comparative loss of power is always smaller than the comparative loss of pressure, and they will be found useful in estimating the total loss incurred in a given transmission. Each curve corresponds to a certain pressure at the entrance to the main, these pressures being, as above, 70, 80, 90, and 100 lbs. gauge. This addition to the study of the frictional losses is intended to dispel the confusion frequently made between the loss of pressure and the loss of power, there being a common tendency to consider those two terms as equivalent. COMPRESSED AIR. COMPRKSSED AIR. 31 i 3^ \ ? i"?'* 1 1 * tf ^r cr \0 r<) to CO 4-1 1 * 1 1 CO cr »0 cr cr CO CO cO 00 \ cr \ st vo ") ! : ! p -: ° 3 J 1 * 1 8 = 2 3 6 2. < i 5! ■ 1 1 I b > 0- <0 K O <~ 1 C I. * I N IV *) N 0- fO ^ * * - j Ift o) -*- V v£ « J- •> rO o tr* X. ^0 « C? Ll. *> rt # S cV i- Q 3 © o S © ' "" O ^ o '3 > J- J. 2 4 J Sw £ «j> 5 •' _? CL sE 5 -b * V Q» q) s C* C tf) £ V «-*- i2. o 1 £ « .£ ~i COMPRESSED AIR. 35 THE INFLUENCE OF THE DIFFERENCE OF EEVEE ON THE USE OF COMPRESSED AIR. The calculations concerning the applications of compressed air are generally based upon the standard values of the at- mospheric pressure at the sea level; viz., 14.7 lbs. per square inch. The fact that a large number of mines are located at a considerable altitude makes it necessary to investigate the influence of this condition upon the use of compressed air, and it will be shown herein that the differences of level are not to be overlooked in designing a system for power transmis- sion. The weight of one cubic foot of air, at the surface of the earth, and at 32 degrees Fahr., and when the barometer stands at 30 inches, is 0.0807 lbs. The position of the mercury in a barometer is due to the weight of a column of air. whose height would be the thickness of the atmospheric layer that surrounds the earth, and as one cubic inch of mercury weighs 0.491 lbs., the weight of a column of mercury 1 inch square and 30 inches high is 30X0.491=14.73 lbs. Hence the con- clusion that a column of air 1 inch square and of the height of the atmosphere weighs 14.7 lbs., and will balance the weight of a column of mercury 1 inch square and 30 inches high. The immediate consequence of this is that as we rise above the level of the sea at a given place, the atmospheric pressure per square inch must decrease, since the height of the column of atmosphere pressing on the mercury of the barometer diminishes, and we can readily calculate that if the whole at- mospheric layer were of equal density, that is, if one cubic foot of air had the same weight at any altitude, the thickness of our atmosphere would be 26,208 feet, or 4 97 miles. Such, however, is not the case. The weight of one cubic foot of air varies with its pressure and with its temperature, which both change with the altitude. It is commonly assumed, that at the same latitude, the temperature drops by 1 degree Fahr. for every 340 feet of height above the sea level; but this could not be taken as any- thing like a general rule, since the temperature is affected by many local and variable conditions. It suffices, however, to show that the density of air changes with the altitude, but as the laws of this variation are imperfectly known, and only for moderate altitudes, the exact thickness of the atmospheric layer that surrounds our planet is a matter of speculation. It is generally conceded, however, to be about 45 miles. The variations of atmospheric pressure with the altitude have been, in the annexed table, calculated from the sea level to io,oco feet above it, and for equal steps of 500 feet, on the assumption of a constant temperature of 60 degrees Fahr. pre- vailing throughout the change of altitude. This supposition, however, as we have mentioned before, is not correct, but the exact influence of the temperature can easily be computed for any particular instance. 36 COMPRESSED AIR. An inspection of the table of atmospheric pressures leads to an immediate practical conclusion. Iyet us take, for instance, a machine designed to compress at the sea level 500 cubic feet of free air per minute to 80 lbs. gauge, that is, 80 lbs. above the atmospheric pressure. The volume of cold compressed air de- livered per minute is 500X^=77.6 cu. ft. Suppose now that the same compressor be used at 5000 feet altitude and run at the same number of revolutions; the piston will sweep through 500 cubic feet as before, but the atmos- pheric pressure being only 12.14 lbs. per square inch, the volume of cold air at 80 lbs. gauge delivered per minute will be 500X^=65.85 cu. ft. That is to say, the delivery of air at 80 lbs. gauge and at 5000 feet altitude will be 85 per cent of the delivery at 80 lbs. gauge and at the sea level, from the same sized compressor running at the same number of revolutions. These volumetric variations, reckoned upon the volume at the sea level taken as a unit, will be found recorded in four columns corresponding respectively to 70, 8o, 90, and 100 lbs. gauge and annexed to the pressure column. It will be noticed that the volumetric efficiency, that is the ratio of the delivery at any given altitude to the delivery at the same pressure and at the sea level, decreases as the receiver pressure increases. We know that in adiabatic compression (which we may take as a standard of comparison) the compression to 80 lbs. gauge and delivery of 500 cu. ft. of free air per minute absorbs 79.4 I. H. P. It may easily be calculated that for the same outside temperature (60 degrees Fahr.) and the same gauge pressure (80 lbs.) the compression and delivery at 5000 feet altitude of the same amount of atmospheric air will absorb 73.7L H. P. The ratio of these powers is ^=.928. That is to say, we lose in capacity 15 per cent and we gain in power 7.2 per cent, which amounts to saying that the produc- tion at the same volume of air at the same effective pressure will require: 1 I. H. P. at the sea level, 1.093 " at 5000 feet, 1. 1 90 " at 10,000 feet altitude. It costs more, therefore, to obtain the same useful work from a given compressor at high altitudes than at the sea level. Four columns of I. H. P., referring to the compression of 100 cubic feet of free air per minute to 70, 80, 90, and 100 lbs. respectively, are recorded alongside of the volumetric results. An inspection of the table shows that if we compare the work absorbed by 1 cu. ft. of air delivered at a given pressure, at 10,000 feet altitude for instance, and at the sea level, the ratio will be practically the same within the whole range of pres- sures considered. COMPRESSED AIR. 37 a o to v» « <5~ eci IV 00 tr- io -7 CO to 00 s* d oo t\ «0 rs N S3 d rs 1 a .1 si *» -J sfl rv. s» vft d ^ d o- d i < ll !i > • f> N o- o- 00 OB v» oi « ir er FN rv •0 (V vS d K -2 t n Q_ C. 3t o 05 a d K <0 •*■ in ro T * * 5 * 3 d »v a- «»■ J -t *> > • VT N e. rv. 4 -J d I v9 £ «9 d a- d cr a- <<7 rv W * d «0 se rv. rv ; 4 o © > 1 "* | Mil K ■i T> ; O o o in o o o O O o "xT vT K «o £- <±: • "S 3 cD *i cV «■> *> c w {1 J. 00 v, vo a~ ^ VO •^ ^LLi f*i - J -T 00 <*> <0 O i[ 5 s 2 O j t*5 •I s | o \9 K o oo si- 3- N \9 4- 5* -T o 1 i 1 S 2 * «r> X rf\ o 2 « o ^ v> 00 I 1 1 I "" 2 ro » 1 * 1 i 1 £ >> a \ o .J O "J i. | 3 L H " 1 (0 N •J- H M S .S >■" ^ - 5 »- J: s -•<«■- 2 Ml s MJ « <0 vo * i ill 1 *' 5 4 c « s N N ^0 | i 1 * * 1 vO * «) (0 fO rt rT) J * S S° i in? 1 1 1 1 3 ] ^ -UJ 2 -5 O 1 - J 3 " -? Oj £ GL X <0 m 00 5- ffl ■- |: 1 S_ t 3. o ] 1 -S-Sf o -J 11 5 -Si s -a o \ co O 6 <0 00 cr 11 2$ J "3-- •; ,?-> r O s ^ x ! > S. i -s K. o o 00 3 1 2 2. 51 i i i-£ * to in •o C 5? "3 VO o- UJ 3 -T 5 -O^ -l« d V 1 ^ - \o = rs 1 Tl N I tf In s o - tf 1 J COMPRESSED AIR. 43 * O N, » © «Q rv <£> *> *> -PO 7 ji -> fc vS > •a- N ^ VO K S 1 £ m *° q- N IV cr- ^ •» 1 ~ Sr «6 «o «9 r* cr- ■3- > S >o -i f° 's cV oo sa H j t v v> »\ N V9 y> ^ N \s •3- cr J rf N Is. cr £.*) nt *s \J> N8 Oo < p- s" j '* J ~" \^ o £15 V3 \0 vs cr o s 00 00 ^^ L. 1-- 35 •T Oo Vfl ■Sis-S g o J sr N «o 00 cr- - w <^«o . -14- ■J S e* • -T *o -3" *: ^ « 21 *? * sr rf) rt) cO c*) ^ /> v- gr 3 iA £ & vs o 2* i. Z x i "5 v~ iS O -- : ■- vo s i s J» y o 2: VO ■ -0 - «■ uf-l 1 ^0 t£ y-so •- £ '" X, CO CO <3- ,> * s 1 * i? *" NT sT £ 1 S_ _£\ . fO •o "O •* s: 'ill LU 3 jr> ■r -T *-\. SI <-»- * <^> "0 w 3 5 /!»{" W/'f \\ «f **» -.?•■* < .., ft»8'f " -Afri »$* **£, -A?/ i2i _E> a 3 2 °»>J W/ ■?wh a £ 'it «S 7 " /,t?i O °o »0J ?vr t«i v *»«7 - l ** 1 <3 o C_Ch! V V Hi th-f- J9€l U E 89t-l- Ofttl o 1 C ~" w « Zlrt- tctv I.I tr_~~~ z »fc 92oi - lS< J /til Uo', ctr- l---- •1 *<«; 9S» 1 '» ,H '"t D A. . M », N *> c^ 8 £ J « CD N t\ tf ] it c . en ^,oo -i -*n C £ ^ *5 *jj _c a: « - ^T * ^ lo to «o „, r«i ~> lO *o" 5 f-j^ « ' ? 3 o° y f i < -a ,5--" TJ ol (O 3 lo 1 v9 1 "1 1 1 x. L 1 ' 1 < v/5 "T3 < 3 -£ X ai U 3-1 — s: "v U "J "3 ! r t * \h ij "> u < COMPRESSED AIR. 51 ] c^ * rJ oe i £ I «» 1? o£ tf> m fO J "rf v H £ -^ i r^ S- x «3- tf 3 i I < I g r 5, a.- "I O j 54 COMPRESSKD AIR. - l v x ;■, i r \\A) * i ? - 5 11/ a . ]r -jf— n !«i <"> * *> i ' i - 1- M K i 1 & k I > ^ •> s3 $ < V r COMPRESSED AIR. 55 This table is constructed from the curve represented in Fig. 22. In the table the amount of air is given for each indicated horse power in the air cylinder and also for each I. H. P. in the direct-acting steam cylinder which drives the compressor. The table in Fig. 23 is practically the reverse of the pre- ceding curve and the table gives the I. H. P. to compress and deliver 100 cubic feet per minute of air, at 60 degrees Fahr. and 14.7 lbs. per square inch absolute pressure. This table is con- structed from the curve (Fig. 24) and gives the I. H. P. in the adiabatic compression, in single stage jacketed cylinder com- pression, in two-stage compound jacketed compression and also isothermal compression, and the horse powers under each of the different gauge pressures read both for the I. H. P. in the air cylinder and the I. H. P. in the direct-acting cylinder. Fig. 25 is the curve of mean effective pressures per square inch in adiabatic compression, for the various receiver pres- sures enumerated. This will be found useful in computing piston loads. Fig. 26 is a table of pressures per square inch, due to the weight of air at 60 degrees Fahr. in vertical pipes, and also the weight of one cubic foot of air in pounds avoirdupois. For example, if the gauge pressure at the surface of a mine is 70 lbs. per square inch, at the depth of one thousand feet the pressure will be 73 lbs. to the square inch. Where there are extreme variations in altitude in a transmission plant this weight of air has to be taken into consideration. 56 COMPRESSED AIR. < \ ^ .1 < < i , ^ i < i ^ i'\ i. i y *> 2 i£ o. 3 5 3 8 U 1 11 s i ^ * •« V n 3 »S a. * i " o 1 s 1 s r s- ' ^ > J a ^ <3 ?' 1 ' 5 « ? rV * 1 2" T- " 2 ** •^ 5 ^ v, 1 "§- dH 1 « ■3 | r r J ■i A ^ • < " ri - — 58 COMPRESSED AIR. '- * in> f 1 * 2 2 \ *" \ «, is - & 1 \ s | i i 3 .? CL J * ! < rs a- « -a < s 1 In > 1 • 5 : r H ? V... ! » -,,•»., »*.»l,5 „j ?3 <3 00 st V < 5 9 a) < c_ 5: vS rO < in -0 ci 1 a) er _d 1/) "** < <*> 3 Cl 0- 5 O * tf~ ii ^ 0) i^5 '3 J O 0) V d: > '-£- 1 £ * <5 O 1 1 £ 5 i 60 COMPRESSED AIR. AMOUNT OF FREE AIR REQUIRED TO RUN DIRECT-ACTING STEAM PUMPS. In preparing these tables the object has been to furnish information to the oft-repeated query, "How many cubic feet of free air, compressed to, say 60 lbs., is required to run a direct-acting pump that will raise 50 gals, per minute 200 feet high, or say 8 miners' inches 150 feet nigh, or at any other pressure of air ? " We have made three assumptions in these calculations, which are likely to cover all possible losses of efficiency in ordinary work. First — The work absorbed by the pump has been estimated by adding 20 per cent to the actual work in water raised, to make up for frictional and other resistances. Second — The actual capacity of the air cylinder, that is, the volume swept by the piston, has been increased by 15 per cent to take into account the clearance, leakage, etc. Third — The working pressure of air, when entering the air cylinder, has been taken at 10 lbs. per square inch lower than the receiver pressure, to compensate for frictional and other resistances. We have not assumed that the air was reheated before entering the cylinder, nor was any account taken of the differ- ence of level between the receiver and the pump, which in many cases would add several pounds per square inch to the working pressure, as noted in the Table (Fig. 26). The results given in these tables may therefore be referred direct to the intake capacity of the compressor and the estimate of the air consumption required is therefore very much simplified. If the necessary power to produce the quantities of com- pressed air indicated in these tables be compared to the cor- responding work in water raised, the efficiency, which is measured by the ratio of the latter to the former, will be as low as 25 per cent. A direct-acting pump does not use air expansively, and this is well known to be a simple but a waste- ful manner of transmitting power. Assuming the values in these tables to be one, the follow- ing table will show the percentages required for the different kinds of power-actuated pumps, both for cold air and air delivered at 300 degrees Fahr. at the pump motor. AIR. Cold. (60° F.) Reheated to 300 F. Direct Acting Single I .70 to .60 .60 •50 •33 .69 .48 to .41 .41 .329 .226 Direct Acting Compound ( Slide Valve Single .... Fly Wheel -j Slide Valve Compound / Corliss Compound COMPRESSED AIR. 61 li ^2 * >? * 0^ 0^ v« ? g. 1 *» <*? N. * ^ ^ 5 « $" 1 £ v§ Is K «0 hj $ y> 5 ^ ? - 1 * « 1 1 io to Ofl In £. •V «r- ^ ■8 J 1 >^ * £ OS as «o "J 5" 0~ -> l 0> T vS * v5 5- 4 ? 1 « 2 {S. 1 £ 3 ► f I it ? ^ a. « 5-> ^ 1 S 1 5 N 2 =3 * & M5 ^ 5 % *> l s a «o 8 >* W 2 3 «0 t* w -a a X D la to -? 5 ■0 ^ 5 1 - oS x * *" » S ■a- « * JS 1 '■■'> i •5* 3- 2 - - C^ m vC . VO 1 *» CT «i 5 1 I £ J» «- 5 <0 ii3 3- r 5 *. I g j II? •1" 8. &. J 1 0~ £ K * va *? § * i ft- 5! 5 3 I SI 113 1 C .* J! o "« -8 ■1 S 3 «0 ;u 0 •3" (a 1 £ 3 f 3 i\l * ■4 « = I <2 4 ^ 3 3 « «'l* ? 8 5? « ? 5s _1_ J 1*! £ 4 fr s s | *» fes X 1 3 (v, W* in 1* 3 1 Jj> 5 « v3 « 4 5 o 'i^ il* - « a '5 S T 8 5 ^ U u2 ■ | su 09 3 3 £ 55 <*> -5 2 3 1 Si (0 «-> * z £ U (- , ^r 0/ 00 .2 £ 5 a. j 5 ^ N 00 o 00 CO OQ <0 * o rV 1 o 3- VB o o rt 00 V 1 *~ "5 £ s o f«5 K f fY fO ^ s. <0 3- 3- cr 2 sa d cr- N «3 c ^ ^ > s: o rV 4" o SO -a- 4- C3~ CW 00 rO o cr 8 3 ^ ^ o t ' a 1 o -*- is. Jo o cr cr cr o u o o cr- ew £ rO K >>9 ? in rO 1 S „ - <* -IW -Icy -W -H -id -trf ->w -IW 1^ r> CO o W £ s£> oO r< c v 1 q 1 i RIX AIR COMPRESSORS. 85 1 li- O <6 03 CO ^0 1 V 0) +- "0 -u -IW Hd Jo Q <0 "5 -f Ul fO vs vs I ,2 •i 5 V if £ rf 1 Q »olT -IT $> k ^1 w ^r $ - •*- s- J! i c 1 u ^ cr Ol | 1 to 1 1? vrt a) if! "* <7 •5 - m '2 14 60 2 12 l2 l / 2 16 80 3 14 I4K 18 1IO 4 16 16^ 18 140 5 18 l8# 24 200 6 20 2oy 2 24 2 O j 7 22 22}i SO 3IO 8 24 24^ 30 400 RIX AIR COMPRESSORS. 87 88 RIX AIR COMPRESSORS. / 1 RIX AIR COMPRESSORS. 8 9 Fio. 34— Class A.— Rix Duplex Steam Actuated Compressor. 9 o R1X AIR COMPRESSORS. RIX AIR COMPRESSORS. 91 RIX SINGLE STEAM ACTUATED COMPRESSOR. Class B, Fig. 36. The following half-tone, Fig. 36, shows the general style of construction of Class B, Rix Single Steam Actuated Compressor, and Fig. 35 shows the side elevation of same. This machine differs only from the Duplex Compressor in the fact that it is one-half of that machine and has an outboard bearing. The following is a table of the various and proper dimensions. RIX SINGLE STEAM ACTUATED COMPRESSOR. CI.ASS B. For Revolutions per minute, Cubic Feet Free Air, and Rock Drill Capacity, see pages 84 and 85. No. Diameter. Steam Cylinder Di^meter Air Cylinder. Stroke. H P. Boiler Price. 9 IO II 12 13 14 15 16 IO 12 14 16 18 2 J 22 24 ioy 2 i6y 2 isy 2 2oy 2 22^ 24; 2 14 16 18 18 24 24 30 30 30 40 55 70 IOO I30 155 200 92 RIX AIR COMPRESSORS. a m RIX AIR COMPRESSORS. 93 RIX SINGLE STEAM ACTUATED COMPRESSOR, SELF-CON- TAINED TYPE. Class C, Fig. 38. This machine is one which is offered to the mining public as the least expensive andmost generallyuseful machine of the kind ever constructed. It will be noted from the half tone that this consists of an independent standard engine on a bed-plate con- nected to an. air-compressing cylinder, the whole being tied together for proper operation. The engine is self contained, there being no outboard box, the fly wheel pulley being over- hung, so that this machine can be placed anywhere and is ready for operation at once. A belt can be placed upon the fly wheel pulley and be used to operate a pump or any other machine that may be desired while the compressor is not in use, in which case it will only be necessary to remove one inlet valve on each end of the air cylinder and the compressor end of the machine becomes inactive. This machine is especially built for prospecting, temporary work and for experiments, where a permanent plant is too expensive. It will' be noted, from the construction, that the engine can be entirely removed and used independently should occasion demand, and the whole arrangement is one which gives a prospector an opportunity to easily dispose of his machine should his mining venture prove a poor one. The following is the list of sizes of the Class C Compressor. RIX SINGLE STEAM ACTUATED COMPRESSOR, SELF- CONTAINED. For Revolutions per minute, Cubic Feet Free Air, and Rock Drill Capacity, see pages 84 and 85. 17 18 19 23 24 25 26 27 Diameter Diameter Steam Cylinder Air Cylinder 13 14 16 18 Stroke. H. P. Boiler IO 15 IO 20 12 25 12 30 14 30 14 35 16 40 16 45 18 55 20 70 22 100 94 RIX AIR COMPRESSORS. ¥■■ ~»45M R1X AIR COMPRESSORS. 95 COM- RIX DUPLEX SHAFT- DRIVEN PRESSOR. Class D, Fig. 39. This half-tone represents one of the new style Shaft-Driven Rix Duplex Compressors, heavy duty style. This machine has Corliss frame, extra large wrist pins, and large cross head. The frame is swelled up on the front head so that the head may be removed without disconnecting the cylinder. The Compressor which was the subject for this half-tone was driven by a twelve-foot tangential water wheel, under a head of two hundred and seveuty-five feet. It may, however, be driven by belt. Fig. 40 is a side elevation of the same machine, showing belt pulley. Fig. 41 shows a sectional machine of the same class, but having a fiat bed, with water wheel attached upon the shaft. This Compressor, as all the sectional compressors herein- after mentioned, is made in sections not to exceed 325 lbs. in weight, so that they may be carried upon mules. The following table gives the sizes and principal dimen- sions for the Class D machines: RIX DUPLEX SHAFT-DRIVEN COMPRESSORS. CLASS D. For Revolutions per minute, Cubic Feet Free Air, and Rock Drill Capacity, see pages 84 and 85. No. Diameter Air Cylinder. Stroke. Price. 28 8 10K 13 12 14 16 29 30 31 32 33 34 35 36 16 y 2 i8 18^ 24 20^ 24 22^ 30 2A\4 "20 4/2 9 6 RXI AIR COMPRESSORS. RIX AIR COMPRESSORS. 9 8 RIX AIR COMPRESSORS. RIX AIR COMPRESSORS. 99 RIX DUPLEX TANDEM SECTIONAL SHAFT-DRIVEN COMPRESSORS. Class E, Fig. 42. These Compressors are entirely similar to the Class D Ma- chines as noted in Fig. 4r, with the exception that the bed is extended and an additional air cylinder placed tandem to the others. This makes a very convenient form of machine, and one which gives a large air capacity with little additional weight. These air cylinders are so connected up that any one of the four cylinders, or any combination of the four cylinders, may be run together. The utility of this machine will be recognized at once. Fig. 43 is a side elevation of this Class E machine. RIX DUPLEX TANDEM SECTIONAL SHAFT-DRIVEN COMPRESSORS. For Revolutions per minute, Cubic Feet Free Air, and Rock Drill Capacity, see pages 84 and 85. No. Diameter Air Cylinder. No. of Air Cylinders. Stroke. Price. 37 33 39 40 8 I4# 4 4 4 4 12 14 16 18 RIX AIR COMPRESSORS. y^iiJln* | J, be '" .-»J * ' RIX AIR COMPRESSORS. hB>- H&- #o 102 RIX AIR COMPRESSORS. RIX SINGLE SHAFT-DRIVEN COMPRESSOR. Ceass F, Fig. 44. This half-tone shows a flat bed type of compressor, but they are made also with Corliss frames, as shown in the Class D machines, Fig. 40, the smaller machines being made as per Fig. 44. This machine has an outboard bearing and may be driven either by belt, pulley, or by water wheel upon the shaft. Fig. 45 shows a side elevation of this Class F compressor. The following is a table of the sizes and general dimensions of this style of air compressor: RIX SINGLE SHAFT-DRIVEN COMPRESSOR. CEASS F. For Revolutions per minute, Cubic Feet Free Air, and Rock Drill capacity, see pages 84 and 85. 4i 42 43 44 45 46 47 48 49 Diameter Air Cylinder. E3 14>2 i6y 2 H 16 18 iS 24 24 KIX AIR COMPRESSORS. I0 3 io4 RIX AIR COMPRESSOR RIX AIR COMPRESSORS. I05 RIX COMBINED DUPLEX STEAM ACTUATED AND SHAFT- DRIVEN COMPRESSOR. (Xass G, Fig. 46-46^. This is a form of compressor which is especially adapted to the wants of the Pacific Coast, where there is abundance of water supply during one portion of the season and an insuffi- cient supply during the remainder. It becomes, therefore, necessary to run the compressor with water power during a portion of the year, and steam power during the balance. It will be noted from the half tone that the air cylinders are placed next to the water wheel, which water wheel has been built upon the fly wheel of the machine, the steam cylinders being tandem to the air cylinders, with a sleeve coupling between. When it is desired to run by water power it is only necessary to remove the sleeve coupling, and the machine becomes a water power compressor. The couplings may be replaced in an hour, at any time, and the machine again converted into a duplex steam machine, using the com- bined fly wheel and water wheel for a fly wheel. These compressors are made in the following sizes: RIX COMBINED DUPLEX STEAM ACTUATED AND SHAFT-DRIVEN COMPRESSOR. For Revolutions per minute, Cubic F'eet Free Air, and Rock Drill Capacity, see pages 84 and 85. No. Diameter Steam Cylinder Diameter Air Cylinder Stroke H. P. Boiler Price 50 51 52 53 54 55 56- 57 IO 12 14 16 18 20 22 24 I2# 16% isy 2 2oy 2 22 i y 2 24^ 14 16 18 18 24 24 30 30 60 80 no 140 200 260 310 400 io6 RIX AIR COMPRESSORS. i\ RTX AIR COMPRESSORS. I08 RIX AIR COMPRESSORS. RIX STEAM ACTUATED VERTICAL COMPRESSORS. Ceass H, Fig. 47. This style of compressor is one which has given universal satisfaction in this State, a machine of similar type having run continuously from 1880 to the present date with no expense whatever beyond valve springs. It is single acting; the air cranks being placed at 180 degrees from each other, which balances the machine completely, and the cylinders being ver- tical there is no internal wear of any consequence. The steam engine is placed horizontally on the floor, for the double pur- pose of keeping the warmth of the steam cylinder away from the inlet air, and also for the purpose of making the steam crank at right angles to the air cranks. This compressor is made in only one size: 12-inch steam cylinders, 12^-inch air cylinders by 16-inch stroke, and catalogued No. 58. Capacity in free air per minute, see page 84, both cylinders being the equivalent of one double-acting 12^-inch cylinder, as per table. Figs. 48, 49, and 50 show different views of this same machine. RIX AIR COMPRESSORS. I09 . 47— Class H.— Rix Steam Actuated Vertical Compressor. Manufactured by Fulton Engineering and Shipbuilding Works, San Francisco. RIX AIR COMPRESSORS. Fig. 48— Class H.— Rix Steam Actuated Vertical Compressor. Manufactured by Fulton Engineering and Shipbuilding Works, San Francisco. RIX AIR COMPRESSORS. Fi3. 49— Class H.—Rix Steam Actuated Vertical Compressor. Manufactured by Fulton Engineering and Shipbuilding Works, San Francisco. RIX AIR COMPRESSORS. Fig. 50— Class H.— Rix Steam Actuated Vertical Compressor. Manu- factured by Fulton Engineering and Shipbuilding Works, San Francisco. RIX AIR COMPRESSORS. 113 RIX SINGLE CORLISS ACTUATED COMPRESSORS. Class I, Fig 51. These Compressors consist of a Standard Corliss engine, to which there is placed tandem the air cylinder. Fig. 52 shows a plan of the single machine. They are an economical and high-class machine in every respect. The following table shows the sizes and dimensions of the Class I,;Rix Single Corliss Actuated Compressors: RIX SINGLE CORLISS ACTUATED COMPRESSORS. CLASS I. For Revolutions per minute, Capacity Free Air, Rock Drill Capacity, see pages 84 and 85. 59 60 61 62 63 64 65 66 67 68 69 70 7i 72 73 74 St'm Cylinder. 16 16 16 16 16 16 18 18 18 18 ]8 18 Diameter Air Cylinder. 12^ i6# 16^ i8# 18K 16^ i8# i8# 20>£ iSj4 2o>£ 18K 20K 30 30 30 30 30 30 36 36 42 42 36 36 42 42 48 RIX AIR COMPRESSORS. RIX AIR COMPRESSORS. Il6 RIX AIR COMPRESSORS. RIX COMPOUND CORLISS ACTUATED COMPRESSORS. Class J comprises the Rix Compound Corliss Acttiated Com- pressors^ which are entirely similar to those of Class I excepting that the steam cylinders are compound, the air cylinders being alike. The following is a table showing the sizes and principal dimensions of the Class J Compressors: RIX COMPOUND CORLISS ACTUATED COMPRESSORS. CEASS J. For Revolutions per minute, Cubic Feet Free Air, Rock Drill Capacity, see pages 84 and 85. No. Diameter High Pressure. Diameter Eow Pressure. Diameter Air Cylinder. Stroke. Price. 75 12 22 12^ 30 76 12 22 14^ 30 77 f4 26 14^ 30 78 14 26 16^ 30 79 16 30 l6>^ 30 80 16 30 l8>^ 30 81 16 SO 16^ 36 82 16 30 i8/ 2 36 83 16 30 16^ 42 84 16 30 isy 2 42 85 18 34 isy 2 36 86 18 34 20 l / 2 36 87 18 34 isy 2 42 88 18 34 20 l A 42 89 18 34 isy 2 48 90 18 34 2oy 2 48 Both the Compressors Class I or Class J are furnished either condensing or non-condensing. RIX AIR COMPRESSORS. RIX LIGHT DUTY COMPRESSOR OR VACUUM PUMR Ci,ass K, Fig 53. This Compressor is adapted for very light work and is a self-contained machine working from a Scotch yoke. It is intended for pressures up to 25 lbs. only, and can be either used as a compressor or a vacuum pump, the valves being arranged for that purpose. It is single acting and the dis- charge is absolutely complete, there being no clearance what- ever. It is capable of creating a 2g-inch vacuum. Made in four sizes having 4 7/ , 5 /7 , 6 // , and 7 7/ diameter of cylinders, and catalogued No. 91, 92, 93, and 94 respectively. This machine is a very inexpensive and satisfactory com- pressor to have in laboratories, shops, and canneries, or for blowing crude oil into furnaces. A four-inch belt is ample to run any of them. The peculiar feature which is advantageous as a vacuum pump is the discharge valve which covers the whole end of the cylinder. The piston touches it, moves it slightly from its seat, thus dispelling all the air, the valve reseating as the piston begins the return stroke. RIX AIR COMPRESSORS. Fig. 53— Class K.— Rix I^ight Duty Compressor or Vacuum Pump. RIX AIR COMPRESSORS. 119 RIX STEAM ACTUATED DUPLEX COMPRESSORS. Class Iv. These compressors are designed for compressing air to not exceeding twenty-five pounds per square inch, with a steam pressure at from sixty to ninety pounds. They are made with Scotch Yoke, as may be seen from the cut in Fig. 54, and are self contained in every respect. They are especially adapted for this Coast, for furnishing air for burning crude petroleum or distillate. These machines are far heavier and stronger than any machine which is built in the East for the same purpose; the same comparative cylinder sizes being made about twenty-five per cent heavier, so that for use on shipboard they may be absolutely relied upon not to break or give out when at service. These machines are complete with all lubricators, valves, and also automatic governor, which will regulate the machine to within two or three pounds of the receiver pressure. Kach one of these compressors is set up in the shop and thoroughly tested before shipment, so that the machine will be ready to go to work as soon as set upon its foundations. The following are the sizes of the Rix Steam Actuated Duplex Compressors, Class L ; RIX AIR COMPRESSORS. RIX AIR COMPRESSORS. RIX STEAM ACTUATED SINGLE AIR COMPRESSORS. Cl,ASS M. These machines are precisely like those of Class L,, except- ing that they are Single instead of Duplex, and are fitted up in precisely the same manner. They are complete with governor, lubricators, oilers, and wipers. Each machine is tested before leaving the shop, so that it is ready for work immediately it is erected upon its foundations. The following are the sizes of the Rix Steam Actuated Single Air Compressors, Class M : RIX AIR COMPRESSORS. -ISAIOJ 3SJOH •3irxnxj\[ asd axy aa-itf }3<3^[ oxqn^ 10 r^ O ro O •saqoui lit 3§-lBipSI(I J.IV W rO •saipui m l-snxi axy CN O Ol •saxpixi in }sixbi[Xk£ xxxBais •saxpui UT Arddng uxB3is •saqoui ux s^oa^e; jo xj.}£ii3l vO r-» i>» o> C^ C^ •saipxxi ux .xapixx •\&d JXV J313XXXBXQ ^O t^ CO On O ^h •S3X|0UI xxi japux -1^0 uiBaas ab^aaxBia ^t- to lO v£> !>. o> RIX AIR COMPRESSORS. 123 J3MOJ 3SJOH 04 ro rO IO jad snopnxoAa-a •saipui in 3g.reipsia -»V « ro •saqoui ni ^\uj axv OJ CN CS rO ■S3XIDUI III ^sriBuxjj xuBa;s •S3t[0UI ux Xjddns raB3;s >S •S3H0UI MD r^ r^ o\ c^ On •saxpni in jap -uyi^o jiy Jajauma VD t^ CO a\ "* •saipni in japin "* to 10 vo t^ On 124 ■RIX AIR COMPRESSORS. Class N, Fig. 54— Duplex Direct Acting Steam Actuated Compressors. DUPLEX DIRECT ACTING STEAM ACTUATED COMPRESSORS. Ceass N. It will be noted from the cut, Figure 54, that these com- pressors are made after the style of the DIRECT ACTING STEAM PUMP, and they are designed to meet certain require- ments where light pressures and inexpensive or temporary machinery are desired. They are the least expensive of all com- pressors which are built, and while they do not have a very high volumetric efficiency, they are easily installed and for cer- tain classes of work are amply economical. The AIR CYLINDERS are composition lined and the PIS- TON rods are of brass. Every machine is fitted complete with its PROPER LUBRICATOR and wrenches. The VALVE MECHANISM is so arranged that the air pistons work against a constant pressure at all times, thus obtaining quite a high efficiency for this character of compressor, and insuring a uni- form stroke. There are no DEAD CENTERS on the machine, and the pump is consequently always ready to start. The dispensing of the crank and flywheel renders it possible to place this com- pressor in an extremely small space. RIX AIR COMPRESSORS. 1 25 The VALVES in the steam end are slide valves, and in the air and poppet valves of the ordinary type positively con- trolled by the valve mechanism. The entire apparatus is com- pact, durable, and self-contained. There are no intricate working parts whatever, and it requires very little attention to operate it. As a general rule it is desirable to operate this machine in connection with a PRESSURE REGULATOR, which we fur- nish with the machine if desired. The PRESSURE REGU- LATOR automatically controls the speed, slowing down and finally stopping the pump when the desired air pressure is ob- tained, and gradually starting up again when the air is ex- hausted from the reservoir. This regulator practically makes the machine automatic in its operation. This Compressor is used in BREWERIES for BEER RACKING, and is especially desirable for that purpose. It is also used in running PNEUMATIC TOOLS for cutting mar- ble or granite, or other building stone, and also for CHIPPING and CALKING BOILERS; for the running of SAND BLASTS; for the handling of ACIDS in refineries; for running small PNEUMATIC CRANES; for use in RUBBER FACTORIES, or for pumping pressures upon AUTOMATIC FIRE EXTIN- GUISHERS; for CLEANING CARS where a jet of air is used to dust off cushions it is especially valuable as an inexpensive and cheap machine; for the running of CLIPPING MA- CHINES, or for running COAL CONVEYORS, or SMALL ROCK DRILLS, where pressures not exceeding fifty or sixty pounds are required; for PNEUMATIC EJECTORS, or for producing vacuums for FILTERING purposes; and the enum- erable requirements where low pressure compressed air is desired. For RUNNING ROCK DRILLS we do not advocate it for a permanent plant, but for a prospecting plant for small drills, these compressors can be readily installed and will prove first- class in their operation. These Compressors are particularly adapted for furnishing the compressed air to BURN PETROLEUM COMPOUNDS UNDER BOILERS FOR GENERATING STEAM. 126 RIX AIR COMPRESSORS. DUPLEX DIRECT ACTING COM- PRESSORS. Class N. Capacities calculated on piston speed of 60 feet and volu- metric efficiency of 70 per cent. No. S s si a-M a g«J a Q U © 35 Cubic Feet of Free Air. 4 3X 5 2.8l X I 50 112 5X 4 5 3.68 X I 50 113 5X 4X 5 4-65 X I 45 114 5X 4X 5 5.o6 X I 40 115 5X 6 5 8.28 x I 20 Il6 6 3 6 2.07 IX 70 117 6 3^2 6 2.8l iX 60 Il8 6 4 6 3-68 *x 55 119 6 4X 6 4.65 iX 50 120 6 4X 6 5.06 iX 45 121 6 6 6 8.28 iX 40 122 6 6^ 6 9.70 iX 30 123 6 7 6 II.27 iX 25 124 6 7X 6 13. iX 20 125 6 8 6 14.72 iX 15 RIX AIR COMPRESSORS. 127 PNEUMATIC GOVERNORS. Fig. 54/^ shows the Pneumatic Governor which the Fulton Engineering Company attach to all the Corliss Compressors. This Governor consists in a special attachment arranged in connection with the Standard Corliss Governor, which is actuated by the air pressure. When the pressure rises in the air receiver the Governor balls are automatically lifted and the hooks are thus tripped independently of the number of revolutions which the engine is making. When the pressure falls in the tank the device drops out of the way and the engine is controlled by the Corliss Governor pure and simple. For all ordinary compressors, when desired, a Governor is furnished which controls the admission of steam readily as the load varies. It is simple and effective in its operation. 128 RIX AIR COMPRESSORS. gfc u.9 THE RIX COMPOUND COMPRESSOR. In speaking of the various means in practise for cooling the air during its compression, reference has been made here- tofore in this treatise to compounding the compressing cylin- ders. The advantages of this process are so important that it has come into general use and Compound Compressors nowa- days are beginning to be the rule rather than the exception. It is therefore interesting to give some explanation of this method of compression. The principle of Compound Compression can be described as follows: Suppose that a certain volume of air at atmospheric pressure and temperature is to be raised to a certain pressure and delivered into a receiver; in ordinary, or single stage compression, this air is introduced into a cylinder wherein a piston effects the compression and delivery of that air at each stroke. This compression, as we know, and especially in fast moving machines, is accompanied by a considerable develop- ment of heat, which causes a loss of efficiency. In the compound machine, air is adm tted into a cylinder, as before, but it is compressed and delivered into a receiver at a pressure smaller than the desired final pressure. In this first period or stage of compression there is a certain amount of heat developed, less, however, than in the single stage ma- chine. The compressed air, after it is delivered into this first receiver at the intermediate pressure, is cooled by coming in contact with a number of copper tubes through which cold water is rapidly circulated. This receiver is quite similar to the surface condenser used in marine engines and is termed the Intercooler, and the compressed air leaves it after having been deprived of its heat, and reduced to practically the tem- perature of the water. It is then admitted into another smaller cylinder wherein its pressure is raised by another piston — the air being again passed through another intercooler — then ad- mitted into a third cylinder, and so on until the final desired pressure is reached. The compression of air, instead of being affected all at once, is therefore performed in several stages, each separated from the following one by a cooling to the atmospheric temperature. It may be readily conceived that the partial amounts of heat developed in this series of cylinders are more effectively dealt with than when the whole amount of heat is liberated in a single cylinder. On this ground the Compound Compressor will therefore possess a higher efficiency than the single stage machine. Another advantage is that the variation of load on the piston during the stroke is less in the compound, and conse- quently the strains on the crankpins are reduced, and a lighter 130 THE RIX COMFOUND COMPRESSOR. THE RIX COMPOUND COMPRESSOR. I3I flywheel will regulate the motion of the machine than is the case in a single-stage compressor. For instance, if we use a 12-inch cylinder to compress air to 100 lbs. gauge, in the single- stage compressor, the load on the piston during one stroke will vary from o to 11,300 lbs., whereas in the compound ma- chine this load can be made to vary from o to 5960 in all. The principle of the Compound Compressor applies to any number of successive stages, and, theoretically, the more stages there are used the nearer will the compression approach the isothermal. But, at a practical standpoint, the increased number of cylinders is, of course, objectionable, inasmuch as it makes a heavier and more intricate machine, which will cost more and necessitate more expenditure for maintenance. The frictional resistances also become greater with the number of cylinders, and it is, therefore, readily seen that there are some practical limitations in the use of this system. It may be stated that for pressures not exceeding 200 and even 300 lbs. per square inch, there should not be more than two stages in the compression. Four stages is the limit which has not been thus far exceeded, even with air pressure reach- ing to 2000 lbs. per square inch, and even for these high pres- sures three-stage compressors are deemed amply sufficient. On the other hand, the compound system would be an unnecessary improvement with low pressures. For 50 or 60 lbs. receiver pressure it is quite likely that the percentage of extra resistances would balance if not overcome the percentage of gain in cooling. In general, the advantages of a compound system consist in that less heat is developed at each stroke of the piston, while the air under compression is exposed to a larger cooling sur- face than in a single-stage machine. The diagram, Fig. 56, represents the theoretical adiabatic cards of a 12x16 single stage compressor and of a tandem com- pound 12 and 73^x16, both compressing to 70 lbs. gauge. It also shows the expansion curve in a 12x16 steam cylinder de- veloping with steam at 80 lbs. gauge the same work as the single stage compressor. These cards do not show the variations of pressure of steam and air, but the variations of effective load on the piston rod of the three cylinders, and they will serve for a comparison of two direct-acting steam compressors — one in the single stage and one in the compound system. We know already that the aggregate piston load in the com- pound is less than in the single machine and as the initial loads are o in both cases, the range of variation is less in the compound. This allows a reduction in the size of the piston rods. It will be noticed that the compound curve has a sharper rise, since the maximum load H. G. is reached at the point / of the stroke, while in the single cylinder this same load is only reached at the pointy. The result of it is that during this portion of the stroke, which precedes the point of equal loads in the two compressors, i. e., the point of intersection of 132 THE RIX COMPOUND COMPRESSOR. THE RIX COMPOUND COMPRESSOR. 133 the steam and air curves, the difference of the load between the steam and air pistons is smaller in the compound, where it is 6" V for instance, than in the single cylinder compressor, where at the same point T, of the stroke, the difference is 5 V. The same may be said for the second portion of the stroke, except in the region// 7 , but here the discrepancy is unim- portant, the piston loads being but little at variance in the two compressors, and this region corresponding to the maximum velocities of the pistons. As the mass of moving pieces, whose momentum is resorted to for securing a regular motion, is a function of the actual dif- ference between the steam air piston loads, lighter regulating pieces, like flywheels, will be required in the compound than in the single compressor. The same size of steam cylinder will be found adopted in practise with both kind of compressors, the point of cut off being, moreover, variable. A longer expansion of steam, combined with a less weight of machine, combine to win for a compound compressor the deserved claim of being a better balanced and more economi- cal machine than the single stage. It will be seen that a proper design of such machines must tend to an equal division of the total work among the several cylinders; that the loads are equal on each one of the pistons at any point of the stroke, and that the temperature of the entrance and exit of the air are the same in all the cylinders. The following table shows the percentage of gain obtained by compounding as against the single-stage system, with various modes of compression: PERCENTAGE OF GAIN OF 2-STAGE VS. I-STAGE SYSTEMS OF COMPRESSION. Ratio of Receiver pressure to atmos- pheric pressure. Gain per cent in: Adiabatic Compression (no cooling). Jacketed Cylinders Jacketed Cylinders cooled by spray in- jection in the most efficient way possible n-5 8-95 6.4 12.5 13-8 14.8 11. 8 7 5 8.2! 8.7 15.9 12.5 9.2 These figures show that for the usual air pressures the amount of work saved by compounding varies from 9 to 12 per cent. This is by no means a quantity to be neglected. 134 The rix compound compressor. We also note that the advantage of compounding increases with the pressure and is more marked with a poor than with an improved system of cooling. The Fulton Engineering and Shipbuilding Works do not issue a list of the various sizes of their Compound Compressors, for the reason that the relation between the two cylinders can never be fixed, the sizes of the initial cylinders depending of course upon the quantity of air required, and the size of the compound cylinders depending entirely upon the pressure desired. Special estimates and specifications are furnished with each compound machine. The following illustrations show some of the compound machines built by the Fulton Engineering and Shipbuilding Works, and give an idea of their general style. The Compound Compressor, Fig. 60, shown in the preced- ing cut, illustrates the general style of the Compound Com- pressors built by the Fulton Engineering and Shipbuilding Works. This Compressor was built for the North Star Mining Company, of Grass Valley, Cal., and consists of Duplex Tan- dem Compound machines. The initial cylinders are 18 inches in diameter, and the high pressure cylinders are 10 inches in diameter by 24-inch stroke. The piston speed of the machine is 440 feet, which, while not quite as economical as one much lower, was dictated by the conditions under which the water wheel operated. The air enters the initial cylinder at the temperature of the power room, which is approximately 62 degrees, and is therein compressed to 25 lbs. to the square inch gauge pressure. It leaves the cylinder at a temperature of 200 degrees Fahr. and passes through an intercooler of about 1000 running feet of 1- inch copper tubes placed directly beneath the water wheel, and which receives from the wheel a continual shower of water at a temperature of about 58 degrees. This cools the air to such an extent that it is delivered to the high pressure cylinders at a temperature of about 60 degrees. In these cylinders the air is compressed to 90 lbs. and is delivered from the cylinders at a temperature of 204 degrees into 6-inch mains, which lead to the mine. Indicator cards taken from the cylinders show that the cylinders are doing equal work, and at no revolutions they work smoothly and perfectly. Notwithstanding the fact that some builders claim that clearance has no detrimental effect upon the economy of their air compressors, in the Rix compressors the clearance is prac- tically eliminated, being not to exceed one-thirty-second of an inch at each end of the stroke. The cards taken from these cylinders are practically square-cornered. The water-jacket system is quite unique, it being a duplex system — that is, there is an independent circulation for each end of the cylinder, the water passing longitudinally back and forth on the side of the cylinder and from the center in two I' THE RIX COMPOUND COMPRESSOR. 135 -|s ^ssj -i=- # 136 'The: rix compound compressor. THE RIX COMPOUND COMPRESSOR. 137 138 the; rix compound compressor. THE RIX 'COMPOUND COMPRESSOR. 139 independent streams, cooling the heads at the same time. The efficacy of this water jacket will be noted in the temperatures above given. In testing for volumetric efficiency, the receivers were care- fully measured a number of times and found to contain 291 cubic feet. These were filled repeatedly, and the number of revolutions of the machine accurately counted each time. All of these experiments were conducted after the machine had been in operation for a sufficient length of time to reach its maximum temperature. The barometer at the power house is 27.35 inches, corre- sponding to an elevation of about 2400 feet. This gives an atmospheric pressure of 13.32 lbs. per square inch. At 90 lbs. gauge pressure the ratio of compression would be 7.7, and the receiver containing 291 cubic feet represents 2240 cubic feet capacity of free air. The average of a great many experiments showed that the compressor took 102^ revolutions to fill the receiver from 25 lbs, which is the pressure of the initial cylin- der, to 90 lbs. At this pressure of 25 lbs. gauge there is 830 cubic feet of free air in the receiver. The difference between these two capacities, or 1410 cubic feet, would represent the imount of air which was forced into the receiver at the revolu- tions stated. Inasmuch as the temperature of the receiver is somewhat higher than the temperature of the inlet air, there should be a deduction made from this sum corresponding to that temperature of about two per cent, making the corrected amount delivered to the receiver 1382 cubic feet. The theoretical capacity of the compressor, deducting the piston rods, and at 102^ revolutions, is 1429 cubic feet of free air per minute. The ratio between 1382 cubic feet, actually delivered, and 1429 cubic feet, theoretical capacity, is 96.6 per cent, which represents the actual volumetric efficiency of the machine at the present writing. This of course will vary pro- portionately with the ratios of the absolute temperatures of the inlet air, depending upon the season of the year. One peculiarity about the Rix Compressor, as may be noted from the cut, is the fact that the compressor is so arranged that any cylinder may be disconnected or any end of any cylinder may be disconnected without interfering with the operation of the machine. This feature is very valuable in case of repairs or accident to the machine. To drive this compressor there has been placed upon the main shaft a Pelton water wheel, eighteen feet in diameter, which is believed to be the largest tangential water wheel ever made. THE PNEUMATIC TORPEDO PLANT AT THE PRESIDIO. (Originally published in "Journal of Electricity," S. F.) The recent tests made by the military authorities on the dynamite guns at Fort Point may lend some interest to a few particulars regarding the Air Compressing Plant which forms the vital element of this installation. The contract for the construction of the mechanical part of it, with the exception of the guns and their immediate fixtures, was awarded by the Pneumatic Torpedo and Construction Com- pany of New York to the Fulton Engineering and Shipbuild- ing Works of this city, upon the plans and special designs of Mr. E. A. Rix, who supervised the construction of the plant. The compression of" air is made in three stages, from the atmosphere to the working pressure of 2000 lbs. effective per square inch. It is performed in two sets of horizontal engines, to both of which the subsequent description applies, they being in all respects entirely alike. The steam is supplied by four boilers of the Horizontal Tubular type, of 750 H. P. capacity, arranged to work either with natural or with forced draught. Two steam cylinders connected to the same shaft by cranks at an angle of 145 degrees from each other, actuate in tandem, that is, through their piston tail rods, each two air cylinders, there being on one side one low pressure and the intermediate or second stage cylinder, and on the other side one low pres- sure and the high pressure or finishing cylinder. This duplex set therefore comprises two steam cylinders, two intake cylinders, wherein the atmospheric air is compressed to about 75 lbs. effective, one intermediate cylinder, carrying the air pressure from 75 to about 400 lbs. effective, and one high pressure cylinder, which takes the air at 400 lbs. and com- presses it to 2000 lbs. effective. The intake or low pressure cylinders are double acting, that is, they have inlet and discharge valves at each end, while the intermediate and high pressure cylinders are single acting, that is, provided with valves at one end only, their pistons being plunger rams with spherical heads, connected to the tail rods of the intake cylinders. The special purpose which these compressors have to serve made their design and construction subservient to conditions at entire variance with the lines upon which an air compressing plant is usually established. The main object of the designer, when a large power is to be used, as in the case of the Fort Point installation, is commonly to secure the greatest possible economy in the production of the compressed air. In the pres- ent instance, compound condensing engines of the most approved type, and air cylinders working at a moderate linear THE PNEUMATIC TORPEDO PIl» m -it oo in - » ~ ' < cy NO rn (Olt N 00 to to 00 -IT I CO - X Qr .£ V o — o > IT s (^ o.^ i 2 Is s _i >/> X u sO «J > t! X J r 0" TJ el C- Q ri 4. __, s 5 « 0) >- i ?-> Q> Cf- c_ . J 3 X vA a> U V- 3 o 3 c> >- 1 .0 oJ 'fi- ll- 3 ■* s *0 }- > o V i2» ^ i. _£ 5 4 «l JL 0> 5 en v 5 en (D> f 1 I o) ^ J 5 s -J x Q 0) 5 2 V u5 D N CO ROCK DRILLS. 171 -M -W t> fe K O tf ti ^ ■J b h ■« <-*_ > ^ a. -7 = s j — - 2 >i =■ i a: .Q- -O £ x A el - _J I at L ^> 0/ _C s s _, iu" 6 2 -TJ * '3 cr j- 's 2 <* Q J) J. >1 *l M3 0) '5_ 5 (J 'q- S J -c T h s "a u 5 SO 3" 15 3 s £ d 1 .0 el V £_ ■i c*_ al o_ > Cj- £_ V »- If) 0) CO « in 172 ROCK DRILLS. DUPLICATE PARTS OF THE RIX ROCK DRILLS. i — Rotating Nut. 2 — Piston, bare. 3 — Piston Ring. 4-5 — Sleeve. 6 — Feed Nut (adjustable). 7 — Feed Nut (plain). 8— Yoke for Feed Nuts. 9 — Lower Head. 10 — Leather Crimp for Lower Head, ir — Chuck Bolts and Nuts. 12 — Chuck Bushing. 13 — Chuck Key. 14 — Steam Chest, bare. 15 — Main Valve. 16 — Steam Chest Cap. 17— Steel Cushion Plate. 18 — Rubber Cushion. 19 — Auxiliary Valve. 20 — Auxiliary Valve Spring. 21 — Auxiliary Valve Claw. 22 — Oil Screw. 23— Yoke for Head Bolts. 24 — Head Spring. 25 — Cover for Ratchet Ring. 26 — Bottom Plate for Ratchet Ring. 27 — Rotating Bar. 28 — Cylinder, bare. 29— Guide Block. 30— Shell Strip. 31 — Cylinder Bolts. 32— Shell Bolt. 33 — Feed Screw. 34— Yoke for Shell Bolts. 35 — Feed Screw Handle (brass). 36 — Pawl. 37 — Ratchet Ring. 38 — Pawl Spring. 39 — Shell without Strips or Yoke. 40 — Clamp Wrench. 41— Steam Chest Wrench. 42 — Chuck Wrench. ROCK DRILLS. 173 DUPLICATE PARTS OF THF, R1X ROCK DRILL. ROCK DRILLS. duplicate; parts of the giant DRir.r y . ROCK DRII^S. 175 DUPLICATE PARTS OF THE GIANT ROCK DRILLS. 1 — Rotating Nut. 2 — Piston, bare. 3 — Piston Ring. 4 — Valve Chest. 5 — Valve Chest Cover. 6 — Feed Nut (adjustable). 7 — Feed Nut (plain). S— Yoke for Feed Nuts. 9 — Lower Head. 10 — Leather Crimp for Lower Head. 11 — Chuck Bolts and Nuts. 12 — Chuck Bushing. 13 — Chuck Key. 14 — Valve. 15 — Valve Rocker. 16 — Piston Ring Spring. 17 — Rocker Pin. 22 — Oil Screw. 23 — Yoke for Head Bolts. 24 — Head Spring. 25 — Cover for Ratchet Ring. 26— Bottom Plate for Ratchet Ring. 27 — Rotating Bar. * 28 — Cylinder, bare. 30— Shell Strip. 31 — Cylinder Bolts. 32— Shell Bolt. 33 — Feed Screw, 34— Yoke for Shell Bolts. 35 — Feed Screw Handle (brass). 36 — Pawl. 37 — Ratchet Ring. 38— Pawl Ring. 39 — Shell without Strips or Yoke. 40 — Clamp Wrench. 41 — Steam Chest Wrench. 42 — Chuck Wrench. 176 ROCK DRILLS. RIX PLUG AND FEATHER DRILL. The Rix Plug and Feather Drill, a cut of which appears in Fig. 66^, is the smallest drill manufactured by this Company. It has a two-inch diameter cylinder, from four to five inch stroke, and makes from seven hundred to nine hundred strokes per minute. It is designed for drilling small holes about one inch in diameter and for depths up to twenty-four inches. For quarry work it is mounted on a tripod, as shown in the cut, and for mining purposes it has the usual column mountings. The tripod is one which gives a wide range of movement. The Drill itself weighs about 65 lbs. and is extremely con- venient to handle. It is generally used with seven-inch steel and the chuck is made tapering to take the end of the steel in similar to the way a twist drill fits in its socket. This will be found most convenient in the handling of these small drills. This machine will tfe found very handy for many ranges of work, including the driving of wooden pins in caison, scow, or dry dock constructions where the pins have to be driven from underneath the work being constructed. In the use of air it is very economical, taking about twenty- five cubic feet of free air per minute. ROCK DRILLS. 177 u Fig. 65y 2 — RIX PLUG AND FEATHER DRII,!,. A FEW GENERAL HINTS. Buy a Compressor larger than you need. Buy one which is economical. Run it slow. Put in good foundations. Have a spare boiler if you can afford it. Have a clean, ship-shape engine-room. Cover all of your steam-pipes. ' Provide large air-pipes. A generous sized receiver will come in handy. Make as few short turns as possible in the air-pipe. Use a good cylinder lubricant. Circulate ample water in the air cylinder jackets. Have some extra compressor valves, and change them fre- quently. Put in one or two shut-off valves in your air-pipe. Keep the receiver properly drained. Buy a rock drill of a size best suited to the work, and don't buy any unless your mind is made up to do it properly. Have plenty of steel, so your men are not running for drill-bits all the time. Get a good blacksmith, and have him keep both ends of the steel properly sized. Drill good-sized holes, for the powder does better work at the bottom of a hole. Have an intelligent workman to run the drill. Have an extra drill always ready in the shop, and you will find less breakages and accidents occur to those in use. Oil the machine well before starting. See that all the nuts are tight. Be sure that no dirt is in the hose before it is attached to the machine. Keep the column well jacked up, and have blocks of wood top and bottom. Start the holes on the shortest stroke of the machine, and gradually lengthen out the stroke as the hole deepens. Feed the machine so that the piston will clear the front head. A FKW GENERAI, HINTS. 179 In soft ground, make haste slowly. If the steel gets stuck in the hole, strike it sharply until it releases. Never strike the chuck. Do not screw up too hard on the chuck-nuts or clamp-bolts, for it is perfectly possible to break them. Keep your bushings in good order. A bit of cast-iron or iron borings thrown into a fissured hole will help it out. A piece of broken drill-bit will often cause a hole to run out. Drill wet holes whenever you cau. A leaky stuffing-box will often prevent the piston pulling out from a tight hole. Never run the drill against the head to throw the steel out. Do not expect the drill to furnish brains to run itself. Do not expect it to run without repairs. Carry as high a pressure as possible when your rock is hard, and calculate always that the repairs will vary, as the pres- sure and also the work done. Remember that a rock drill is an engine, after all, and the fewer times it goes over the dump, or is dropped off the column, or is blasted upon, the longer it will last. Generous and faithful oiling will help a machine wonderfully. Use a good steam-trap when using a drill in a quarry. A tripod must be securely set to do good work. The same kind of drill-points do not work equally well in different kinds of rock. i8o ROCK DRILLS. Fig. 67.— Column with Arm Fig. 68.— Plain Column. Column Mountings for Rock Drills. Made in any length. One price for all lengths under ten feet. ROCK DRII^S. 181 AIR RECEIVERS. In conjunction with an air compressor there is generally- attached a reservoir called an air receiver. The purpose of this is twofold: to collect the moisture which is condensed from the air after it is compressed, and also to afford a sufficient volume to receive the intermittent discharges from the compressor, and reduce them to a continuous flow in the pipes leading from the receiver. The ordinary receiver is fitted with an air gauge, a safety valve, and a valve to draw off the moisture. These are arranged as shown in the cut herewith attached. Our reservoirs are made of homogeneous steel, with bumped heads, of a sufficient thickness to be tight at 125 lbs. cold water pressure, for all ordinary plants. We prefer bumped heads because bracers are not then necessary. We put three cast iron feet on one end of the receiver for it to stand upon, and sufficiently high to permit drawing off the entrained water water easily, above the floor line. We are frequently asked where is the proper place for the receiver — at the compressor or in the mine ? We reply, both. There never was too much receiver capacity on any plant. We do not believe it essential to have a very large receiver near the compressor, providing there is an oppor- tunity to place one further along the pipe. About fifteen times the cylinder capacity would, in all ordinary cases, keep the gauge steady at the compressor. It would be a great benefit to systems having medium or small size pipes to have as large a receiver capacity at or near the point where the air is used, and especially is this the case where hoisting engines are drawing from the air pipes. It requires no engi- neering knowledge to see that if air receivers could be made large enough to diffuse the intermittent work into an average draw on the pipe leading from the compressor, that the com pressor need be only large enough for the average work, whereas ordinarily it must be large enough for the maximum work, and consequently uneconomical. It is not generally practicable to have reservoirs so large, however, but a reasonable approach can be made to this capa- city without much expense. We have known compressors to do 25 per cent more useful work by putting receivers near the point where the air is to be used, and where numerous bends and elbows are required in the main pipe. When air is drawn too fast through the main pipe, causing a reduction, of pressure, the increase of volume due to the loss pressure causes quite a marked increase in all the frictional losses through the system. We therefore advise receivers at both ends of the line, the smaller ones near the compressor, and this is independent of the amount of storage capacity in the pipe. AIR RECEIVERS. DIMENSIONS OF AIR RECEIVERS. Diameter, inches 30 30 36 36 36 42 Height, feet 6 8 8 io 12 8 Thickness of Shell, inches . }( % % % % }( Thickness of Heads, inches. Xe s At Y& Y% % % « Weight 700 900 1200 1400 1600 1800 No. of 3>(-i n ch Drills Re- ceiver is suitable for 11 2 3 4 5 Diameter, inches 42 42 42 48 48 48 Height, feet 10 12 16 10 12 j6 Thickness of Shell, inches. % % % y it s / lt c / t Thickness of Heads, inches Y& Y& Ys yU %e Yit Weight 1900 2000 2100 2400 2900 3400 No. of 3X-inch Drills Re- ceiver is Suitable for S 10 12 12 15 20 AIR RECEIVERS. toxccooooooo oooo o o c (puroooooooo o o qoooooooooooqcchu 88 44 19 86 85184 .022727273 94 88 36 830584 .010638298 45 20 25 91125 .02.4222222 95 90 25 857 375 .010526316 46 2116 97 336 .091739130 96 9216 884 736 .010416667 47 22 09 103 8*3 .021276600 97 94 09 912 673 .010309278 48 23 04 110 592 .020K33333 98 96 04 941192 .OK); 04082 49 24 01 117 649 .020408163 99 98 01 970299 .010101010 50 25 CO 125000 .020000000 100 10000 1000000 .010000000 196 USEFUL TABLES. SQUARES, CUBES AND RECIPROCALS— Continued. Hos. Squares. Cubes. Reciprocals. Nos. Squares. Cubes. Reciprocals. 101 102 01 1030 301 .009900990 151 2 28 01 3 442 951 .006622517 102 104 04 1 061 208 .009803922 152 2 3104 3 511808 .006578947 103 106 09 1 092 727 .009708738 153 2 34 09 3 581 577 .006535948 104 108 16 1 124 864 .009615385 154 2 37 16 3 652 264 .006493.506 105 110 25 1 157 62} ,009523810 155 240 25 3 723 875 .006151613 106 112 36 1 191 016 .009433962 156 243 36 3 796 416 .006410256 107 114 49 1 225 043 .009345794 157 2 46 49 3 869 893 .006369427 106 116 64 1 25^ 712 .009259259 158 2 49 64 3 944312 .006329114 109 118 81 1 295 029 .009174312 159 2 52 81 4 019 679 .006289308 110 12100 1331000 .009090909 160 256 00 4 096 000 .006250000 111 1^23 21 1 367 631 .009009009 161 2 59 21 4173281 .006211180 112 125 44 1 404 928 .008928571 162 2 62 44 4 2515 8 .006172840 113 127 69 1 442 897 .008849558 163 2 65 69 4 330 747 .006134969 114 129 96 1 481 544 .008771930 164 2 68 96 4 410 944 .00609-561 115 132 25 1 520 875 .008695652 165 2 72 25 4 492125 .006060608 116 1 34 56 1 560 896 .008620690 166 2 75 56 4 574 296 .006021096 117 136 89 1601 6 L3 .008547009 167 2 78K9 4 657 463 .005988024 118 139 24 16*3 032 .008474576 168 2 82 24 4 741 632 .005952381 119 14161 1 685 159 .008403361 169 2 85 61 4 826 809 .005917160 120 144 00 1728 000 .008333333 170 2 89 00 4 913 000 .005882353 121 146 41 1 771 561 .008264463 171 2 92 41 5000211 .005847953 122 148 84 1 815 848 .008196721 172 2 95 84 5 088 448 .005813953 123 15129 1 860 867 .008130081 173 2 99 29 5 177 717 .005780347 124 153 76 1 906 624 .008064516 174 3 02 76 5 268 024 .005747126 125 156 25 1 953 125 .008000000 175 3 06 25 5 359 375 .005714286 126 1 58 76 2 000 376 .007936508 176 3 09 76 5 451 776 .005681818 127 16129 2 048 3S3 .007874016 177 3 13 29 5 545 233 ,0i 156(9718 128 163 84 2 097 152 .007812500 178 3 16 84 5 659 752 .005617978 129 166 41 2 146 6S9 .007751938 179 3 20 41 5 735 339 .005566592 130 169 00 2 197 000 .017692308 180 .3 24 00 5 832 000 .005555556 131 17161 2 248 091 .007633588 181 3 27 61 5 929741 .005524862 132 1 74 24 2 293 968 .007575758 182 3 3124 6 028 568 .005494505 133 176 89 2 352 637 .007-il8797 183 3 34 89 6 128 487 .005464481 J 34 179 56 2 406 104 .007462687 184 3 38 56 6 229 504 .005434783 135 182 25 2 460 375 ,007407407 185 3 42 25 6 331 625 .005405405 136 184 96 2 515 456 .007352941 186 3 45 96 6 434 856 .005376344 137 187 69 2 571 353 .007299270 187 3 49 69 6 539 203 .005347594 138 190 44 2 628 072 ,007246377 188 35341 6 644 672 .005319149 139 193 21 2 685 619 .007 194 '45 189 3 57 21 6 751 239 . 00529 H '05 140 196 00 2 744 000 .007142857 190 3 6100 6 859 000 .005263158 141 198 81 2 803 221 .007092199 191 3 64 81 6 967 871 .005235602 142 2 0164 2 863 288 .007042254 192 3 68*4 7 077 888 .005208333 113 2 04 49 2 924 207 .006993007 193 3 72 49 7189 057 .005181347 144 2 07 36 2 985 984 .006914144 194 3 76 36 7 301 384 .005154639 145 210 25 3 048 625 .006898552 195 380 25 7 414 875 ,005128205 146 21316 6 112 136 .006819315 196 3 84 16 7 529 536 .005102041 147 2 16 09 3 176 523 .006802721 197 388 09 7 645 373 .005076142 148 21904 3 241 792 .006756757 108 3 92 01 7 762 392 .005050505 149 2 22 01 3 307 949 .006711409 199 3 96 01 7 880 599 60OOOOO .005025126 150 225 00 3 375 000 • .006666667 200 400 00 .005000000 USEFUL TABIDS. I 9 7 SQUARES, CUBES AND RECIPROCALS— Continued. Hos, Squares. Cubes. Reciprocals. Kos. Squares. Cubes. Reciprocals. 201 4 04 01 8 120 601 .004975124 251 6 30 01 15 813 251 .003934061 202 4 08 04 8 242 408 .004950495 252 635 04 16 003 008 .003968254 203 4 12 09 8 365 427 .034926108 253 6 40 09 16 194 277 .003952569 204 4 16 16 8 489 661 .004901961 254 6 45 16 16 387 064 .003937008 205 4 20 25 8 615 125 .004878049 255 6 50 25 16 581375 .003921569 206 • 4 24 36 8 741 816 .004854369 256 6 55 36 16 777 216 .003906250 207 4 28 49 8 869 743 .004830918 257 6 60 49 16 974 593 .003891051 208 4 32 64 8 998 912 .004807692 258 6 65 64 17173 512 .003875969 209 4 36 81 9 129 329 .004784689 259 6 70 81 17 373 979 .003861004 210 4 4100 9 261 000 .001761905 260 6 76 00 17 576 000 .003846154 211 4 45 21 9 393 931 .004739336 261 6 8121 17 779 581 .003831418 212 4 49 44 9 528 128 .0J4716981 262 6 86 44 17 984 728 .003816794 213 4 53 69 9 663 597 .004694836 263 6 9169 18 191 447 .003802281 214 4 57 96 9 800 344 .004672897 264 6 96 96 18 399 744 .003787879 215 4 62 25 9 938 375 .004651163 265 7 02 25 18 609 625 .003773585 216 4 66 56 10 077 696 .004629630 266 7 07 56 18 821 096 .003759398 217 4 70 89 10 218 313 .004608295 267 7 12 89 19 034 163 .003745318 218 4 75 24 10 360 232 .0045*7156 268 718 24 19 248 832 .003731343 2! 9 4 79 61 10 503 459 .004566210 269 7 23 61 19 465 109 .003717472 220 4 84 00 10 648 000 .004545155 270 7 29 00 19 683 000 .003703704 221 4 88 41 10 793 861 .004524887 271 7 34 41 19 902 511 .003690037 222 4 92 84 10 941 048 .004504505 272 7 39 84 20 123 648 .003676471 223 4 97 29 11089567 .004484305 273 7 45 29 20 346 417 .003663004 224* 5 0176 11239 424 .004464286 274 7 50 76 20 570 824 .003649635 225 506 25 11 390 625 -.004444444 275 7 56 25 20 796 875 .003366364 226 510 76 11 543 176 .004424779 276 7 6176 21 024 576 .003623188 227 515 29 11697 083 .001405286 277 7 67 29 21 253 933 .003610108 228 519 84 11 852 352 .004-385965 278 7 72 84 21 484 952 .003597122 229 52441 12 0)8 989 .004366812 279 7 78 41 21 717 639 .003584229 230 5 29 01) 12167 000 .001347826 280 7 84 00 21 952 000 003571429 231 6 33 61 12 326 391 .004329004 281 7 89 61 . 22 188 041 .U03558719 232 5?8 24 12 487 163 .004310:345 232 7 95 24 22 425 768 .003546099 233 5 42 89 12 649 337 .0)4291845 283 8 00 89 22 665 187 .003533569 234 5 47 56 12 812 904 .00427.3504 284 806 56 22 906 304 .003521127 235 .5 52 25 12 977 875 .004255319 285 812 25 23 149 125 .003508772 236 5 56 96 13 144 256 .004237288 286 817 96 23 393 656 .003496503 237 5 6169 13 312 053 .004219409 287 8 23 69 23 639 903 .003484321 238 5 66 44 13 481 272 .004-01681 288 829 44 23 887 872 .003472222 239 5 7121 13 651919 .004184100 289 8 35 21 24 137 569 .003460208 240 5 76 00 13 824 000 .004166667 290 8 4100 24 389 000 .003448276 241 5 80 81 13 997521 .004149378 291 8 46 81 24 642 171 .003436426 242 5 85 64 14172 488 .004132231 292 8 52 64 24 897 088 .003424658 243 5 90 49 14 348 907 .004115226 293 8 58 49 25 153 757 .003412969 244 5 95 86 14 526 784 .004098361 294 8 64 36 25 412 184 ,003401861 245 6 00 25 14 706 125 .004081633 295 8 70 25 25672 375 .003389831 246 6 05 16 14 886 936 .004065041 296 8 7616 25 934 336 .003378378 247 6 10 09 15 069 223 .004048583 297 8 82 09 26 19S 073 .003367003 218 615 04 15 252 992 .004032258 298 8 88 04 26463 592 .003355705 249 6 20 01 15 438 249 .004019064 299 8 94 01 26 730 899 .003344482 250 6 25 00 15 625 000 .004000000 300 900 00 27 000 000 .003333333 198 USKFUIv TABLES. SQUARES, CUBES AND RECIPROCALS— Continued. flos. Squares Cubes. Reciprocals. J Nos. Squares. Cubes. Reciprocals. 801 9 06 01 27 270 901 .003322259 1 351 12 32 01 43 243 551 .002849003 802 912 04 27 543 608 .003311258 352 12 39 04 43 614 208 .002840909 803 918 09 27 818 127 .003300330 353 12 46 09 43 986 977 .002832861 304 92416 28 094 464 .003289474 354 12 53 16 44 361864 .002824859 305 93025 28372 625 .008278689 355 126025 44 738 875 .002816901 306 03*36 28652616 .003267974 356 12 6736 45118016 .002808989 307 9 42 49 28934443 .003257329 357 12 74 49 45 499 293 .002801120 303 9 48 64 29 218 112 .003246753 358 12 8164 45 882 712 .002793296 309 9 54 81 29 503 629 .003236246 359 12 88 81 46 268 279 .002785515 310 Q6100 29 791000 .003225806 860 12 96 00 46 656000 .002777778 311 96721 30080231 .003215434 361 1303 21 47 045 881 .002770083 312 97344 30 371 328 .003205128 362 13 10 44 47 437 928 .002762431 313 9 79 69 30 664 297 .0-3194888 363 13 17 69 47 832 147 .002754821 314 9 85 96 30 959 144 .003184713 364 13 24 96 48 228 544 .002747253 315 9 9225 31255 875 .003174603 365 13 3225 48 627125 .002739726 316 9 98 56 31554 496 .003164557 366 133956 49 027896 .002782240 317 10 04 89 31 855 013 .003154574 367 13 46 89 49 430 863 .002724796 318 101124 32 157 432 .003144654 368 13 54 24 49 836 032 .002717891 319 101761 32461759 .003134796 369 13 61 61 50 243 409 .002710027 320 1024 00 32 768000 .003125000 370 13 69 00 60 653 000 .002702703 821 10 3041 83 076 161 .003115265 371 13 76 41 61064 811 .002695418 1036 84 33 386 248 .003105590 372 13 83 84 61 478 848 ,002688172 323 10 43 29 33 698 267 .003095975 373 13 9129 51 895 117 .002680965 324 10 49 76 34 012 224 .003086420 374 13 98 76 62 313 624 .002673797 325 1056 25 34 328125 .003076923 375. 1406 25 62 734375 .002666667 326 106276 34 645976 .003067485 376 1413 76 53 157 376 .002659574 327 10 69 29 34 965 783 .003058104 377 14 2129 53 582 633 .002652520 10 75 84 35 287 552 .003048780 378 14 28 84 54 010 152 .002645503 329 10 82 41 35 611 289 .003039514 379 14 36 41 54 439 939 .002638522 330 10 89 00 35 937000 .003030303 380 14 44 00 64 872 000 .002631679 331 1095 61 36 264 691 .003021148 381 14 51 61 65 306 341 .002624672 332 1102 24 36 594 368 .003012048 382 14 59 24 55 742 968 .002617801 11 08 89 36 926 037 .003003003 383 14 66 89 66 181 887 .002610966 m 1115 56 37 259 704 .002994012 384 14 74 56 56 623 104 .002604167 335 112225 37 595 375 .002985075 385 14 82 25 67066 625 .002597403 336 1128 96 37 933056 .002976190 386 14 89 96 67 512 456 .002590674 237 1135 69 38 272 753 .002967359 387 14 97 69 67 960 603 .002583979 83S 1142 44 38 614 472 .002958580 388 15 05 44 58 411 072 .002-577320 .'(39 1149 21 38 958 219 .002949853 389 15 13 21 68 863 869 .002570694 3-10 1156 00 39 304 000 .002941176 390 15 2100 69 319 000 .002564103 341 11 62 81 39 651 821 .002932551 391 15 28 81 59 776 471 .002557645 11 69 64 40 001 688 .002923977 392 15 36 64 60 236 288 .002551020 343 1176 49 40 353 607 .0029 5452 303 15 44 49 60 698 457 .002544529 344 11 83 36 40 707 584 .002906977 394 15 52 36 61162 984 .002538071 345 1199 25 41063 625 .002898551 395 1560 25 61629 875 .002531646 3<6 1197 16 41 421 736 .002890173 396 15 6816 62 099 136 .002525253 347 12 04 09 41 781923 ,002881844 397 15 76 09 62 570 773 .002518892 348 121104 42144192 ,0028' 7 356i 398 15 84 04 63 044 792 .002512563 340 12 18 01 42 508 549 .002865330 309 15 92 01 63 521 199 .002.506265 350 12 25 00 42 875 000 .002857143 400 16 00 00 64 000 000 .002500000 USEFUL TABIDS. 199 SQUARES, CUBES AND RECIPROCALS— Continued. Nos. Squares. Cubes. Reciprocals. flos. Squares. Cubes. Reciprocals. 401 402 403 404 405 16 03 01 16 16 04 16 24 09 16 32 18 1640 25 61 481 201 64 964 808 65 450 827 65 939 264 66 430 125 .002493766 .002487562 .002481390 .002475248 .002469136 451 452 453 454 455 20 3101 20 43 04 20 52 09 20 6116 20 70 25 91 733 851 92 345 408 92 959 677 93 576 664 94 196 375 .002217295 .002212389 .002207506 .002202643 .002197802 406 407 408 409 410 1648 36 16 56 49 16 64 64 1672 81 168100 66 923 416 67 419 143 67 917 312 68 417 929 68 921000 .002463054 .002457002 .002450980 .002444988 .002439024 456 457 458 459 460 20 79 36 20 88 49 20 97 64 21 06 81 21 16 00 94 818 816 95 443 993 96 071 912 96 702 579 97 336 000 .002192982 .002188184 .002183406 .002178649 .002173913 411 412 413 414 415 16 89 21 16 97 44 17 05 69 17 13 96 17 22 25 69426 531 69 931 528 70444 997 70 957 944 71473 375 .002433090 .002427184 .002421308 .002415459 .002489639 461 462 463 464 465 2125 21 2134 44 21 43 69 21 52 96 2162 25 97 972181 98 611 128 99 252 847 99 897 344 100544 625 .002169197 .002164502 .002159827 .002155172 .002150538 41G 417 418 419 420 17 30 56 17 38 89 17 47 24 17 55 61 17 64 00 71 991 296 72 51! 713 73 034 632 73560 059 74088 000 .002403846 .002398082 .002392344 .002386635 .002380952 466 467 468 469 470 217156 218089 21 90 24 21 99 61 22 0900 101 194 696 101847563 102 503 232 103 161 709 103 823000 .002145928 .U02141328 .002136752 .002132196 .002127660 421 422 423 424 425 17 72 41 17 8084 17 89 29 17 97 76 18 0625 74 618 461 75 151 448 75 686 967 76 225 024 76 765 625 .002375297 .002369668 .002364066 .002358491 .002352941 471 472 473 474 475 2218 41 22 27 84 22 37 29 22 46 76 22 56 25 104 487 111 105154 048 105 823 817 106 496424 107 171 875 .002123142 .002118644 .002114165 .002109705 .002105263 426 427 428 429 430 1.8 14 76 18 23 29 18 3184 18 40 41 18 49 00 77 308776 77 854 483 78 402 752 78 953589 79 507 000 .002347418 .002341920 .002336449 .002331002 .002325581 476 477 478 479 480 22 6576 22 75 29 2284 84 22 94 41 230400 107 850176 108 531333 109 215 352 109902239 110692 000 .002100840 .002096436 .002092050 .002087683 .002083383 431 432 43} 434 435 18 57 61 18 63 21 18 74 89 18 83 56 18 92 25 80 062 991 80 621 568 81 182 737 81 746 504 82 312 875 .002320186 .002314815 .002309469 .002304147 .002298851 481 482 483 484 485 2313 61 2328 24 2332 89 2342 56 236225 111281611 111 980 168 112 678587 113 379 904 114 084 125 .002079002 .002074689 .002070393 .002066116 .002061856 436 437 438 439 4)0 19 00 96 19 09 69 19 18 44 19 27 21 19 36 00 82 881856 83453 453 81027 672 84 604 519 85184 000 .002293578 .002288330 .002283105 .002277904 .002272727 486 487 488 489 490 23 6196 23 7169 23 8144 23 91 21 24 0100 114 791 256 115 501 303 116 214 272 116 930169 117 649 000 .002057613 .002053388 .002049180 .002044990 .002040816 441 442 443 444 445 19 44 81 19 53 61 19 62 49 19 71 36 19 80 25 85 766 121 86 350 888 86 938 307 87528 384 88121125 .002267574 .002262443 .002257336 .002252252 .002247191 491 492 493 494 495 211081 24 20 64 24 30 49 24 40 36 215025 118870771 119 095 488 119 823 157 120 553 784 121287375 .002036660 .0020*2520 .002028398 .002024291 ,002020202 446 447 448 449 450 19 8916 19 98 09 20 07 01 20 16 01 20 23 00 88716 536 89 314 623 89 915 392 90 518849 91125 000 .00224215Z .0;)2237136 .002232143 ,0022271m .002222222 496 497 498 499 500 24 60 16 24 70 09 24 80 04 24 90 01 25 00 00 122 023936 122763 473 123 505 992 124 251 499 125 000 000 .002016129 .002012072 .002008032 .002004008 .002000000 USEffUI, TABLES. TEIttPEKATUKES, CENTIGRADE AND FAHRENHEIT. c. F. c. F. C. F. C. F. C. F. C. F. C. F. -40 -40. 26 78.8 92 197.6 158 316.4 224 485.2 2&0 554 950 1742 -39 -38.2 27 80.6 93 199.4 159 818. 2 225 437. .300 572 960 1760 -38 -36.4 28 82.4 94 201.2 160 320. 226 438.8 310 590 970 1778 -37 —34 6 29 84.2 95 203. 161 821.8 227 440.6 320 608 980 1796 -36 —32.8 30 86. 96 204.8 162 323.6 228 442.4 W 626 990 1814 -35 -31. 31 87.8 97 206. a 163 825.4 229 444.2 H r ~ 644 1000 1832 -34 —29.2 32 89.6 98 208.4 164 327.2 230 446. f-.",0 662 1010 1850 -33 —27.4 33 91.4 99 210.2 165 329. 231 447.8 ,-r 680 1020 1868 -32 -25.6 34 93.2 100 212. 166 380.8 232 449.6 370 698 1030 1886 -31 -23.8 35 95. 101 213.8 167 332.6 233 451.4 .380 716 1040 1904 -30 -22. 36 96.8 102 215.6 168 334.4 234 453.2 ■:A 734 1050 1922 -29 -20.2 37 98.6 103 217.4 169 336.2 235 455. 400 752 1060 1940 -28 -18.4 33 100.4 104 219.2 170 338. 236 456.8 4!0 770 1070 1958 -27 -16.6 39 102.2 105 221. 171 339.8 237 458.6 420 788 1080 1976 -26 -14.8 40 104. 106 222.8 172 341.6 238 460.4 430 806 1090 1994 -25 -13. 41 105.8 107 224. Q 173 343.4 239 462.2 440 824 1100 2012 -24 -11.2 42 107.6 108 226.4 174 345.2 240 464. 450 842 1110 2030 -28 - 9.4 43 109.4 109 228.2 175 347. 241 465.8 460 860 1120 2048 -22 -7.6 44 111.2 110 230. 176 348.8 242 487.6 470 878 1130 2066 -21 — 5.8 45 118. 111 231.8 177 350.6 243 469.4 480 896 1140 2084 -20 - 4. -,, 114.8 112 233 6 178 352.4 244 471.2 ;.:-■•:< 914 1150 2102 -19 - 2.2 4? 116.6 113 235.4 179 354.2 245 478. 500 932 1160 2120 -18 - 0.4 48 118.4 114 237.2 180 856. 246 474.8 510 950 il70 2138 -17 + 1.4 49 120.2 115 239. 181 357.8 247 476.6 55.0 968 1180 2156 -18 3.2 50 122. 116 240.8 182 359.6 248 478.4 ooC 986 1190 2174 -15 5. 51 123.8 117 242.6 183 361.4 249 480.2 "■:■-;: 1004 1200 2192 -14 6.8 5S 125.6 118 244.4 184 363.2 250 482. : V. 1022 1210 2210 -13 8.6 53 127.4 119 246.2 185 365. 251 483.8 560 1040 1220 2228 -12 10.4 54 129.2 120 248. 186 366.8 252 485.6 c/( 1058 1230 2246 -11 12.2 55 131. 121 249.8 187 368.6 253 487.4 m. 1076 1240 2264 -10 14. 56 132.8 122 251.8 188 370.4 254 489.2 590 1094 1250 2282 - 9 15.8 57 134.6 123 253.4 189 372.2 255 49r. 600 1112 1260 2300 - 8 17.6 58 136.4 124 255.2 190 374. 256 492.8 '/,i 1130 1270 2318 - 7 19.4 59 138.2 126 257. 191 375.8 257 494.6 620 1148 1280 2336 - 6 21.2 60 140. 126 258.8 192 377.6 258 496.4 ..: 1166 1290 2354 - 5 23. 61 141.8 127 260.6 193 379.4 259 498,2 - 1184 1300 2372 - 4 24.8 62 143.6 128 262.4 194 381.2 260 500. 650 1202 1310 2390 - 3 26.6 63 145.4 129 264.2 195 383. 261 501.8 660 1220 1320 2408 - 2 28.4 64 147.2 130 266. 196 384.8 262 303.6 670 123# 1330 2426 - 1 80.2 65 149. 131 267.8 197 386.6 263 505.4 1680 1256 1340 2444 32. 66 150.8 132 269.6 198 388.4 264 507.2 6v30 1274 135C 2462 f 1 33.8 67 152.6 133 271.4 199 890.2 265 509. \ 1292 1360 2480 2 35.6 68 154.4 134 273.2 200 392. 266 510.8 710 1810 1870 2498 8 37.4 69 156.2 135 275. 201 393.8 267 512.6 72011828 138C 2516 4 39.2 70 158. 136 276.8 202 395.6 268 514.4 780 1346 1390 2534 5 41. 71 159.8 137 278.6 203 397.4 269 616.2 74011364 1400 2552 6 42.8 72 161.6 138 280.4 204 399.2 270 518. 750 1382 1410 2570 7 44.6 n 163.4 139 282.2 205 401. 271 519.8 76C 1400 1420 2588 8 46.4 74 165.2 140 284. 206 402.8 272 521.6 770 1418 1430 2606 9 48.2 75 167. 141 285.8 207 404.6 273 274 523.4 78C 1436 1440 2624 10 50. 76 168.8 142 287.6 208 406.4 525.2 7&0 1454 1450 2642 11 5T.8 77 170.6 143 289.4 209 408.2 225 527. 800 1472 1460 2660 12 53.6 78 172.4 144 291.2 210 410. 276 528.8 810 1490 1470 2673 13 55.4 79 174.2 145 293. 211 411.8 277 530.6 820 1508 1480 269(r 14 57.2 80 176. 146 294.8 212 413.6 278 532.4 830 1526 1490 2714 £ 59. 81 177.8 147 296.6 213 415.4 279 534.2 610 1544 1500 2732 16 60.8 'A 179.6 148 298.4 214 417.2 280 536. ,<-,- 1562 1510 2750 S 62.6 83 181.4 149 300.2 215. 419. 281 537.8 860 1580 1520 1530 2768 64.4 84 183.2 150 302. 216 420.8 282 539.6 870 1598 2786 19 66.2 85 185.- 151 303.8 217 422,6 283 541.4 880 1616 1540 2804 20 68. 86 186.8 152 305.6 218 424.4 284 543.2 890 1634 1550 2822 J21 69.8 87 188.6 153 307.4 219 426.2 285 545. 900 1652 1600 2912 22 71.6 88 190.4 154 309.2 220 428. 286 546.8 910 1670 1650 3002 23 73.4 89 192.2 155 311. 221 429.8 287 548.6 920 1688 1700 3092 24 75.2 90 194. 156 312.8 222 431.6 288 550.4 930 1706 1750 3182 25 77. 91 195.8 157 314.6 223 433.4 289 552.2 940 1724 1800 8272 USEFUL TABLES. 1 E3 IPER ATI LIRE S, FAHRENHEIT AND CENTIGRAUE. F. C. F. 26 C. F 92 C. 33.3 F 158 C. 70. F. 224 c. F. C. F. C. -40 -40. -3.3 106.7 290 143.3 360 182.2 —39 -39.4 27 - 2.8 93 33.9 159 70.6 225 107.2 291 143.9 370 187.8 -38 -38.9 28 — 2 2 94 34.4 100 71.1 226 107.8 202 144.4 380 193.3 -37 -38.3 29 — 1.7 95 35. 161 71.7 227 108.3 im 145. 890 198.9 -36 -37.8 30 - 1.1 96 35.6 162 72.2 228 108.9 294 145.6 400 204.4 -35 -37.2 31 - 0.6 97 36.1 163 72.8 229 109.4 295 146.1 410 210. -34 -36.7 32 0. 98 36.7 164 73.3 230 110. 220 146.7 420 215.6 -33 -36.1 33 -f 0.6 99 37.2 165 73.9 23! 110.6 297 147.2 480 221.1 -32 —35.6 34 1.1 100 37.8 166 74.4 232 111.1 228 147.8 410 226.7 -31 -35, 35 1.7 101 .38.3 167 75 111.7 299 148.3 4.50 232 2 -30 —34.4 36 2.2 102 38.9 168 75.6 234 112.2 300 148.9 460 237.8 —29 -33.9 87 2.8 103 "39.4 169 76.1 112.8 301 149 4 470 243.3 —28 -33.3 38 3.3 104 40. 170 76.7 236 113.3 302 150. 480 248 9 -27 -32.8 39 3.9 105 40.6 171 77.2 237 113.9 825' 150.6 490 254.4 —26 -32.2 40 4.4 106 41.1 572 77 8 2-8 114.4 301 151.1 500 260. —25 -31.7 41 5. 107 41.7 173 78.3 239 115. 305 151.7 510 265.6 —24 -31.1 42 5.6 108 42.2 174 78.9 24(. 115.6 220 152.2 520 271.1 -23 -30.6 43 6.1 109 42.8 175 79.4 211 116.1 So; 152.8 5.30 276.7 -22 —30. 44 6.7 110 43.3 176 80. 242 116.7 -,,8 153.3 540 282.2 -21 —29.4 45 7.2 111 43.9 177 80.6 243 117.2 309 153.9 550 287.8 -20 -28.9 46. 7.8 112 44 4 178 81.1 244 117.8 310 154.4 560 293.3 -19 -28.3 47 8.3 113 45. 179 81.7 245 118.3 311 155. 570 298.9 -18 -27.8 48 8.9 114 45.6 ISO 82.2 246 118.9 312 155.6 580 304.4 -17 —27.2 49 9.4 115 46.1 181 82.8 247 119.4 313 156.1 590 310. -16 —26.7 50 10. 116 46.7 182 83.3 2J8 120. 314 156.7 600 315.6 -15 -26.1 51 10.6 117 47.2 183 83.9 249 120.6 315 157.2 61.0 321.1 -14 -25.6 52 11.1 118 47.8 lti4 84.4 s,<, 121.1 316 157.8 620 326.7 —13 -25. 53 11.7 119 48.3 185 85. 251 121.7 317 158.3 ©so 332.2 -12 —24.4 54 12.2 120 48.9 186 85.6 2 re 122.2 ole 158.9 640 337.8 —11 -23.9 55 12.8 121 49.4 187 86.1 253 122.8 319 159.4 650 343.3 —10 -23.3 58 13.3 122 50. is> 86.7 254 123.3 J 160. 660 348.9 - 9 -22.8 57 13.9 123 50.6 189 87.2 255 123.9 821 160.6 670 354.4 - 8 —22.2 58 14.4 124 51.1 190 87.8 251, 124.4 322 161.1 360. — 7 -21.7 59 15. 125 51.7 191 88.3 257 125. 323 161.7 690 365.6 — 6 -21.1 60 15.6 126 52.2 192 88.9 25'- 125.6 324 162.2 700 371.1 — 5 -20.6 61 16.1 127 52.8 19? 89.4 259 126.1 ■•- 162.8 710 376.7 - 4' -20. 62 16.7 128 53.3 194 90. 261 126.7 -. 163.3 720 382.2 - 3 —10.4 C3 17.2 129 53.9 195 90.6 261 127.2 ■ - 163.9 730 387.8 - 2 -18.9 64 17.8 130 54.4 196 91.1 262 127.8 .- :■ 164.4 740 393.3 - 1 —18 3 65 18.3 131 55. 197 91.7 263 128.3 829 165. 750 398.9 -17.8 66 18.9 132 55.6 \9r 92.2 264 128.9 330 165.6 760 404.4 + 1 —17.2 67 19.4 133 56.1 199 92.8 265 129.4 331 166.1 770 410. 2 -16.7 68 20. 134 56.7 20!" 93.3 266 130. - - 166.7 780 415.6 3 -16.1 63 20.6 135 57.2 201 93.9 207 130.6 ;>: 167.2 790 421.1 4 —15.6 70 21.1 136 57 8 202 94. 4 .' 131.1 334 167.8 SOO 426.7 5 -15. 71 21.7 137 58.3 203 95. 269 131.7 335 168.3 810 432.2 6 —14.4 72 22.2 138 58.9 204 95.6 270 132.2 336 168.9 820 437.8 7 -13.9 73 22.8 139 59.4 205 96.1 271 132.8 337 169.4 830 443.3 8 —13.3 74 23.3 140 60. 206 96.7 272 133.3 338 170. 840 448.9 9 —12.8 75 23.9 141 60.6 207 97.2 273 133.9 222; 170.6 8.50 454.4 10 -12.2 76 24.4 142 61.1 208 97.8 274 134.4 340 171.1 860 460. 11 -11.7 77 25. 143 61.7 209 98.3 135. 341 171.7 870 465.6 12 —11.1 78 25.6 144 62.2 210 98.9 270 135.6 342 172.2 880 471.1 13 -10.6 79 26.1 145 62.8 211 99 4 136.1 : -, 172.8 890 476.7 14 -10. 80 26.7 146 63.3 212 100. 136.7 344 173.3 900 482.2 15 — 9.4 81 27.2 147 63.9 213 100.0 279 137.2 345 173.9 910 487.8 16 — 8.9 82 27.8 148 64.4 214 101.1 137.8 346 174.4 920 493.3 17 — 8.3 83 28.3 149 65. 215 101.7 138.3 347 175. 930 498.9 18 — 7.8 84 28.9 150 65.6 216 102.2 138.9 348 175.6 940 504.4 19 — 7.2 85 29.4 151 66.1 217 102.8 222 139.4 349 176.1 950 510; 20 — 6.7 86 30. 152 66.7 103.3 284 140. 350 176.7 515.6 21 — 6.1 87 30.6 153 67.2 219 103.9 285 140.6 351 177.2 970 521.1 22 - 5.6 88 31.1 154 67.8 104.4 286 141.1 177.8 980 526.7 23 — 5. 89 31.7 155 68.3 221 105. 141.7 353 178.3 990 532.2 24 - 4.4 90 32.2 156 68.9 105.6 142.2 354 178.9 1000 537.8 25 t- 3.9 91 32.8 157 69.4 106.1 142.8 355 179.4 1010 543.3 USEFUL TABLES. DECIMALS OF A. FOOT FOR EACH & OF AN INCH. Inch. o" 1" 2" 3" 4" 5" .0833 .1667 2500 3333 4167 i .0013 0026 .0039 .0052 .0848 .0859 .0872 .0885 .1680 .1693 .1708 • 1719 .2513 .2526 .2539 .2552 .3346 .3359 .3372 .3385 .4180 .4193 .4206 .4219 'A i i 0085 .0078 .0091 .0104, .0898 .0911 .0924 .0937 .1732 .1745 .1758 .1771 .2565 .2578 .2591 .2604 .3398 .3411 .3424 .3437 .4232 .4245 .4258 .4271 A A 8 .0117 .0130 .0143 .0156 .0951 .0984 .0977 .0990 .1784 .1797 1810 .1823 .2617 .2630 .2643 .2656 3451 .3464 .3477 .3490 .4284 .4297 .4310 .4323 .0169 .0182 0195 .0208 .1003 .1016 .1029 .1042 .1836 .1849 .1862 .1875 .2669 .2682 .2695 .2708 .3503 .3516 .3529 .3542 .4336 .4349 .4362 .4375 if .0221 .0234 .0247 .0260 .1055 .1038 .1081 .1094 .1888 .1901 .1914 .1927 .2721 .2734 ,2747 .2760 .3555 .3568 .3581 .3594 .4388 .4401 .4414 .4427 If 1 .0273 .0286 .0299 0312 .1107 .1120 .1133 .1146 .1940 .1953 .1966 .1979 .2773 .2786 .2799 .2812 .3607 .3620 .3633 .3646 .4440 .4453 .4466 .4479 11 1 .0326 .0339 0352 .0365 .1159 .1172 .1185 .1198 .1992 .2005 2018 .2031 .2826 .2839 .2852 .2865 .3659 3672 3685 .3698 .4492 .4505 .4518 .4531 * .0378 0391 .0404 .0417 .1211 .1224 .1237 .1250 .2044 •2057 .2070 .2083 .2878 .2891 .2904 .2917 .3711 .3724 .3737 .3750 .4544 .4557 .4570 .4583 USEFUL TABIDS. 203 DECIMALS OP A FOOT FOR EACH ^ OF AN INCH Inch. *6" 7" 8' P-" 10" U" 5000 5833 .6667 7500 .8333 9167 2 cubic eleven hundred feet. feet per minute. Heads in Feet. Horse Power in Feet. Horse Power. Heads in Feet. Horsepower. in Feet. Horse Power. 1 .0024147 320 .772704 1 .0016098 320 .515136 20 .0482294 330 .796851 20 .032196 330 .531234 30 .072441 340 .820998 30 .048294 340 .547332 40 .090588 350 .845145 40 .064392 350 .563430 50 .120735 360 .869292 50 .080490 360 .579528 .144S82 370 .898439 60 .096588 370 .595626 70 .169029 380 .917586 70 .112686 380 .611724 SO .193176 390 .941733 80 .128784 390 .627822 90 .217323 400 .965S80 90 .144892 400 .643920 100 .241470 410 .990027 100 .160980 410 .660018 110 .265617 420 1.014174 110 .177078 420 .676116 120 .289764 430 1.038321 120 .193173 430 .692214 130 .313911 440 1.062468 130 .209274 440 .708312 140 .338058 450 1.0S6615 140 .225372 450 .724410 150 .362205 460 1.110762 150 .241470 460 .740503 160 .386352 470 1.134909 160 .257568 470 .756606 170 .410499 480 1.159056 170 .273666 480 .772704 180 .434646 490 1.183206 180 .289764 490 .788802 190 .458793 500 1.207350 190 .305862 500 .804900 200 .482940 520 1.255644 200 .321960 520 .837096 210 .507087 540 1.303938 210 .338058 540 .869292 220 .531234 560 1.352232 220 .354156 560 .90148? 230 .555381 580 1.400526 230 .370254 580 .933684 240 .579528 600 1.44«820 240 .386352 600 .965880 250 .603675 650 1.569555 250 .402450 650 1.046370 260 .627822 700 1.690290 260 .418548 700 1.126860 270 .651969 750 1.811025 270 .434646 750 1.207350 280 .676116 800 1.931760 280 .450744 800 1.287840 290 .700263 900 2.173230 290 .466842 900 1.448820 300 .724410 1000 2.414700 SCO .482940 1000 1.609800 310 .748557 1100 2.656170 310 .499038 1100 1.770780 WHEN THE EXACT HEAD IS FOUND IN ABOVE TABLE. Example. — Have 100 foot head and 50 inches of water. How many Horse- Power? By reference to above table the Horse Power of 1 inch under 100 ft. head is .241470. This amount multiplied by the number of inches. 50, will give 12.07 Horse Power. WHEN EXACT HEAD IS NOT FOUND IN TABLE. Take the Horse Power of 1 inch under 1 ft. head and multiply by the num- ber of inches, and then by number of feet head. The product will be the required Horse Power. The above formula will answer for the cubic feet table, by substituting the the equivalents therein for those of miner's inches. Note. — The above tables are based upon an efficiency of 85%. 208 USKFUI. TABLES. LOSS OF HEAD IN PIPE BY FRICTION. The following tables show the loss of head by friction in each 100 feet in length of different diameters of pipe when discharging the following quantities of water per minute: INSIDE DIAMETER OF PIPE IN INCHES. 1 2 3 4 5 6 Vein Loss of Cubic Loss of Cublo Loss of Cubic Loss of Cubic Loss of Cubic Lose of Cubic feet feet head feet feet per In ppx in in in in per in feet. feet. mln. feet min. feet. min. feet. feet. min. 2.0 2.87 .65 1.185 2.62 .791 5.89 .593 10.4 .474 16.3 .395 23.5 2.2 2.80 .73 1.404 2.88 .936 0.48 .702 11.5 .561 18. .408 25.9 2.4 3.27 .79 1.639 3.14 1.093 7.07 .819 12.5 .050 19.6 .547 28.2 2.0 3.78 .86 1.891 3.40 1.26 7.05 .945 13.6 .757 21.3 .631 30.6 28 4.32 .92 2.16 3.66 1.44 8.24 1.08t 14.6 .864 22.9 .720 32.9 8.0 4.89 .99 2.44 3.92 1.62 8.83 1.22 15.7 .978 24.6 .815 35.3 S.2 5.47 1.06 2.73 4.18 1.82 9.42 1,37 16.7 1.098 26.2 .915 37.7 S.4 6.09 1.12 3.05 4.45 2.04, 10.00 1.52 17.8 1.22 27.8 1.021 40. 3.6 6.76 1.19 3.38 4.71 2.26 10.60 1.69 18.8 1.35 29.4 1.131 42.4 3.8 7.48 1.20 3.74 4.97. . 2.49. 11.20 1.87 19.9 1.49 31. 1.25 44.7 4.0 8.20 1.32 4.10 5.23 2.73 11.80 2.05 20.9 1.64 32.7 lv37 47.1 4.2 8.97 1.39 4.49 5.49 2.98 12.30 2.24 22.0 1.79 34.3 1.49 49.5 4.4 9.77 1.45 4.89 5.76 3.25 12.90 2.43 23.0 1.95 36.0 1.02 51.8 4.0 10.00 1.52 5.30 6.02 3.53 ■13.50 2.64 24.0 2.11 37.6 1.76 54.1 4.8 11.46 1.58 5.72 6.28 3:81 14.10 2.85- 25.1 2.27 39.2 1:90 56.5 6.0 12.33 1.65 6.17 6.54 4.11 14.70 3.08 26.2 2.46 40.9 2.05 58.9 6.2 13.24 1.72 0.02 6.80 4.41 15.30 3*31 27.2 2.65 42.5 2.21 61.2 6.4 14.20 1.78 7.10 7.00 4.73 15.90 3.55 28.2 2.84 44.2 2.37 63.6 6.0 16.16 1.85 7.58 7.32 5.06 10.50 3.79 29.3 3.03 45.8 2.53 65.9 6.8 10.17 1.91 8.09 7.58 5.40 17.10 4.04 30.3 3.24 47.4 2.70 68.3 6.0 17.23 8.01 7.85 5.74 17.70 4.31 31.4 3.45 49.1 2.87 70.7 7.0 22.89 2k 11.46 9.16 7.62 20.6 5.72 30.6 4.57 57.2 3.81 82.4 INSIDE DIAMETER OF PIPE IN INCHES. 7 8 9 10 11 12 Velo Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubio Loss of Cubic In ft. feet feet head feet feet feet feet in per per per per per sec. feet. feet. min. feet. min. feet. min. feet. feet. mm. 2.0 .338 32.0 .296 41.9 .264 53. .237 05.4 .210 79.2 .198 94.2 2.2 .401 35.3 .351 46.1 .312 58.3 .281 72. .255 87.1 .234 103. 2.4 .408 38.5 .410 60.2 .365 63.6 .327 78,5 .297 95.0 .273 113. 2.6 .540 41.7 .473 54.4 .420 68.9 .378 85.1 .344 103*. .315 122. 2.8 .617 449 .540 58.6 .480 74.2 79.5 .432 91.0 .392 111. .360 132. 3.0 .098 43.1 .611 62.8 .544 .488 98.2 .444 119. .407 141. 3.2 .785 61.3 .686 67'. .609 84.8 .549 105. .499 127. .457 151. 3.4 .876 54.5 .765 71.2 .680 90.1 .612 111. .557 134. .510 160. 3.0 .969 57.7 .848 75.4 .755 95.4 .679 118. .017 142. .566 169. 8.8 lfi70 60.9 .936 79.0 .831 101. .749 124. .080 150. .624 179. 4.0 1.175 C4.1 1.027 83.7 :913 106. .822 131. .747 158. .685 188. 4.2 1.28 07.3 1,122 87.9 .998 111. .897 137. .810 166. .749 198. 4.4 1.39 70.5 1.22 92,1 1.086 116. .977 144. .888 174. .815 207. 4.0 1.51 73.7 1.32 96.3 1.177 122. 1.059 150. .903 182, .883 217. 4.8 a.63 70.9 1.43 100.0 1.27 127. 1.145 167. 1.040 190. .954 226 6.0 1.76 80.2 1.54 105. 1.37 132. 1.23 163. 1.122 198. 1.028 235. 6.2 1.89 83.3 1.65 109. 1.47 138. 1.32 170. 1.20 206. 1.104 245 6.4 2.03 80.0 1.77 113. 1.57 143. 1.41 177. 1.28 214. 1.183 254. 6.0 2.17 89.8 1.89 117. 1.08 148. 1.51 183. 1.37 222. 1.26 264. 5.8 2.31 2.01 121. 1.80 154. 1.61 190. 1.46 229. 134 273. 6.0 2.4S 96^2 2.15 125. 1.92 159. 1.71 196. 1.56 237. 1.43 283. 7.0 3.20 112.0 2.S5 140. 2.52 185. 2.28 229. 2.07 277. 1.91 330. USEFUL TABLES. 209 LOSS OF HEAD IN PIPE BY FRICTION. The following tables show the loss of head by friction in each 100 feet in length of different diameters of pipe when discharging the following quantities of water per inipute: INSIDE DIAMETKR OF PIPE IN INCHES. 13 14 15 16 18 20 Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic In ft. feet feet feet feet reet feet In In feet. feet. feet. feet. mln. feet. mm. 2.0 .183 110. .169 128. .158 147. .147 167. .132 212. .119 262. 2.2 .216 J21. .200 141. .187 162. .175 184. .156 233. .140 2.4 .252 133. .234 154. .218 176. .205 201. .182 254. .164 314. 2.6 .290 144. .270 167. .252 191. .236 218. .210 275. .189 340. 2.8 .332 156. .308 179. .288 206. ,270 234. .240 297. .216 366. 8.0 .375 166. .349 192. .325 221. .306 251. .271 318. .245 393. 3.2 .422 177. .392 205. .366 235. .343 .305 339. .275 419. 3.4 .471 188. 438 218. .408 250. .383 284. .339 360. .306 445. J.6 .522 199. .485 231. .452 265. .425 301. .377 382. .339 471. 3.8 .576 210. .535 243. .499 280. .468 318. .416 403, .374 497. 4.0 .632 221. .587 256. .543 294. .513 335. .456 424. .410 523. 4.2 .691 232. .641 .598 309. .561 352. .499 445. .449 550. 4.4 .751 243. .698 282. .651 324. .611 368. .542 466. .488 576. 4.6 .815 254. .757 295. .707 339. .662 385. .588 488. .529 602. 4.8 .881 265. .818 308. .763. 353. .715 402. .636 509. .572 628. 6.0 .949 276. .881 321. .822 363. .770 419. .685 530. .617 654. 5.2 1.020 287. .947 833. .883 .828 435. .736 551. .662 680. 5.4 1.092 298. 1.014 346. .947 397. .888 452. .788 572. .710 707. 5.6 1.167 309. 1.083 359. 1.011 412. .949 169. .843 594. .758 733. 5.8 1.245 821. 1.155 372. 1078 427. 1.011 486. .899 615. .809 759.- fi.0 1.325 332. 1.229 385. 1.148 442. 1.076 502. .957 636. .861 785. 7.0 1.75 387. 1.63 449. 1.52 515. 1.43 586. 1.27 742. 1.143 916. INSIDE DIAMETER OF PIPE IN INCHES. 22 21 26 28 30 36 Vein. Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic Loss of Cubic I.OSSOf cubic heud feet feet feet feet feet PIT In in in in sec. feet. feet. mm. feet. feet. feet. mln. 2.0 .108 316 .098 377. .091 44? .084 513. .079 5S9. .0(56 848. 22 .127 348 .116 414. .108 486 .099 564. .093" 648. 2.4 .149 380 .136 452. .126 531 .116 616. .109 707. .091 1018. 2.6 .171 412 .157 490. .145 575 .134 667. .126 766. .104 1100. 2.8 .195 443 .180 528. .165 619 .153 718. .144 824. .119 1183. 3.0 .222 475 .204 565. .188 663 .174 770. .163 883. .135 1273. 3.2 .249 507 .229 603. .211 70S .195 821. .182 942. .152 1357. 3.4 .273 538 . .255 641. .235 75? .218 872. .204 1C01. .169 1442. 3.6 .308 570 .283 .261 796 .242 923. .226 1060. .188 1527. 3.8 .340 601 .312 716. .288 840 .267 974. .249 1119. .207 1612. 4.0 .373 633 .342 754. .315 885 .293 1026. .273 1178. .228 1697. 4.2 .408 665 .374 791. .345 9V!9 .320 1077. .299 1237. .249 1782. 4.4 .444 697 .407 829. .375 973 1129. .325 1296. .271 1866. 4.6 .482 728 .441 867. .407 1017 .378 1180. .353 1355. .294 1951 4.8 .521 760 792 .476 905. .440 106? .409 1231. Ml 1414. .318 2036. 5.0 .561 .513 942. .474 llOfl .440 1283. .411 1472. .312 212L 5.2 .602 823 .552 980. .510 1150 .473 1334. .441 1531. .368 2206.. 5.4 .645 855 .591 1018: .546 1194 .507 1885. .473 1590. .394 2291. 5.6 .690 887 .632 1055. .683 1?39 .542 1437. .506 1649. .421 2376. 5.8 .735 yi8 .674 1093. .622 19183 .578 1488. .540 1708. .450 2460. 6.0 .782 950 .717 1131. .662 1327 .615 1539. .574 1767. .479 2545. 7.0 1.040 J 109 .953 1319. .879 1548 .817 1796. .762 2061. .636 2858. USKFUIv TABLES. TABLE OF SHEET IRON HYDRAULIC PIPE. i © . 3- la, if f hi ~£ S-= £* -* . sfS'gp. r* s.g ^2 ££ So-3 §f££ £is 3 7 18 400 9 2 4 12 18 350 16 2* 4 12 16 525 16 3 5 20 18 325 25 3* o 20 16 500 25 4} o 20 14 675 25 5 a 28 18 296 36 4| 6 28 16 487 36 6* 6 28 14 743 36 7} 38 18 254 50 5} 7 38 16 419 50 6* 7 38 14 640 50 8} 8 50 16 367 63 7* 8 50 14 560 63 9h 8 50 12 854 63 13 y 63 16 327 80 8* !) 63 14 499 80 10£ 9 63 12 761 80 14* 10 78 16 295 100 9* so 78 14 450 100 in 10 78 12 687 100 15f 10 78 11 754 100 17* 10 78 10 900 100 19} 11 95 16 269 120 n 11 95 14 412 120 13 11 95 12 626 120 17* 11 95 11 687 120 18jf 11 95 10 820 120 ' 21 12 113 16 246 142 in 12 113 14 377 142 14 12 113 12 574 142 18} 12 113 11 630 142 19| 12 113 10 16 753 142 22| 13 132 228 170 12 13 132 14 348 170 15 13 132 12 530 170 20 13 132 11 583 170 22 13 132 10 696 170 24} 14 153 16 211 200 13 14 153 14 324 200 16 14 153 12 494 200 214 14 153 11 543 200 23* 14 153 10 648 200 *6 15 176 16 197 225 13f 15 176 14 302 225 17 15 176 12 460 225 23 15 176 11 507 225 24* 15 176 10 606 225 28 16 201 16 185 255 14* 16 201 14 283 255 17* 46 201 12 432 255 24* 16 201 11 474 255 26* i£ I 201 10 567 255. 29J || £.5 & p. If is P ill K5.TS •°.seS 18 254 16 165 320 16* 18 254 14 252 320 20* 18 254. 12 385 320 2;* 18 254 11 424 320 30 ,18 254 10 505 320 34 20 314 16 148 400 18 20 314 14 227 400 22} 20 314 12 346 400 30 20 314 11 380 400 324 20 314 10 "16 456 135" 400 4«0 36} n 380 20 22 380 14 206 480 m 22 380 12 316 480 32$ 22 380 H 347 480 35$ 22 380 10 415 480 40 24 452 14 188 570 27* 24 452 12 290 570 35* 24 452 11 318 570 39 24 452 10 379 570 43* 24 452 8 466 570 53 26 530 14 175 670 29* 26 530 12 267 670 38* 26 530 11 294 670 42 26 530 10 352 670 47 26 530 8 432 670 57* 28 615 14 102 775 31* 28 615 12 247 775 41* 28 615 11 273 775 45 28 615 10 327 775 50* 28 615 8 400 775 61* 30 706 12 231 890 44 30 706 11 254 890 48 30 706 10 304 890 54 30 706 8 375 890 65 30 706 7 425 141 890 74 83 1017 11 1300 58 m 1017 10 155 1300 67 36 1017 8 192 1300 78 36 1017 7 210 1300 88 40 1256 10 141 1600 71 40 1256 8 174 1600 86 40 1256 7 189 1600 97 40 1256 6 213 1600 108 40 1256 4 250 1600 126 4 s ? 1385 10 135 1760 74* 4->, 1385 8 165 1760 91 A?, 1385 7 180 1760 102 4", 1385 6 210 1760 114 42 1385 4 240 1760 133 49, 1385 y 270 1760 137 4'* 1385 3 300 1760 145 42 1385 tV 321 1760 177 42 1385 ■ : fi 363 . 1760 216 USEFUL TABLES. ?*i rt K3 c< o *> W N Cr N CO 00 . vS \ 2 i fO * i w o NO o rO * ■3- d CO * CO _ cO > E * >-n <^ iti CO o H •T ^0 N. cr o rl >N^ .pi S3 •V c- o o ;»c!l i ■ •* J >« s o o o o o O CV iyj -5 * rt •0 CO »0 cr o ' o 5 r: J ! J" £% «■ vS m to fO N CO cr- £ > iT^j cc s <» IS j „ o Q ^ > V N 00 rj- — N eo ^T k) VJ> K «D cr - 1 "1 ! ! ! - - — si Pi N Csf rt M cv rj w n r0 (0 *.« 1 Jr'*" r p z ^ili££^ « 2^ H so to "0 K sO 206 2.30 .8329 2.74 1.0080 3.18 1.1569 1.43 .3577 1.87 .6259 2.31 .8372 2.75 1.0116 3.19 1.1600 1.44 .3646 1.88 .6313 2.32 • 8416 2.76 1.0152 3.20 1.1632 214 USEFUL TABLES. HYPERBOLTC LOGARITHMS. No.. Log. No. Log. No. Log. No. Log. No. Log. 3.21 1.1663 3.87 1.3533 4.53 1.5107 5.19 1.6467 5.85 1.7664 3.22 1.1694 3.88 1.3558 4.54 1.5129 5.20 1.6487 5.86 1.7681 3.23 1.1725 3.89 1.3584 4.55 1.5151 5.21 1.6506 5.87 1.7699 3.24 1.1756"" 3.90 1.3610 4.56 1.5173 5.22 1.6525 5.88 1.7716 3.25 1.1787 3.91 1.3635 4.57 1.5195 5.23 1.6514 5.89 1.7733 3.26 1.1817 3.92 1.3661 4.58 1.5217 5.24 1.6563 5.90 1.7750 3.27 1.1848 3.93 1.3686 4.59 1.5239 5.25 1.6582 5.91 •1.7766 3.28 1.1878 3.94 1.3712 4.60 1.5261 5.26 1.6601 5.92 1.7783 3.29 1.1909 3.95 1.3737 4.6i 1.5282 5.27 1.6620 5.93 1.780C 3.30 1.1939 3.96 1.3762 4.62 1.5304 5.28' 1.6639 5.94 1.7817 3.31 1 1969 3.97 1.3788 4.63 1.5326 5.29 1.6658 5.95 j .7834 3.32 1.1999 3.98 1.3813 4.64 1.5347 5.30 1.6677 5.96 1.7851 3.33 1.2030 3.99 1.3838 4.65 1.5369 5.31 1.6696 5.97 1.7867 3.34 1.2060 4.00 1.3863 4.66 1.5390 5.32 1.6715 5.98 1.7884 3.35 1.2090 4.01 1.3888 4.67 1.5412 5.33 1.6734 5.99 1.7901 3.36 1.2119 4.02 1.3913 4.68 1.5433 5.34 1.6752 6.00 1.7918 8.37 1.2149 4.03 1.3938 4.69 1.5454 5.35 1.6771 6.01 1.7934 3.38 1.2179 4.01 1.3962 4.70 1.5476 5.36 1.6790 6.02 1.7951 3.39 1.2208 4.05 1.3987 4.71 1.5497 5.37 1.6808 6.03 1.7967 3.40 1.2238 4.06 1.4012 4.72 1.5518 5.38 1.6827 6.04 1.7984 3.41 1.2267 4.07 1.4036 4.73 1.5539 5.39 1.6845 6.05 1.8001 3.42 1.2296 4.08 1.4061 4.74 1.5560 5.40 1.6864 6.06 1.8017 3.43 1.2326 4.09 1.4085 4.75 1.5581 5.41 1.6882 6.07 1.8034 3.44 1 .2355 4.10 1.4110 4.76 1.5602 5.42 1.6901 6.08 1.8050 3.45 1.2384 4.11 1.4134 4.77 1.5623 5.43 1.6919 6.09 1.8066 3.46 1.2413 4.12 1.4159 4.78 1.5644 5.44 1.6938 6.10 1.8083 3.47 1.2442 4.13 1.4183 4.79 1.5665 5.45 1.6956 6.11 1.8099 3.48 1.2470 4.14 1.4207 4.80 1.5686 5.46 1.6974 6.12 1.8116 3.49 1.2499 4.15 1.4231 4.81 1.5707 5.47 1.6993 6.13 1.8132 3.50 1.2528 4.16 1.4255 4.82 1.5728 5.48 1.7011 6.14 1.8148 3.51 1.2556 4.17 1.4279 4.83 1.5748 5.49 1.7029 6.15 1.8165 3.52 1.2585 4.18 1.4303 4.84 1 .5769 5.50 1.7047 6.16 1.8181 3.53 1.2613 4.19 1.4327 4.85 1.5790 5.51 1.7066 6.17 1.8197 3.54 1.2641 4.20 1.4351 4.86 1.5810 5.52 1.7084 6.18 1.8213 3.55 1.8669 4.21 1.4375 4.87 1.5831 5.53 1.7102 6.19 1.8229 3.56 1.2698 4.22 1.4398 4.88 1.5851 5.54 1.7120 6.20 1.8245 3.57 1.2726 4.23 1 .4422 4.89 1.5872 5.55 1.7138 6.21 1.8262 3.58 1.2754 4.24 1.4446 4.90 1.5892 5.56 1.7156 6.22 J. 8278 3.59 1.2782 4.25 1.4469 4.91 1.5913 5.57 1.7174 6.23 1.8294 3.60 1.2809 4.26 1.4493 4.92 1.5933 5.58 1.7192 6.24 1.8310 3.61 1.2837 4.27 1.4516 4.93 1.5953 5.59 1.7210 6.25 1.8326 3.62 1.2865 4.28 1.4540 4.94 1.5974 5.60 1.7228 6.26 1.8342 3.63 1.2892 4.29 1.4563 4.95 1.5994 5.61 1.7246 6.27 1.8358 3.64 1.2920 4.30 1.4586 4.96 1.6014 5.62 1.7263 6.28 1.8374 3.65 1.2947 4.31 1.4609 4.97 1.6034 5.63 1.7281 6.29 1.8390 3.66 1.2975 4.32 1.4633 4.98 1.6054 5.64 1.7299 6.30 1.8405 3.67 1.3002 4.33 1 .4656 4.99 1.6074 5.65 1.7317 6.31 1.8421 3.68 1.3029 4.34 1.4679 5.00 1.6094 5.66 1.7334 6.32 1.8437 3.69 1.3056 4.35 1.4702 5.01 1.6114 5.67 1.7352 6.33 1.8453 3.70 1.3083 4.36 1.4725 5.02 1.6134 5.68 1.7370 6.34 1.8469 3.71 1.3110 4.37 1.4748 5.03 1.6154 5.69 1.7387 6.35 1.8485 3.72 1.3137 4.38 1.4770 5.04 1.6174 5.70 1.7405 6.36 1.8500 3.73 1.3164 4.39 1.4793 5.05 1.6194 5.71 1.7422 6.37 1.8516 3.74 1.3191 4.40 1.4816 5.06 1.6214 5.72 1 .7440 6.38 1.8532 3.75 1.3218 4.41 1.4839 5.07 1.6233 5.73 1.7457 6.39 1.8517 3.76 1.3244 4.42 1.4861 5.08 1.6253 5.74 1.7475 6.40 1.8563 3.77 1.3271 4.43 1.4884 5.09 1.6273 5.75 1.7492 6.41 1.8579 3.78 1.3297 4.44 1.4907 5.10 1.6292 5.76 1.7509 6.42 1.8594 3.79 1.3324 4.45 1.4929. 5.11 1.6312 5.77 1.7527 6.43 1.8610 3.80 1.3350 4.46 1.4951 5.12 1.6332 5.78 1.7544 6.44 1.8625 3.81 1.3376 4.47 1.4974 5.13 1.6351 5.79 1.7561 6.45 1.8641 3.82 1.3403 4.48 1.4996 5.14 1.6371 5.80 1.7579 6.46 1.8056 3.83 1.3429 4.49 1.5019 5.15 1 .6390 5,81 -1.7596 6.47 1.8672 3.84 1.3455 4.50 1.5041 5.16 1.6409 5.82 1.7613 6.48 1.8687 3.85 1.3481 4.51 1.5063 5.17 1.6429 5.83 1 .76% 6.49 1.8703 3.86 1.3507 4.52 1.5085 5.18 1.6448 5.84 1.7647 1 6.50 1.8718 USEFUL TABLES. 215 Volume, wensity, and Pressure of Air at Various Temperatures. (D.K.Clark.) Volume at Atinos. Pressure at Constant Pressure. Density, lbs. Volume. per Cubic Foot at Atmos. Pressure. Fahr. Cubic Feet Compara- Lbs. per Compara- tive Pres. in 1 lb. tive Vol. ' Sq. In. 11.583 .881 .086331 12.96 .881 32 12.387 .943 .080728 13.86 .943 40 12.586 .958 .079439 14.08 .958 50 12.840 .977 .077884 14.36 .977 62 13.141 1.000 .076097 14.70 1.000 70 13.342 1.015 .074950 14.92 1.015 80 13.593 1.Q34 1.054 .073565 15.21 1.034 90 13.845 .072230 15.49 1.054 100 14.096 1.073 .070942 15.77 1.073 no 14.344 1.092 .069721 16.05 1.092 120 14.592 1.111 .06^500 16.33 1.111 130 14.846 1.130 .067361 16.61 1.130 140 15.100 1.149 .066221 16.89 1.149 150 15.351 1.168 .065155 17.19 1.168 160 15.603 1.187 .064088 17.50 1.187 170 15.854 1.206 .063089 17.76 1.206 180 16.106 1.226 .062090 18.02 1.226 200 16.606 1.264 .060210 18.58 1.264 210 16.860 1.283 .059313 18.86 1.283 212 16.910 1.287 .059135 18.92 1.287 2l6 USEFUL TABLES, Volumes, mean Pressures per Stroke, Temperatures, etc.. in the Operation of Air-compression from 1 Atmosphere and 60° Fahr, (F. Richards, Am. Mack., March 30, 1893.) t- _• i t. 6 3 | 9- i CO w O s |1 < * O to ft a, jj c m o 3 p a 3 — "O £ i>'o «5-^ c 3 O O o ft § «5 ©^ o JJCQ 0)73 cd 0*> o Vrn 0)02 35 < > * 5> § H o < > a > £T s 1 S 3 4 5 6 7 1 2 3 4 5 6 7 1 1 1 60° 80 6. 442. 1552 .267 27.38 36.64 "432 1 J. 068 .9363 .95 .96 .975 71 85' 6.182 .1474 2566 28.16 37.94 447 2 1.136 .8803 .91 1.87 .1.91 80.4 90! 7.122 .1404 .248 28.89 39.18 459 3 1.204 .8305 .876 2.72 2 8 88.9 95 ! 7.462 .134 .24 29.57 40.4 472 4 1.272 .7861 .84 3.53 H 67 98 100 1 7.802' 1281 .232 30.21 41.6 485 5 1.34 .7462 .81 4.3 4 5 106 1051 8.1421 1228 2254 30.81 42.78 496 10 1 68 .5952 .69 7.62 8.27 145 110 8 483 .1178 .2189 31.39 43.91 507 15 2.02 .495 .606 10.33 11.51 178 1151 8 823' .1133 .2129 31.98 44.98 518 SO 2.36 .4237 .543 12.62 14.4 207 120, 9.163' 1091 .2073 32.54 46.04 529 25 2.7 .3703 .494 14.59 17.01 234 125 9. 503.. 1052 .2020 33.07 47.06 540 30 3!oi 3289 .4538 16.34 19.4 252 130 9.843 .1015 .1969 33.57 48.1 550 35 3.3S1 .2957 .42 17.92 21.6 281 135 10.183' 0981 .1922 34.05 49.1 560 40 3.721 .2687 393 19.32 23 66 302 140 10.5?3'.095 .1878 34.57 50.02 570 45 1.061 .2462 .37 20.57 *5.59 321 145 10.864 .0921 .1837 35.09 51. 580 MJ 4.401 .2272 .35 21.69 27.39 339 150 11.204 .0892 .1796 35.48 51.89 589 r>r> 4.741 .2109 331 22.76 29.11 357 160 11.88 .0841 .1722 36.29 53.65 607 fiO 5.081 .1968 .3144 23 . 78 30 75 375 170 12.56 0796 .1657 37.2 55.39 624 65 0.423 .1844 .301 24.75 32 32 389 180 13 24 0755 .1595 37.96 57.01 640 70 5.762 .1735 288 25 67 33.83 405 190 13.92 .0718 .154 38.68 58.57 657 ?S 6.102 .1639 .276 26.55 35.2? 420 200 14.6 .0685 .149 39.42 60.14 672 USEFUL TABLES. Mean and Terminal Pressures of Compressed AJr used Expansively for Gauge-pressares from 60 to 100 lbs. (Frank Richards, Am. Mack, April 13, 5893.) Initial Pres- 60. 70. 80. 90. 100 sure. ojb SU§ .Si 5 B . 2 Bc.3 « 1 * u S * s 3 ". *■ *3 a) 0) *3 © .5.- % O 3 £<% £<% %<% £^£ l3 Z.ZZ . 4 5" . 8095 q .III . 3 55^ 2. ♦ 5 . 8465 8 . ins . sa^ 1. SZ , 5 s . 8/86 7 .143 . 4AI A. 6 6 . 6 . 9066 6.6 6 • / 5" .434/ 1.6 . 6a5 • 9 ' 8 7 6 . !66 . 4653 1.5-4 . 6 5* .QJLCJ2 S. 7 i • i 7 5- .^807 1.4 8 , 6 j S . C}4 o5 J T^U •€. of Mean Absolute Pressures l/anows Decrees of IsotkeTmaL Expansion — » _f.r P, i«, rtv«, P», IS tf» R_ ,s 4 C 3 W» ± inel.< B, — In this Table Absolute. Pressure. o»V whick. Sticuw. ev\T"er.S M\e. C e. corveipondma Mian Absolut*. Pressure. , e. Hate of E*p* wJ »' OM -, '"•"•• Hve. /Ratto «f Hit VoWd v o\e.T , I'weW.'n^ CUo.ra.wc, U U\i Volunn* of Lw«- SVt»w, ftttS Hit point- of Cu.r.off, ifc.fU Ratio of Hie. h>Ul Vol v ft. rUt Voho.1 Volume of Cvli'i*cUv 1 3 4 1C7 ' • i 1 I 1-66 . I 4 i.ji " £ — - Lap- Wcl4ed — — - NtMl'-MAl twSi'da. ActwoJ ' O i A vucfa f TVcKnets N»iwi*m*I [>»t Fo.h — L>4 |»«.t IhcK of Screw »i l. i 12.7* .3^5 4Q 8 i 3 14 • 37^ 54 8 1 H IS • 37* S8 » 1$ 16 .3 7 5- 6X 8 — List of Sffcawv, A»r «\h«i Ware/ P.>*S . - INDEX. PAGE A ir Compressors— General Remarks 81 Air Engines 38 Air Engines, Exhaust Temperatures and Reheating 50 Air Receivers 182 Available Work at Complete Expansion, Curve of. 30 Available Work at Full Expansion, Table of. 31 Blacksmith Tools 186 Capacity of Compressors 84 Calculation of H. P. of Water, Table of 207 Circumferences and Areas of Circles 191 Column Mountings 180 Compressed Air, General Principles 3 COMPRESSORS— Combined Duplex Steam Actuated and Shaft-driven Com- pressors, Class G 105 Compound Corliss Actuated Compressors, Class J 110 Direct Acting Steam Actuated Duplex Compressors, Light Duty, Class L 119 Duplex Steam Actuated Compressors, Class A 86 Duplex Shaft-driven Compressors, Class D 95 Duplex Tandem Sectional Shaft-driven Compressors, Class E. 99 Light Duty Compressor or Vacuum Pump, Class K 117 Single Steam Compressors, Class B 91 Single Steam Actuated Compressors, Self-contained Type, Class C 93 Single Shaft-driven Compressors, Class F 102 Single Corliss Actuated Compressors, Class 1 113 Steam Actuated Vertical Compressors, Class H 108 Steam Actuated Single Air Compressors, Class M 121 Consumption of Air 40 Consumption of Air, Single Cylinder Automatic Engines 41 Consumption of Air, Compound Automatic Engines 42 Consumption of Air, Single Cylinder Corliss Engines 43 Consumption of Air, Compound Corliss Engines 44 Consumption of Air, Corliss Compound Pneumatic Motors, Table of 51 Consumption of Air for pumps 61 Consumption of Air, Rock Drills 85 Decimals of a Foot per Each Sixty-fourth of an Inch 202 Decimals of an Inch for Each Sixty-fourth 206 Difference of Level in Use of Compressed Air 35 Difference of Level in Use of Compressed Air, Table of 37 Equation of Pipes 212 Expansion of Air 45 INDEX. PAGE Fifth Roots and Fifth Powers 194 General Hints 178 Hyperbolic logarithms 213 Indicated Horse Power to Compress Air 56 Indicated Horse Power to Compress Air, Curve for 57 Loss of Pressure in Pipes ". 21 Loss of Pressure through Bends 33 Loss of Pressure through Bends, Table of 34 Loss of Head in Pipes! by Friction 208 Lubricators and Lubricants 187 Mean and Terminal Pressures of Compressed Air 217 Mean Absolute Pressures Tor Various Degrees of Isothermal Expansion, Table of 218 Mean Effective Pressures, Curve of 58 Pneumatic Governors 127 Pneumatic Hoist 52 Pneumatic Locomotive 70 Pneumatic Plant at Grass Valley 134 Pneumatic Torpedo Plant at Presidio, S. F 140 Power Transmission by Compressed Air 71 Pressure in Vertical Pipes 59 Quantity of Air Compressed per Indicated Horse Power 53 Quantity of Air Compressed per Indicated Horse Power, Curve for 54 Reheater 48 Refrigeration by Compressed Air 63 Rix Patent Hose Couplings 186 ROCK DRILLS— Rock Drills 158 Rock Drills, Rix, Table of 170 Roak Drills, Giant, Table of 171 Rock Drills, Plug and Feather 176 Sheet Iron Hydraulic Pipe, Table of 210 Squares, Cubes, and Reciprocals 195 Tripod Mountings 165 Temperatures, Centigrade, and Fahrenheit 200 Volume, Density, and Pressure of Air at Various Temperatures. 215 Volumes, Mean Pressure per Stroke, Temperatures 216 Well Casing, List of 219 Wrought Iron Pipe, List of 220 <\ \ '