yi_n_n__rL_n_ 
 
 REESE LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA 
 
 Deceived 
 Accession No. 91390. Class No. 
 
 Be sure to get the best, which 
 is fully guaranteed by us, and 
 which always has our trade mark 
 
 Established J853 
 
 Incorporated J885 
 
 CAPITAL, $1,000,000 
 
AD VKKTISEMKN TS 
 
 The National Ammonia Go. 
 
 GENERAL OFFICES: ST. LOUIS, MO. 
 
 EASTERN AND EXPORT OFFICE : 90 WILLIAM ST., NEW YORK 
 
 CM. Addres..,] " 
 MANUFACTURERS OF ABSOLUTELY PURE AND DRY 
 
 Liquid 
 
 Anhydrous 
 
 Ammonia 
 
 Aqua Ammonia 
 
 For Refrigerating and Ice Making Purposes. 
 
 Our Ammonia is entirely free from any impurities that 
 
 can detract from refrigerating- effects or impair machin- 
 ery, and those using- our products obtain best results 
 with their machines. Our prices are always as low as 
 others for goods of equivalent quality. Inquiries and 
 orders solicited. 
 
 UNEXCELLED GOODS. UNEQUALED SERVICE 
 
 Our Ammonia can be had of the Following: 
 
 NEW YORK PITTSBURGH 
 
 The De La Vergne Ref. Mach. Co. Union Storage Co., Transfer Agts. 
 
 W. M. Schwenker. 
 
 NEW ORLEANS 
 
 The National Ammonia Co., L N Brimswi* * m 
 
 1 OP .IT T) nv : n rn n * 
 
 Theo. J. Goldschmid Co. W ' Davis O11 Co - 
 
 BALTIMORE-Wm. Mitchell. T MaUinckrodt Chemical Work, 
 
 WILMINGTON Larkin & Scheffer. 
 
 Delaware Chemical Co. CHICAGO - 
 
 BUFFALO-S. J. Krull. A. Magnus' Sons' Co 
 
 BOSTON Fuller & Fuller Co ' 
 
 The Lyons & Alexander Co. MILWAUKEE- 
 
 KANSAS CITY S. J. Thomson. Baumbach, Reichel & Co. 
 ' 
 
 Herman Goepper & Co. " *J* ISMUM 
 CLEVELAND Geo. Herrmann Co. 
 
 Cleveland Brewers' Supply Co. Pacific Ammonia & Chemical Co. 
 
 DETROIT LIVERPOOL, ENG. 
 
 Michigan Ammonia Works. " Ja8 - Simpson & Co. 
 
 INDIANAPOLIS, IND. SYDNEY, N. S. W. 
 
 Indianapolis Warehouse Co. The Ammonia Co. of Australia. 
 
ADVERTISEMENTS 
 
 CROSBY 
 
 STEAM GAGE AND 
 VALVE CO. 
 
 SOLE MANUFACTURI 
 
 CROSBY STEAM ENGINE 
 
 AND 
 
 AMMONIA INDICATOR 
 
 Approved and adopted by the U. S. Govern- 
 ment. It is the standard in nearly all the great 
 Hlectric Light and Power Stations of the United 
 States. It is also the standard in the principal 
 Navies, Government Ship Yards and the most 
 eminent Technical Schools of the world. 
 
 When required it js furnished with Sar- 
 gent's Eleetrieal Attachment, by which any 
 number of diagrams from Compound Engines 
 can be taken simultaneously. 
 
 This attachment is protected by Letters 
 Patent. The public is warned against other 
 similar attachments which are infringements. 
 
 ALSO SOLE MANUFACTURERS OF 
 
 Perfect in Design. 
 Faultless in Work- 
 manship. 
 
 Crosby Improved Steam Gages, Pop Safety Valves, Water Relief Valves, 
 
 Patent Gage Testers, Safe Water Gages, Revolution Counters, 
 
 ORIGINAL Single Bell Chime Whistles and other standard 
 
 specialties used on Boilers, Engines, Pumps, etc. 
 
 MAIN OFFICE AND WORKS: BOSTON, MASS., U. S. A. 
 
 Stores: BOSTON, NEW YORK, CHICAGO and LONDON, ENG. 
 
 COILS 
 
 BENDS AND MANIFOLDS FOB 
 
 Ice and Refrigerating Machinery 
 
 AMMONIA VALVES AND FITTINGS. 
 
 Hairisburo 
 Pipe Bending Go., w. 
 
 HARRISBURG, PA. 
 
 The Harrisburg Copper Coil 
 Feed Water Heater. 
 
 CARBONIC ACID GAS AND ANHYDROUS 
 AMMONIA 
 
 RECEIVERS AND CYLINDERS 
 
INDICATING 
 
 TtiE 
 
 REFRIGERATING MACHINE 
 
 THE APPLICATION OF THE INDICATOR TO THE AMMONIA 
 
 COMPRESSOR AND STEAM ENGINE, WITH PRACTICAL 
 
 INSTRUCTIONS RELATING TO THE CONSTRUCTION 
 
 AND USE OF THE INDICATOR AND READING 
 
 AND COMPUTING INDICATOR CARDS 
 
 BY 
 
 GARDNER T. VOORHEES, S. B. 
 
 MECHANICAL ENGINEER WITH THE 
 
 QUINCY MARKET COLD STORAGE CO. 
 
 BOSTON, MASS. 
 
 CHICAGO 
 
 H. S. RICH & Co. 
 
Copyrighted 1898, by H. S. RICH & CO. 
 
 ALL RIGHTS RESERVED. 
 
 Press of 
 ICH AND REFRIGERATION, 
 
 CHICAGO. 
 
PREFACE. 
 
 Often while plotting- the adiabatic curve on 
 an indicator card taken from an ammonia com- 
 pressor, I have wished to shorten the time re- 
 quired and simplify the process. This led to 
 working- out the constants in Table No. 1. Having- 
 these constants, Table No. 2 naturally sug-g-ested 
 itself to still further simplify the work. In addi- 
 tion to this I have added such other matter as 
 seemed pertinent to a work of this character, 
 hoping- to place before the reader all necessary 
 references for one who may have to work up 
 indicator cards taken from an ammonia com- 
 pressor. If my reader appreciates the value of 
 the adiabatic curve after looking- throug-h this 
 work, and learns to use Table No. 2, I feel that 
 my aim will have hit the mark. 
 
 G. T. V. 
 
 91390 
 
CONTENTS. 
 
 PART I. 
 
 INDICATING THE AMMONIA COMPRESSOR. 
 
 Chapter I. The Elementary Indicator; a simple 
 
 description of the principles involved 7 
 Chapter II. The Value of Indicating- a Compressor 11 
 
 Chapter III. The Adiabatic Curve 19 
 
 Chapter IV. The Isothermal Curve 25 
 
 Chapter V. Discussion of the Adiabatic and Iso- 
 thermal Curves 29 
 
 Chapter VI. Finding the Horse Power of an Indi- 
 cator Card 37 
 
 Chapter VII. Actual Displacement of a Compressor 39 
 Chapter VIII. Special Faults as Shown by Cards. . . 4<i 
 Chapter IX. Wet Compressor System Indicating-. . 51 
 Chapter X. Instructions for Connecting- Indicator 
 
 to Machine.. . 57 
 
 Chapter 
 Chapter 
 
 Chapter 
 Chapter 
 Chapter 
 Chapter 
 Chapter 
 
 PART II. 
 
 INDICATING THE STEAM ENGINE. 
 
 I. The Steam Engine Indicator 59 
 
 II. How and Where to Attach the Indi- 
 cator 72 
 
 III. The Drum Motion 
 
 IV. How to Take Diagrams 
 
 V. How to Find the Power of an Engine. 
 
 VI. The Hyperbolic Curve 
 
 VII. Amsler's Polar Planimeter. . , 
 
 76 
 
 84 
 
 89 
 
 96 
 
 103 
 
 Chapter 
 Chapter 
 
 PART III. 
 
 CONSTRUCTION OF INDICATORS. 
 
 I. The Crosby Indicator 108 
 
 II. The Bachelder Adjustable Spring 
 
 Indicator.., ..116 
 
CONTENTS. V 
 
 Chapter III. Improved Robertson-Thompson Indi- 
 cator 119 
 
 Chapter IV. The Buffalo Indicator. 123 
 
 Chapter V. American Thompson. Indicator 126 
 
 Chapter VI. The Tabor Indicator 133 
 
 Chapter VII. The Improved Victor Reducing Wheel. 141 
 
 Chapter VIII. The Ideal Reducing- Wheel .144 
 
 Chapter IX. Sargent's Electrical Attachment for 
 
 Steam Engine Indicators 146 
 
 Chapter X. Armsler's Polar Planimeter 149 
 
 Chapter XI. The Lippincott Planimeter 150 
 
 Chapter XII. The Coffin Averaging Instrument 154 
 
 PART IV. 
 
 MISCELLANEOUS TABLES. 
 
 Properties of Saturated Ammonia 160-163 
 
 Table of Ammonia Gas (Super-heated Vapor) 164 
 
 Refrigerating Effect of One Cubic Foot of Ammonia 
 
 Gas 165 
 
 Number of Cubic Feet of Gas Pumped per Minute to 
 
 Ton of Refrigeration 165 
 
 Anhydrous Ammonia, Composition of 166 
 
 Testing Anhydrous Ammonia 166-167 
 
 Comparisons of Thermometer Scales 168 
 
 Mean Pressure of Diagram of Ammonia Compressor . 169 
 
 Properties of Saturated Steam , 170-172 
 
 Mean Effective Pressure of Diagram of Steam Cyl- 
 inder 173 
 
 Head of Water and Equivalent Pressure in Pounds 
 
 per Square Inch 174 
 
 Properties of Solution of Salt (Chloride of Sodium). . .175 
 
 Properties of Solution of Chloride of Calcium 175 
 
 Diameters, Areas and Circumferences of Circles. .176-178 
 Table of Piston Speeds : Feet per Minute 179 
 
INDICATING 
 
 THE 
 
 REFRIGERATING MACHINE 
 
 PART I. 
 INDICATING THE AMMONIA COMPRESSOR. 
 
 CHAPTER I. 
 
 THE ELEMENTARY INDICATOR. 
 
 For the convenience of those who are not 
 familiar with the principle of the indicator, but 
 may wish to look through this book, I will give 
 an elementary description of the principles in- 
 volved. I sincerely hope that thus I may be able 
 to bring- this work understandingly before those 
 who are interested in or own compressors, but 
 who have not had a technical education. 
 
 In Fig. Itf, shown on opposite page, let A be 
 the compressor cylinder; B the piston; C the 
 suction valve; D the discharge valve; E the 
 piston rod; F the cross-head; G G cross-head 
 guides; If a. board made fast to the cross-head; 
 /a piece of paper called an indicator card blank, 
 which is tacked to board H; /a small cylinder, 
 having piston A" and piston rod Z, compression 
 spring M; A r pencil carried by piston rod L; O O 
 pipe leading from cylinder A to cylinder J; P 
 cock that may connect cylinders A and/, or shut 
 off A from / at the same time leaving cylinder/ 
 open to the atmospheric pressure. 
 
8 INDICATING THE 
 
 Now we will suppose pencil A r to press against 
 paper /, and cross-head f^to move in the direc- 
 tion 1, 2. Evidently the pencil N will trace the 
 straight line aa^ on paper /. Now whatever 
 pressure exists in cylinder A must also be in 
 cylinder J, being transmitted through the pipe 
 O O. Suppose now the pencil N at position c 
 representing atmospheric pressure in cylinder 
 A, then allow pressure in cylinder A to gradually 
 increase, the cross-head F remaining fixed in 
 position. It is evident that this pressure will 
 move piston K, compress spring J/and trace the 
 line cb with pencil N. Then if the pressure in 
 cylinder A is reduced the piston It will return 
 to its original position by virtue of spring M. 
 Now suppose spring Mto be so constructed that 
 one pound per square inch pressure in cylinder 
 A will compress it .01 of an inch and that 100 
 pounds per square inch will compress it one inch; 
 it will be evident that every .01 of an inch of line 
 a b represents one pound per square inch press- 
 ure in cylinder A. If a b is .75 inches long, 
 then the pressure in cylinder A is seventy-five 
 pounds. 
 
 If cock P is so turned as to open cylinder/ 
 to the air, when the cross-head F moves, it will 
 cause pencil N to trace line c c^ , called the atmos- 
 pheric line. All vertical distances above this 
 line will represent pressures above the atmos- 
 phere. All vertical distances below this line 
 will represent pressures below the atmosphere. 
 The pressure of the atmosphere is 14.7 pounds 
 per square inch. Should a perfect vacuum be 
 found in cylinder A, then pencil N would go to 
 #!,#! representing to scale, by its vertical dis- 
 
AMMONIA COMPRESSOR. H 
 
 tances from line c c\ , 14.7 pounds per square inch 
 pressure. Now it should be clear that any varia- 
 tion of pressure in cylinder A will either raise or 
 lower pencil N in" relation to line c c l , and that any 
 motion of the cross-head F will move the paper 
 so that the pencil A^will vary its horizontal dis- 
 tance from line bb^. As the cross-head Amoves 
 with the same motion as that of piston B it is 
 evident that all points at a horizontal distance 
 from line b b 1 represent different positions of pis- 
 ton B, and all vertical distances from line cc l 
 represent pressures in cylinder A on piston B 
 at these positions. 
 
 Now let us see how the indicator pencil will 
 act under an actual test. Let us suppose that 
 piston B has just started in the direction of the 
 full arrow. Then pencil N at point a shows 
 the beginning- of piston's stroke and pressure, 
 ca, which is the back pressure (gauge). As the 
 piston B moves forward the gas flows into cyl- 
 inder A through suction valve C at the con- 
 stant back pressure from the expansion cham- 
 ber through pipe R, and the pencil traces the 
 line a a i . 
 
 Now the piston B having reached the end 
 of its stroke, B^ starts back in the direction of 
 the dotted arrow. In doing this it begins to. 
 compress the gas in the cylinder ^4, thus clos- 
 ing suction valve C; and as the pressure in cyl- 
 inder A becomes more and more, the pencil 
 traces the curved line a d (the compression,, 
 curve). When the piston reaches the position, 
 Z? 2 corresponding with the pencil point d, the. 
 pressure in cylinder A is a little greater than 
 that transmitted by pipe Q from condenser to 
 
 (2) 
 
10 INDICATING THK 
 
 the discharge valve D. From this position the 
 piston discharges the gas past the discharge 
 valve to the end of the stroke, the pencil in 
 the meanwhile tracing the wavy, peaked line, 
 db. The reason for the unevenness of this line 
 is the chattering of the discharge valve D. 
 The piston B now having reached its original 
 position, starts to go back in the other direction 
 (that of the full arrow) again. Now the dis- 
 charge valve D closes, due to the condenser 
 pressure, and the pressure in cylinder A falls to 
 that due to the suction or back pressure. As this 
 change takes place while the piston^ is changing 
 its motion from forward to backward, the cross- 
 head moves only a very small amount, and a nearly 
 vertical line, b a, is traced by the pencil N. 
 
 We have now followed the pencil through 
 rts travels, and the resulting diagram, aa l db 
 a, is the desired indicator diagram. This same 
 explanation can apply to a steam card by going 
 around the diagram the other way; bda l ab will 
 be a steam engine card, except that the line bd will 
 be more smooth, the line da^ will represent the 
 expansion line, d the point of cut-off, and a 1 a 
 the exhaust line. The practical forms of indi- 
 cators, such as are used to-day, do not differ 
 in principle from this elementary form; they 
 differ only in detail. The card / is carried on 
 an oscillating drum, which is oscillated by a cord 
 from the cross-head. The pencil is carried by a 
 straight line multiplying device. Another chap- 
 ter gives full description of the various standard 
 makes of indicators, so I will not go farther into 
 the subject of the construction of the indicator 
 at this point. 
 
AMMONIA COMPRESSOR. 11 
 
 CHAPTER II. 
 
 THE VALUE OF INDICATING A COMPRESSOR. 
 
 In this chapter I will try to demonstrate the 
 value of indicating" an ammonia compressor, of 
 doing- it regularly, and knowing- how to correctly 
 interpret the meaning- of the indicator card. I 
 have known men who were well up on indicator 
 practice, and who are intellig-ent engineers, to 
 let a compressor run for months, when a very 
 little knowledg-e of such methods as I hope to set 
 forth would have saved a great amount of worry 
 in regard to the quality of work being- done, and 
 a good many hundred dollars of expense on coal 
 bills. 
 
 All competent engineers know the names of 
 the various lines and are familiar with the gen- 
 eral appearance of the indicator card. They 
 know that the admission line is parallel to the 
 atmospheric line. The compression line rises 
 in an easy curve to the discharg-e line. The 
 discharge line is usually wavy or peaked, due to 
 the vibration of the discharge valves. The ad- 
 mission and discharge lines should be joined by 
 a nearly vertical line. The card should have a 
 square heel. We know that this square heel in- 
 dicates the amount of clearance. 
 
 In Fig. 1 the card has a square heel at , con- 
 sequently you say, " The clearance is small." 
 If the card had been like Fig. 2, you would say, 
 u Very bad; too much clearance," and you would 
 overhaul your compressor and make the clear- 
 ance what it should be. How many engineers 
 
12 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 
 
 13 
 
14 
 
 INDICATING THE 
 
AMMONIA COMPRESSOR. 15 
 
 go any farther than this? They take a card like 
 Fig-. 1, look at it, see that it has a good square 
 heel, and say, u This is a good card." As a re- 
 sult they g-o back to their other duties, thinking 
 that their compressor is doing- g-ood work. Here 
 is where many a good man makes a mistake. 
 He has done what he could, but for lack of a 
 practical way of applying thermodynamic reason- 
 ing to his card he can go no farther. 
 
 I am acquainted with an engineer who knows 
 a great deal about running a compression plant. 
 One day he handed me a card like Fig. 3. He 
 said, "Here is a good card." I took the card, 
 applied the simple rules to it, that I am about to 
 give, and found that the compressor was in a very 
 bad way. I doubt if there is an engineer who 
 can look at the card as given in Fig. 3, and say it 
 is a good or a bad card. It is impossible to tell 
 whether the compression line is good or bad by 
 a simple inspection. One may notice if the com- 
 pression line is very bad. Even then I think 
 there would not be one man in a great many that 
 could pass a valuable opinion on it. 
 
 What the engineer needs is a guide, some- 
 thing to compare his card with; something that 
 he knows is all right. In a picture or diagram 
 the way of comparing size and proportion is by 
 having some familiar object, as a man, for com- 
 parison. You may know then that the bridge 
 you are looking at is large or small, that you are 
 looking at the picture of a great cathedral or a 
 small church. In much the same way it is 
 necessary to have your comparison on an indi- 
 cator card. 
 
 This comparison or guide is the adiabatic 
 
16 
 
 INDICATING THI<; 
 
AMMONIA COMPRESSOR. 17 
 
 line. The isothermal line is interesting-, and 
 also serves as a guide, but it is a poor guide. 
 One cannot draw sound conclusions in all cases 
 from the isothermal line's relation to the com- 
 pression curve, as traced by the indicator pencil. 
 The adiabatic line is the true guide. The cal- 
 culation of this adiabatic line necessitates the 
 use of logarithms in calculating the fractional 
 powers of numbers. This may be difficult for 
 some engineers to do. Even our best engineers 
 will find that it is no small matter to figure 
 the adiabatic line for an indicator card. They 
 can do it easily enough, no doubt, but it will take 
 much more valuable time than they usually have 
 to devote to it. Consequently, I believe that if I 
 set forth a simple and practical way of obtaining 
 this line, engineers will, by using this method, 
 be able to get much better work out of their 
 machines. The owners of plants will also save 
 money that is needlessly wasted at present. 
 
 I reproduce Fig. 3 here in Fig. 4, having 
 drawn the adiabatic line a a on the card. This 
 card, that looked so good to my friend the engi- 
 neer, is now shown to be very bad. I told him 
 that probably the cylinder gasket between the 
 discharge port and the cylinder was blown out. 
 (The reasoning for this will be given later.) 
 Upon an examination of the compressor this was 
 found to be the case. The machine, I am sorry 
 to say, had been running for a long time in this 
 condition. Being a large machine, it had need- 
 lessly wasted a good deal of money while thus 
 running. 
 
18 
 
 INDICATING THE 
 
AMMONIA COMPRESSOR 19 
 
 CHAPTER III. 
 
 THE ADIABATIC CURVK. 
 
 An adiabatic line is a curve that represents 
 the adiabatic expansion or compression of a gas 
 or vapor. Adiabatic expansion or compression 
 is the expansion or compression of a gas or 
 vapor, without loss or gain of heat. It is 
 
 Op Op 
 
 expressed by pv^'^=p l 'v l ^ where p = initial 
 pressure, v= initial volume, p^ = final pressure, 
 27 ! = final volume, p = specific heat at constant 
 pressure, v = specific heat at constant volume. 
 c j- is called the ratio of specific heats; for am- 
 monia gas it is .3^^ = 1.3 .*. p v 1 -' 3 =p l v l *-*. 
 That is, the initial pressure times the 1.3 power 
 of the initial volume is equal to the final press- 
 ure times the 1.3 power of the final volume, p 
 and^j being absolute pressures. 
 
 In Fig. 5 the atmospheric line A A is the line 
 drawn by the indicator pencil when the indicator 
 cock is so turned that the atmospheric pressure 
 is on both sides of the indicator piston. Meas- 
 ure off perpendicular to and below A A the dis- 
 tance a b, equal to the atmospheric press- 
 ure, 14.7 pounds, using the same scale as that of 
 the indicator spring. Draw a line through b 
 parallel to A A. This line is the vacuum line 
 V V. Draw lines Z?..Z?and C C, perpendicular to 
 the atmospheric line A A, and tangent to or 
 touching the extreme right and left hand por- 
 tions of the diagram. I disregard the clearance, 
 as being too small to appreciably affect the re- 
 sults to be obtained. All pressures must be 
 
20 INDICATING THE 
 
 measured at right angles from the vacuum line 
 VV. The pressures are then the true or abso- 
 lute pressures. 
 
 Now divide line V V into ten equal parts. 
 The point where the right hand end of the dia- 
 gram cuts the line C C at c is the point of the 
 beginning of the compression. The vertical 
 distance from c to V V is the absolute back 
 pressure when measured on the same scale as 
 that of the indicator spring. 
 
 Let p= the absolute back pressure, as 
 measured from the vacuum line V V to c. At 
 the beginning of the compression, as the cylin- 
 der is full of gas, z' can be called 1. The most 
 convenient point from which to draw the adia- 
 batic line will be from the point of the begin- 
 ning of compression, or where v=l. Now as 
 I 1 - 3 = 1, we have /X 1 =/, z^ 1 3 or p^ = ^ 3 . 
 pi is the ordinate (or vertical distance from 
 VV) of any point, F,, on the adiabatic line for 
 a corresponding abscissa (or horizontal distance 
 on V Ffrom C C 1 ), p being the absolute back 
 pressure under consideration, and z 1 , varying 
 from 1 to 0. 
 
 The divisions of V V are now marked, as 
 shown on Fig. 5, viz.: .9, .8, .7, .6, .5, .4, .3, .2, .1 
 and 0. These points on V V indicating that 
 the volume at these points is either .9, .8, .7 to 
 .1 or 0, as the case may be. 
 
 .I 1<3 =the number which=l. 3 X logarithm of .1. 
 Log". .1=9.00000010 
 
 1.3 multiply by 1.3 
 11.70000013 
 
 3 +3 add and subtract 3 
 
 8.700000 10=lojr. of .05 
 .-. .OS=.l 1 ' 3 
 
AMMONIA COMPRESSOR. 21 
 
 Log". .2=9.30103010 
 
 1.3 multiply by 1.3 
 27903090 
 9301030 
 
 12.091339013 
 
 3 _ -j-3 add and subtract 3 
 9.0913390 10=log- of .123 
 .-. .123=.2 I<8 
 
 In like manner: 
 
 TABLE No. 1. 
 .I 1 ' 3 =3.050 
 .2 l ' 3 =.123 
 .3 1 ' s =.209 
 .4 1 - 3 =.304 
 .5'- s =.406 
 
 Now, having- the values of .I 1 3 to.9 1 3 we can 
 find values for p .^ p .%> p .% to^. 9 , by substituting 
 the corresponding- values of v^ , v , 2 to v, 9 in for- 
 
 P 
 
 t-=^ 
 
 p-= -* 
 
 P 6=: ~5v^ 
 
 As = -=- T7 
 
 A 3 =-^4 
 
 A.= li 
 # 
 
22 
 
 INDICATING THE 
 
 TABLE NO. 2. 
 
 ADIABATIC CONSTANTS. 
 
 l>> 
 
 15 
 
 16 
 
 17 IS 19 540 l & 
 
 its 
 
 4 
 
 P-! 
 
 17 2 
 
 18.4 
 
 19.5 20 6 21.8 22.9 24.1 25.2 
 
 264 
 
 27.6 
 
 P.* 
 
 20.0 
 
 21.4 
 
 22.7 24.3 25.4 26.7 28.1 29.4 
 
 30.7 
 
 32.1 
 
 P. 7 
 
 24.9 
 
 25.4 
 
 27.0 
 
 28.6 1 30.2 31.8 33.4 35.0 
 
 36.5 
 
 38.1 
 
 l'. ( 
 
 29.2 
 
 31.1 
 
 33.1 
 
 35.0 36.9 38.6 40.8; 42.8 
 
 44.7 
 
 46.7 
 
 P.r, 
 
 37.0 
 
 39.5 41.8 
 
 44.4 46.8; 49.3 51.8 54.3 
 
 56.7 
 
 59.2 
 
 P. 4 
 
 49.3 
 
 52.7 56.8 
 
 59.2 62.5! 65.8 69.ll 72.4 
 
 75.7 
 
 79.0 
 
 P.3 
 
 71.7 
 
 76.5 81.3 
 
 86.1 
 
 90.8; 95.6 100.3' 105.2 
 
 110.0 
 
 114.8 
 
 I 1 . 2 
 
 122.0 
 
 130.0 138.2 
 
 146.3 
 
 154.5 162.7 170.6 
 
 178.9 
 
 187.U 
 
 196.1 
 
 P.. 
 
 300.0 
 
 320.0 340.0 
 
 360. 
 
 380.0; 400.0 420.0 
 
 440.0 
 
 460.0 
 
 480.0 
 
 l>. 
 
 *5 
 
 26 
 
 x7 
 
 *8 
 
 * 
 
 30 
 
 31 
 
 tut 
 
 3 
 
 34 
 
 P- 8 
 
 28.7 
 
 29.8 
 
 31.0 
 
 32.1 
 
 33.2 
 
 34.4 
 
 35.6 
 
 36.7 
 
 37.9 39.0 
 
 I'- 
 
 33.4 
 
 34.7 
 
 36.1 
 
 37.4 
 
 38.8 
 
 4<U 
 
 41.4 
 
 42.8 
 
 44.1 45.4 
 
 P'7 
 
 39.7 
 
 41.3 
 
 42.8 
 
 44.5 
 
 46.2 
 
 47.7 
 
 49.3 
 
 50.8 
 
 52.4i 54.0 
 
 P' 
 
 48.7 
 
 50.6 
 
 52.5 
 
 54.4 
 
 56.4 
 
 58.3 
 
 60.3 
 
 62.2 
 
 64.2: 66.2 
 
 N 
 
 61.7 
 
 64.2 
 
 66.6 
 
 69.1 
 
 71.5 
 
 74.0 
 
 76.4 
 
 78.8 
 
 81. 4| 83.8 
 
 P- 
 
 82.3 
 
 85.5 
 
 88.8 
 
 92.2] 95.4 
 
 98.5 
 
 102.0 
 
 105.2 
 
 108.6' 111.8 
 
 P :. 
 
 119.6 
 
 124.2 
 
 129.0 
 
 133.9 138.7 
 
 143.4 
 
 148.2 
 
 153.0 
 
 157.8 162.5 
 
 p. ; , 
 
 203.2 
 
 211.4 
 
 219.4 
 
 227.8 235.8 
 
 244.0 
 
 252.0 
 
 260.0 
 
 268.2! 276.3 
 
 p.i 
 
 500.0 
 
 520.0 
 
 540.0 
 
 560.0 580.0J 600.0 
 
 620.0 
 
 640.0 
 
 6HO.O| 680.0 
 
 !>' 
 
 35 
 
 30 
 
 37 
 
 3 39 1 40 
 
 41 
 
 4 43 
 
 44 
 
 P- ; , 
 
 40.2 
 
 41.3 
 
 42.5 
 
 43.6 44.71 45.9 
 
 47.1 
 
 48.21 49.3 
 
 50.5 
 
 P-H 
 
 46.8 
 
 48.1 
 
 49.4 
 
 50.8 52.1! 53.4 
 
 548 
 
 56.1 
 
 57.4 
 
 58.8 
 
 P-7 
 
 55.6 
 
 57.2 
 
 58.8 
 
 60.4 62 63.6 
 
 65.2 
 
 66.7 
 
 68.3 
 
 69.8 
 
 I'M; 
 
 68.0 
 
 70.0 
 
 71.9 
 
 73.8 75.8 77 8 
 
 79.7 
 
 81.6 
 
 83.6 
 
 85.5 
 
 P-H 
 
 86.3 
 
 88.7 
 
 91.2 
 
 93.7 96.2 98.7 
 
 101.0 
 
 103.5 
 
 106.0 
 
 108.3 
 
 PM 
 
 115.1 
 
 118.4 
 
 121.7 
 
 125.0! 128 2 131.6 
 
 185.0 
 
 138.1 
 
 141.6 
 
 144.7 
 
 P-a 
 
 167.3 
 
 172.1 
 
 177.0 
 
 181.H 
 
 186.5 
 
 191.2 
 
 196.0 
 
 200.8 
 
 205.8 
 
 213.0 
 
 |., 
 
 284.7 
 
 292.7 
 
 300.7 
 
 309.0 
 
 317. (i 
 
 325.0 
 
 333.4 
 
 341.2 349.2 
 
 357.8 
 
 I'-i 
 
 7000 
 
 7200 
 
 740.0 
 
 760.0 
 
 780.0 800.0 
 
 820.0 
 
 840 0, 8600 
 
 880.0 
 
 !> 
 
 45 
 
 46 
 
 47 
 
 4* 
 
 49 
 
 50 
 
 51 
 
 5* 
 
 53 
 
 54 
 
 P'8 
 
 51.7 
 
 52.7 
 
 539 
 
 55.1 
 
 56.2 
 
 57.4 
 
 58.5 
 
 59.7 
 
 60.8 
 
 62.0 
 
 I'-H 
 
 60.2 
 
 61.5 
 
 62.8 
 
 64.1 
 
 65.4 
 
 66.8 
 
 68.1 
 
 69.4 
 
 70.8 
 
 72.1 
 
 P-7 
 
 71.5 
 
 73.1 
 
 74.7 
 
 76.3 
 
 77.8 
 
 79.5 
 
 81.0 
 
 82.6 
 
 84.2 
 
 85.8 
 
 !>. 
 
 87.5 
 
 89.4 
 
 914 
 
 93.3 
 
 95.2 
 
 97.2 
 
 99.1 
 
 101.0 
 
 103.0 
 
 105.0 
 
 P..-, 
 
 110.8 
 
 113.2 
 
 115.8 
 
 118.2 
 
 120.5 
 
 123.0 
 
 125.6 
 
 128.0 
 
 130.6 
 
 138.0 
 
 P- 1 
 
 148.0 
 
 1513 
 
 154.6 
 
 158.0 
 
 161.2 
 
 164.5 
 
 167.7 
 
 171.0 
 
 174.3 
 
 177.6 
 
 P-:t 
 
 215.0 
 
 220.0 
 
 224.8 
 
 229.5 
 
 234.2 
 
 239.0 
 
 243.8 
 
 248.6 
 
 253.5 
 
 258.1 
 
 P-2 
 
 366.0 
 
 3740 
 
 382.0 
 
 390.0 
 
 398.0 
 
 407.0 
 
 414.0 
 
 422.0 
 
 432.0 
 
 438.0 
 
 P., 
 
 900.0 
 
 920.0 940.0 
 
 960.0 
 
 980.0 
 
 1000.0 
 
 1020.0 
 
 1040.0 
 
 1060.0 
 
 1080.0 
 
 ! 
 
 55 
 
 56 
 
 57 
 
 58 
 
 59 
 
 60 
 
 j 
 
 !' 
 
 63.2 
 
 64.3 
 
 65.4 
 
 666 
 
 67.7 
 
 68.8 
 
 
 P- 8 
 
 73.5 
 
 74.8 
 
 76.1 
 
 77.5 
 
 78.8 
 
 80.1 
 
 
 P-7 
 
 82.4 
 
 89.0 
 
 90.5 
 
 92.2 
 
 93.7 
 
 95.3 
 
 i 
 
 P-G 
 
 107.0 
 
 10S.9 
 
 110.8 
 
 112.8 
 
 114.8 
 
 116.8' 
 
 
 P-r, 
 
 135.5 
 
 138.0 
 
 140.4 142.8 
 
 145.2 
 
 147.7 
 
 
 P.I 
 
 181.0 
 
 184.2 
 
 187.5 
 
 190.7 
 
 194.0 
 
 197.3 
 
 
 P. 3 
 
 263.0 
 
 267.8 
 
 272.4 
 
 277.2 
 
 282.0 
 
 287.0 
 
 
 P. 2 
 
 447.0 
 
 466.0 
 
 461.0 
 
 472.0 
 
 480.0 
 
 487.0 
 
 
 P-. 
 
 1100.0 
 
 1120.0 
 
 1140.01160.0 
 
 1180.0 
 
 1200.0 
 
 
AMMONIA COMPRKSSOK. 23 
 
 If now we give a value of 15 to p= fifteen 
 pounds absolute back pressure, and substitute 
 for z>. 9 1>3 to z*.! 1 ' 3 their values as given in table 
 No. 1 we will have : 
 
 A = .B\\ = 17 - 2 
 A = .^A= 20.0 
 
 A7 = .tf* = 24.9 
 Ae = .rfft = 29.2 
 As = . I'D 8 * = 37.0 
 A. = .#* = 49 - 3 
 As ^ .i 1 o 5 9 - 71.7 
 A. = . to =122.0 
 A i = -o^o =300.0 
 
 In like manner/. 9 to/., can be found for any 
 other value of/. These values have been calcu- 
 lated and are given in Table No. 2, up to p=60 
 pounds, advancing- by increments of one pound. 
 
 To plot the adiabatic line by means of Table 
 No. 2: Find in the horizontal line with p the 
 number corresponding- to the absolute back 
 pressure on your card. Then in the same verti- 
 cal column that contains your absolute back 
 pressure, and opposite/. 9 find the value of /. 9 . 
 Lay this off on line .9 (Fig-. 5) from VVto the 
 same scale as that of your indicator spring-. Do 
 the same for /. 8 /. 7 to /.,. You then have a 
 series of points throug-h which you draw the 
 smooth curve c^ c (Fig-. 5). This line , c is the 
 adiabatic line. 
 
 If the ammonia gas were compressed from 
 point c (Fig-. 9) up to the condenser pressure 
 in a perfectly tig-ht and non-conducting cyl- 
 inder without loss or gain of heat, then the 
 adiabatic line would be the curve traced by the 
 indicator pencil. Now if there is no leakag-e 
 past the valves or piston, this adiabatic line will 
 
24 INDICATING THK 
 
 in all ammonia compressors, as used to-day, 
 almost overlie the compression line of the card 
 for its whole length (see Fig-. 9). 
 
 The water jacket does not seem to affect the 
 compression line to any great extent. The 
 jacket of water may affect the relative positions 
 of the adiabatic and compression curves, during 
 the latter one-fourth or one fifth of the stroke 
 (when the gas is very hot); then the adiabatic 
 line will be seen to be slightly above the com- 
 pression line (see Fig-. 9). If the compression 
 line of the card does not follow very nearly the adia- 
 batic you can make up your mind that something' is 
 wrong in connection with the piston, valves or 
 gaskets of the compressor. This is, of course, as- 
 suming that the indicator is properly connected; 
 that the pipe leading from the cylinder to the in- 
 dicator is short and of small bore, say >^-inch 
 diameter, and that this pipe is well insulated 
 from the cooling effect of water in the jacket. 
 One thing is certain, the compression curve can 
 never lie above the adiabatic line if the compressor 
 is working properly. I will take up and discuss 
 the conclusions that can be drawn from the dif- 
 ferent relations of the adiabatic and compression 
 lines as soon as I have indicated how to draw the 
 isothermal line on the indicator card. 
 
AMMONIA COMPRESSOR. 
 
 CHAPTER IV. 
 
 THE ISOTHERMAL CURVE. 
 
 If there is no leakage to or from the cylinder 
 during- compression, and if the cylinder walls, 
 head and piston are perfect conductors of heat, 
 surrounded by a suitable cooling- medium, then 
 the temperature of the g-as will remain constant 
 during- its compression, and we will have the iso- 
 thermal line traced by the indicator pencil. No 
 ammonia compressor is running- to-day that will 
 give a compression line like this on the indicator 
 card. I doubt very much if an ammonia com- 
 pressor will ever be built that will give a card 
 where the compression line will approach it in 
 any great degree. There is such a great amount 
 of heat generated during compression that about 
 all that can be hoped for is to prevent too great an 
 accumulation of heat in the metals of the cylinder. 
 This is all that I believe is accomplished by the 
 water jacket, even in the best compressors built. 
 
 The isothermal line is more easily calculated 
 than the adiabatic. It is represented by the 
 formula ^^=^2^. That is, the initial pressure 
 times the initial volume is equal to the final 
 pressure times the final volume. Takings as 1, 
 
 then pXl=-fi\ x Vi or Pi = ^-> Now take values 
 of z>j from .9 to .1 as we did in the case of the 
 adiabatic line; then as p represents the back 
 pressure in pounds absolute, the different values 
 of p^ as f, 9 p.% p^ to^. t , will be found by 
 dividing the absolute back pressure p by the 
 
 (3) 
 
26 
 
 INDICATING THE 
 
 TABLE NO. 3. 
 
 ISOTHERMAL CONSTANTS. 
 
 p. 
 
 15 
 
 16 
 
 17 
 
 18 
 
 19 
 
 20 
 
 1 
 
 
 
 3 
 
 4 
 
 P. 9 
 
 16.7 
 
 17.8 
 
 18.9 
 
 20.0 
 
 21.1 
 
 22.2 
 
 23.3 
 
 24.5 
 
 25.6 
 
 26.7 
 
 P. 8 
 
 18.7 
 
 20.0 
 
 21.2 
 
 22.5 
 
 23.7 
 
 25.0 
 
 26.2 
 
 27.5 
 
 28.7 
 
 30.0 
 
 P.7 
 
 21.4 
 
 22.8 
 
 24.3 
 
 25.7 
 
 27.1 
 
 28.6 
 
 30.0 
 
 31.4 
 
 32.8 
 
 34.3 
 
 P.6 
 
 25.0 
 
 26.7 
 
 27.3 
 
 30.0 
 
 31.7 
 
 33.4 
 
 35.0 
 
 36.7 
 
 38.4 
 
 40.0 
 
 P.B 
 
 30.0 
 
 32.0 
 
 34.0 
 
 36.0 
 
 38.0 
 
 40.0 
 
 42.0 
 
 44.0 
 
 46.0 
 
 48.0 
 
 P. 4 
 
 37.5 
 
 40.0 
 
 42.5 
 
 45.0 
 
 47.5 
 
 50.0 
 
 52.5 
 
 55.0 
 
 57.5 
 
 60.0 
 
 P. 3 
 
 50.1 
 
 53.4 
 
 56.7 
 
 60.1 
 
 63.4 
 
 66.7 
 
 70.1 
 
 73.4 
 
 76.7 
 
 80.1 
 
 P 9 
 
 75.0 
 
 80.0 
 
 85.0 
 
 90.0 
 
 95.0 
 
 100.0 
 
 105.0 
 
 110.0 
 
 115.0 
 
 120.0 
 
 XT 2 
 
 P.I 
 
 150.0 
 
 160.0 
 
 170.0 
 
 180.0 
 
 190.0|200.0 
 
 210.0 
 
 220.0 
 
 230.0 
 
 240.0 
 
 P* 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 3O 
 
 31 
 
 338 
 
 33 
 
 34 
 
 P-9 
 
 27.8 
 
 28.9 
 
 30.0 
 
 31.1 
 
 32.2 
 
 33.3 
 
 34.4 
 
 35.6 
 
 36.7 
 
 37.8 
 
 P. 8 
 
 31.2 
 
 32.5 
 
 33.7 
 
 35.0 
 
 36.2 
 
 37.5 
 
 38.7 
 
 40.0 
 
 41.2 
 
 42.5 
 
 P. 7 
 
 35.7 
 
 37.1 
 
 38.6 
 
 40.0 
 
 41.4 
 
 42.8 
 
 44.3 
 
 45.7 
 
 47.2 
 
 48.6 
 
 P. 6 
 
 41.7 
 
 43.4 
 
 45.0 
 
 46.7 
 
 48.3 
 
 50.0 
 
 51.7 
 
 53.4 
 
 55.0 
 
 56.7 
 
 P. 5 
 
 50.0 
 
 52.0 
 
 54.0 
 
 56.0 
 
 58.0 
 
 60.0 
 
 62.0 
 
 64.0 
 
 66.0 
 
 68.0 
 
 P. 4 
 
 62.5 
 
 65.0 
 
 67.5 
 
 70.0 
 
 72.5 
 
 75.0 
 
 77.5 
 
 80.0 
 
 82.5 
 
 85.0 
 
 P. 3 
 
 83.4 
 
 86.7 
 
 90.1 
 
 93.4 
 
 96.7 
 
 100.1 
 
 103.4 
 
 106.7 
 
 110.1 
 
 113.4 
 
 P. 2 
 
 125.0 
 
 130.0 
 
 135.0 
 
 140.0 
 
 145.0 
 
 150.0 
 
 155.0 
 
 160.0 
 
 165.0 
 
 170.0 
 
 P.1 
 
 250.0 
 
 260.0 
 
 270.0 
 
 280.0 
 
 290.0 
 
 300.0 
 
 310.0 
 
 320.0 
 
 330.0 
 
 340.0 
 
 p 
 
 35 
 
 36 
 
 87 
 
 3$ 
 
 39 
 
 4O 
 
 41 
 
 42 
 
 43 44 
 
 P-9 
 
 38.9 
 
 40.0 
 
 41.2 
 
 42.3 
 
 43.4 
 
 44.5 
 
 45.6 
 
 46.7 
 
 47.8 
 
 48.9 
 
 P'8 
 
 43.7 
 
 45.0 
 
 46.2 
 
 47.5 
 
 48.7 
 
 50.0 
 
 51.2 
 
 52.5 
 
 53.7 
 
 55.0 
 
 P. 7 
 
 50.0 
 
 51.4 
 
 52.8 
 
 54.3 
 
 55.7 
 
 57.2 
 
 58.6 
 
 60.0 
 
 61.4 
 
 62.8 
 
 P. 6 
 
 58.4 
 
 60.0 
 
 61.7 
 
 63.4 
 
 65.0 
 
 66.7 
 
 68.4 
 
 70.0 
 
 71.7 
 
 73.4 
 
 P- 5 
 
 70.0 
 
 72.0 
 
 74.0 
 
 76.0 
 
 78.0 
 
 80.0 
 
 82.0 
 
 84.0 
 
 86.0 
 
 88.0 
 
 P-4 
 
 87.5 
 
 90.0 
 
 92.5 
 
 95.0 
 
 97.5 
 
 100.0 
 
 102.5 
 
 105.0 
 
 107.5 
 
 110.0 
 
 P.3 
 
 116.7 
 
 120.1 
 
 123.4 
 
 126.7 
 
 130.1 
 
 133.4 
 
 136.7 
 
 140.1 
 
 143.4146.7 
 
 P. 2 
 
 175.0 
 
 180.0 
 
 185.0 
 
 190.0 
 
 195.0 
 
 200.0 
 
 205.0 
 
 210.0 
 
 215.0j220.0 
 
 P.I 
 
 350.0 
 
 360.0 
 
 370.0 
 
 380.0 
 
 390.0 
 
 400.0 
 
 410.0 
 
 420.0 
 
 430.0|440.0 
 
 p. 
 
 45 
 
 46 
 
 47 
 
 48 
 
 49 
 
 50 
 
 51 
 
 52 
 
 53 
 
 54 
 
 P-9 
 
 50.0 
 
 51.2 
 
 52.3 
 
 53.4 
 
 54.5 
 
 55.6 
 
 56.7 
 
 57.8 
 
 58.9 
 
 60.0 
 
 P-8 
 
 56.2 
 
 57.5 
 
 58.7 
 
 60 
 
 61.2 
 
 62.5 
 
 63.7 
 
 65.0 
 
 66.2 
 
 67.5 
 
 P-7 
 
 64.3 
 
 65.7 
 
 67.2 
 
 68.5 
 
 70.0 
 
 71.4 
 
 72.8 
 
 74.3 
 
 75.7 
 
 77.2 
 
 P. 6 
 
 75.0 
 
 76.7 
 
 78.4 
 
 80.0 
 
 81.7 
 
 83.4 
 
 85.0 
 
 86.7 
 
 88.4 
 
 90.0 
 
 P. 5 
 
 90.0 
 
 92.0 
 
 94.0 
 
 96.0 
 
 98.0 
 
 100.0 
 
 102.0 
 
 104.0 
 
 106.0 
 
 108.0 
 
 P, 4 
 
 112 5 
 
 115.0 
 
 117.5 
 
 120.0 
 
 122.5 
 
 125.0 
 
 127.5 
 
 130.0 
 
 132.5 
 
 135.0 
 
 P.3 
 
 150.0153.4 
 
 156.7 
 
 160.0 
 
 163.4 
 
 166.7 
 
 170.0 
 
 173.4 
 
 176.7 
 
 180.0 
 
 p] 2 
 
 225.0230.0 
 
 235.0 
 
 240.0 
 
 245.0 
 
 250.0 
 
 255.0 
 
 260.0 
 
 265.0 
 
 270.0 
 
 P.'t 
 
 450.0|460.0 
 
 470.0 
 
 480.0 
 
 490.0 
 
 500.0 
 
 510.0 
 
 520.0 
 
 530.0|540.0 
 
 p. 
 
 55 
 
 56 
 
 57 
 
 58 
 
 59 
 
 60 
 
 
 
 
 
 P-9 
 
 61.2 
 
 62.3 
 
 63.4 
 
 64.5 
 
 65.6 
 
 66.7 
 
 
 
 
 
 P-8 
 
 68.7 
 
 70.0 
 
 71.2 
 
 72.5 
 
 73.7 
 
 75.0 
 
 
 
 
 
 P-7 
 
 78.5 
 
 80.0 
 
 81.4 
 
 82.8 
 
 84.3 
 
 85.7 
 
 
 
 
 
 P- 6 
 
 91.7 
 
 93.4 
 
 95.0 
 
 96.7 
 
 98.4 
 
 100.0 
 
 
 
 
 
 P. 5 
 
 110.0 
 
 112.0 
 
 114.0 
 
 116.0 
 
 118.0 
 
 120.0 
 
 
 
 
 
 P-4 
 
 137.5 
 
 140.0 
 
 142.5 
 
 145.0 
 
 147.5 
 
 150.0 
 
 
 
 
 
 P.3 
 
 183.4 
 
 186.7 
 
 190.1 
 
 193.4 
 
 196.7 
 
 200.1 
 
 
 
 
 
 P. 2 
 
 275.0 
 
 280.0 
 
 285.0 
 
 290.0 
 
 295.0 
 
 300.0 
 
 
 
 
 
 P.I 
 
 550.0 
 
 560.0 
 
 570.0 
 
 580.0 
 
 590.0 
 
 600.0 
 
 
 
 
 
AMMONIA COMPRESSOR. 
 
 27 
 
 volume z;. 9 , z>. 8 tox^. Let^> 15 pounds abso- 
 lute; then 
 
 /. 9 = |= 16.7 
 
 P.B- 15 = 18.7 
 
 A 7 = f 21.4 
 
 Ae- i- 25.0 
 
 As= 1= 30.0 
 
 />. 4 = \= 37.5 
 
 /.a= 1= 50.1 
 
 A S - 1= 75.0 
 
 /.!= if =150.0 
 
 In like manner ^. 9 to^. t can be found for any 
 other value of p. These values have been cal- 
 culated, and are given in Table No. 3, up to sixty 
 pounds. 
 
 To plot the isothermal line by means of Table 
 No. 3, proceed the same as explained in regard 
 to the adiabatic line. Fig". 6 shows a card upon 
 which this has been done. 
 
28 
 
 INDICATING THE 
 
AMMONIA COMPRESSOR. 29 
 
 CHAPTER V. 
 
 DISCUSSION OF THE ADIABATIC AND ISOTHERMAL 
 CURVES. 
 
 Now, let us discuss the conclusions that may 
 be drawn by inspecting- a card having- these 
 adiabatic and isothermal lines drawn on it. 
 First, let us discuss the adiabatic line. Take 
 the card shown by Fig-. 7. Here is seen that the 
 compression line is above the adiabatic line. 
 Something- is wrong-; what is it? Let us consider 
 what conditions could exist that would cause this 
 condition of affairs. It is evident that the press- 
 ure in the cylinder increases faster than could 
 be caused by the action of the piston. The same 
 conditions that cause the compression line to lie 
 above the adiabatic line during- compression 
 will cause the cylinder to be cheated out of 
 part of its full charg-e of g-as from the suction 
 pipe. The reason is that the hig-h pressure 
 gas from the condenser is leaking- into the 
 cylinder, either through leaky discharge valves, 
 their gaskets or the cylinder head gasket be- 
 tween the cylinder and the discharge port. 
 Therefore, we pump much less gas than we 
 should. It also takes more power to run the 
 compressor, as will be evident from the in- 
 creased area of the diagram. It will not take 
 long for a compressor to waste enough coal to 
 buy a first-class indicator, if this condition of 
 affairs is allowed to go on for any great length 
 of time. 
 
 In large machines the loss will be very great. 
 
30 
 
 INDICATING THE 
 
AMMONIA COMPRESSOR. 31 
 
 The engineer should take off the cylinder head 
 and examine the cylinder head gasket. If it 
 looks bad, replace it with a new one. Try the 
 valves with the fingers, and see that no scale or 
 foreign matter has attached itself to the valve 
 or its seat. Also examine the valve cage gas- 
 kets. After having done all that you can to 
 remedy the trouble, by a careful examination, 
 replace the cylinder head, and connect a press- 
 ure gauge to the indicator connection. Allow 
 the condenser pressure to act upon the outer 
 faces of the discharge valves. If the pressure, 
 as shown by the gauge, remains the same or in- 
 creases very slowly you have remedied the 
 difficulty. Otherwise, if the pressure increase 
 rapidly, you have not. 
 
 In nine cases out of ten the engineer will find 
 upon his first careful examination of the gaskets 
 and valves that the gasket is defective, or that 
 there is some foreign substance in the valve 
 seat. It may be that the valves need regrinding. 
 This is a point that is rather difficult to deter- 
 mine by a mere inspection, hence the pressure 
 gauge test. 
 
 Now let us examine the card as shown by Fig. 
 8. Here the compression line is some little dis- 
 tance below the adiabatic line ec. It approaches 
 the isothermal line dc. Some engineers might 
 thoughtlessly say: "What a fine card! how effi- 
 cient the water jacket must be!" etc. But, as 
 I said before, compressors "are not built that 
 way." By apparently being so good the card 
 gives ample evidence of a very bad state of affairs 
 within the compressor. 
 
 Let us see what conditions could give this 
 
32 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 33 
 
 result. It is evident that the pressure is not as 
 great at any point on the curve as it should be. 
 What is the cause of this? Some of the gas has 
 leaked out of the cylinder, either by leaky suc- 
 tion valves or their gaskets. The cylinder head 
 gasket may be defective between the suction 
 port and the cylinder, or you may have a leaky 
 piston. It is evident that a sort of rubber ball 
 action is going on in the cylinder. Part of the 
 gas is compressed and expanded between the 
 suction pipe and the cylinder, in place of being 
 discharged into the condenser. The gas is in 
 part pumped over and over again, thereby cut- 
 ting down the capacity of the machine. Remove 
 the cylinder head, examine the gaskets and 
 valves. Do all that you can by a careful inspec- 
 tion to make good the trouble. Then replace 
 the cylinder head and connect a pressure gauge 
 to the indicator connection. Compress the gas in 
 the cylinder so as to have a high pressure. Note 
 the pressureon the gauge. If it does not decrease, 
 or if it decreases very slowly, you have remedied 
 the trouble. If it decreases rapidly, either the 
 valves need regrinding, the piston needs new 
 rings or the cylinder should be rebored, or all 
 these troubles may exist at once. After having 
 had the valves reground if the pressure test, as 
 indicated above, still shows a rapidly decreasing 
 pressure, you would better call in the agent for 
 your machine, and let him decide whether the 
 piston rings or the boring of the cylinder are 
 at fault. 
 
 Fig. 9 shows the relations of the compression 
 curve and adiabatic line, e c, that your compressor 
 should give if in perfect condition. It has prob- 
 
34 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 35 
 
 ably occurred to you while reading- the above that 
 you might do all of your testing- with a pressure 
 gauge, in place of bothering- with an indicator. 
 This is true, in a way. Engineers who do not 
 own an indicator may make all the above tests 
 in regard to leaky valves, etc., by connecting a 
 pressure gauge to the indicator cock and pro- 
 ceeding as explained above. 
 
 The indicator card is a valuable permanent 
 record of what your compressor is doing. It 
 should be taken every week, dated and filed away 
 for future reference. A steel indicator is pre- 
 ferred for ammonia work. However, you may 
 use your composition indicator without fear of 
 damage if you keep it well oiled, and thoroughly 
 clean it as soon as you have finished your test. 
 
36 
 
 INDICATING THE 
 
AMMONIA COMPRESSOR. 37 
 
 CHAPTER VI. 
 
 FINDING THE HORSE POWER OF AN INDICATOR CARD. 
 
 To obtain the horse power, or work of com- 
 pression, represented by the indicator card it is 
 convenient to have a planimeter, and thus meas- 
 ure the area of the card. Then divide the area 
 thus found by the length of the card in inches, 
 and multiply the result by the scale of the spring- 
 used. The result is the mean effective pressure, 
 expressed as M. E. P. The mean effective press- 
 ure is the average pressure of the gas in the 
 cylinder from the beginning of suction to the end 
 of discharge. 
 
 I will not go into the method of using the 
 planimeter, as it is fully explained in the instruc- 
 tions that are furnished with each instrument, 
 and also in Parts II and III of this book. If you 
 are not fortunate enough to own a planimeter, and 
 cannot borrow one, you can obtain the M. E. P. as 
 follows : In Fig. 10 you should already have 
 your card divided into ten equal spaces, v l z'. 9 , 
 z>. 8 z/. 7 , etc. All that is necessary is to find the 
 average heights of these areas that are included 
 between the vertical lines as ^. 9 ^. 8 and the ad- 
 mission and compression or discharge lines. 
 Divide each of these spaces, v^v, 9 toz'.jZ',,, into 
 two equal parts, and draw through these divis- 
 ions the dotted lines as shown, which are num- 
 bered 1, 2 to 10. 
 
 Measure the length of each line from the 
 admission line to where it cuts the compression 
 or discharge curve, using the same scale as that 
 
38 INDICATING THE 
 
 of the indicator spring- used. Add tog-ether these 
 leng-ths and divide the result by 10. The quo- 
 tient is then the average height or the M.E.P. 
 Having the M. E.P., the horse power is readily 
 
 found by the following simple formula: 
 
 _ nXlXaX (M.E.P.) 
 ' ' 7 33,000 
 
 Where 72 strokes (not revolutions) per minute. 
 /=length of stroke in feet. 
 tf=area of piston in square inches. 
 M. E.P.=mean effective pressure. 
 
 Every engineer should know the constant for 
 his compressor. 
 
 It is evident that in the above formula 
 
 33,000 
 
 is constant for all conditions or tests. This value, 
 33 ooo * * s ^ e cons ^ an ^ for your compressor, and is 
 indicated by C. Therefore the horse power is 
 
 H. P.= CX n X (M. E. P.) 
 
 The horse power of the steam engine is 
 obtained in the same way. Only remember that 
 whereas your compressor may have been single- 
 acting, as is assumed for the above formula, your 
 engine is double-acting; therefore you should 
 multiply your strokes by 2, and your engine con_ 
 stant is approximately 33 ^ This is also the 
 constant for a double-acting compressor. In a 
 double-acting compressor or a steam engine the 
 area of one side of the piston must have de- 
 ducted from it the area of the piston rod, thus 
 giving the effective area of the piston. The true 
 constant for that side of the piston will then be 
 ~~33 000 * ai b e i n " the area of the piston rod in 
 square inches, The difference between the H. P. 
 of the steam engine and that of the compressor 
 is the friction of the machine. 
 
AMMONIA COMPRESSOR. 39 
 
 CHAPTER VII. 
 
 ACTUAL DISPLACEMENT OF A COMPRESSOR. 
 
 The actual displacement of the compressor 
 should be known. We know that the compressor 
 does not pump the weight of gas that it should, 
 as figured from its theoretical displacement, 
 the reason being, as stated by Prof. Deiiton, 
 that the gas is rarefied during suction by coming 
 in contact with the hot walls of the cylinder. 
 
 It is evident that if the gas is rarefied the 
 weight of a given volume of gas would be less 
 after rarefaction than before. Consequently 
 our compressor may vary in its actual capacity 
 from 70 per cent to 90 per cent of the theoretical 
 capacity, these two figures, 70 per cent and 90 
 per cent, being extreme cases that are rarely if 
 ever reached. The common value of the actual 
 capacity is from 75 per cent to 80 per cent of the 
 theoretical capacity. 
 
 My theory in regard to this rarefaction is 
 that as the gas enters the cylinder through the 
 narrow annular openings between the hot valves 
 and their seats, it is superheated and thus rare- 
 fied. There is only a brief interval between the 
 end of compression and the beginning of suction. 
 When suction begins the cylinder head and valves 
 are at their maximum temperature. Consequently 
 I could think of no better way of heating a gas 
 than that of forcing it through these narrow an- 
 nular openings, having hot metal surfaces to pass 
 by. The head and valves should be cooled by 
 some means other than the gas to be pumped. 
 
40 INDICATING THK 
 
 The gas should arrive at the cylinder as 
 near the temperature of the boiling- point of the 
 liquid ammonia, due to its back pressure, as 
 possible. Every degree of superheating- cuts 
 down the actual capacity of the compressor. It 
 is well known that a gas will expand T J- T of its 
 volume at F. for every degree of increase of 
 its temperature. The suction pipe to a com- 
 pressor should be thoroughly insulated. The 
 vapor from the expansion coils should not be 
 used for any cooling purpose whatsoever. Cool- 
 ing the liquid ammonia by means of the return 
 vapor is poor practice. To be sure, it is an 
 advantage to have the ammonia arrive at the ex- 
 pansion valve as cold as possible, but it is more 
 disadvantageous to warm up the vapor than not 
 to cool down the liquid with it. 
 
 It will be evident how poor the gas is in cool- 
 ing power when it is remembered that one pound 
 of vapor only has a cooling effect of .5 British 
 thermal units for every degree F. that it warms 
 up; while a pound of the liquid ammonia has while 
 vaporizing a cooling effect of 555 B. T. U., on an 
 average, or over one thousand times as much. 
 (Cool the liquid ammonia by any other available 
 means, but not by the return ammonia vapor.) 
 
 If the expansion coils or receptacle are prac- 
 tically built, if the coils are not too long, you will 
 have no trouble with liquid ammonia coming 
 over to your machine. Should you be unfortunate 
 enough to have a brine tank or expansion coils 
 that will squirt the liquid in the form of a spray 
 over to the compressor, you would better put a 
 separator in your suction pipe or else get a more 
 efficient brine tank or expansion coils. 
 
fi UNIVERSITY J 
 
 AMMONIA COMPRESSOR?**" 11 ""' 1^*^41 
 
 The talk about where the frost line should or 
 should not stop on the suction pipe is all bosh. 
 The frost should go right up to and around the 
 compressor cylinder if it is uninsulated. But 
 better still, the suction pipe and the cylinder 
 should be thoroughly insulated from the effect 
 of heat from outside sources. It is necessary 
 to know the temperature of the boiling point of 
 the ammonia in your expansion coils, and also 
 the temperature of the gas at the suction 
 entrance to your compressor. So long as the tem- 
 perature of the gas at the compressor is 5 or 
 10 F. above that of the boiling ammonia, 
 there will be no danger of getting liquid over 
 to your machine. 
 
 I would not let the gas get colder than 10 
 above that of the boiling point of the ammonia. 
 Probably there are hundreds of plants that can- 
 not follow this advice because they have squirt- 
 ing expansion coils. But the time is not far 
 distant when these plants will throw aside their 
 squirting coils and substitute expansion devices 
 which do not tend to squirt the liquid ammonia 
 like an atomizer. The liquid ammonia should 
 be allowed to boil in such a vessel that there is 
 ample room for the vapor to escape without 
 dragging along some of the liquid with it. I 
 have tried both kinds, squirting coils and proper 
 expansion vessels, and I would not take an or- 
 dinary coil brine tank for a gift unless I could 
 use it for some other purpose than for a brine 
 tank. 
 
 Now to determine the actual displacement of 
 your compressor. If you use the brine system 
 this can readily be done. Get the specific gravity 
 
 (4) 
 
42 INDICATING THK 
 
 of your brine by means of a hydrometer. If you 
 do not own a hydrometer, weigh equal volumes 
 of your brine and water. Divide the weight of 
 the brine by that of the water. The result is the 
 specific gravity of your brine. Now look up in 
 the tables (see Part IV) the corresponding 
 specific heat. Take several readings of the tem- 
 perature of your brine to tank and also of brine 
 from tank. Average the readings of the inlet 
 brine and also average those of the outlet brine. 
 Subtract the results. This is of course the 
 number of degrees that you have cooled your 
 brine through. 
 
 Find the weight of brine circulated per min- 
 ute by your pump. To do this, multiply the 
 strokes of your pump per minute by the length 
 of stroke in inches by the piston area in square 
 inches, and divide the result by 1,728; this gives 
 the cubic feet pumped per minute ; multiply this 
 by the weight of a cubic foot of your brine, to 
 obtain the weight pumped per minute. If your 
 pump is in good condition you should multiply 
 this result by .95, .95 being the probable actual 
 capacity of your brine pump. 
 
 Having now the weight in pounds of the brine 
 pumped per minute, multiply this weight by the 
 degrees F. change in temperature of your brine 
 in the brine tank, and multiply this result by 
 the specific heat of your brine. Now, divide 
 the above result by 200, and your final answer 
 is the tons of refrigeration that you are doing 
 per twenty-four hours. 
 
 One ton refrigeration in twenty-four hours 
 = 2,000 X 142 B. T. U. ; 142 B. T. U. is the latent 
 heat of liquefaction of ice. 2,000 X 142 = 284,000 
 
AMMONIA COMPRESSOR. 43 
 
 B. T. U. per twenty-four hours = ^^ = 200, 
 
 nearly, B. T. U. per minute. Twenty-four hours 
 = 1,440 minutes. Expressed in the form of a 
 formula, the above will read: 
 
 200 
 
 7? tons refrigeration per twenty-four hours. 
 
 / = temperature warm brine; t^ = temper- 
 ature cold brine. 
 
 5 = specific heat of brine. 
 
 TV = weight of brine circulated per minute. 
 
 Now, turn to your ammonia tables (see Part 
 IV) and find the weig-ht of a cubic foot of vapor 
 of ammonia at the back pressure at which you 
 are running-. Also look up the latent heat of 
 vaporization at this pressure, and the boiling- 
 point of the liquid ammonia. Take the tempera- 
 ture of your liquid ammonia just before it enters 
 the expansion valve. If your liquid pipe is insu- 
 lated, as it should be, this temperature will be 
 about the same as that of the water coming- 
 from your condenser. 
 
 Subtract the boiling- point of the ammonia 
 from this temperature. As the specific heat of 
 liquid ammonia is 1, this gives the number of 
 B. T.U. that the liquid must be cooled to bring- 
 it to the boiling- point. As this has to come from 
 the heat of vaporization, we subtract it from 
 the heat of vaporization, leaving- as a result the 
 available cooling- effect in B. T. U. of one pound 
 of liquid ammonia under our conditions. Ex- 
 pressed in the form of a formula, the above be- 
 comes 
 
 R X 200 200 X 
 
 ~~ ~ ~ 
 
44 INDICATING THK 
 
 r = heat of vaporization. 
 
 / 2 = temperature of ammonia at expansion 
 valve. 
 
 / 3 = temperature of ammonia at boiling- point. 
 
 W= pounds of ammonia circulated per minute. 
 
 Take the theoretical displacement in cubic 
 feet of your compressor per minute = D; mul- 
 tiply this by the weight of a cubic foot of vapor 
 of ammonia at the back pressure you are using 
 (see Part IV for tables). The result is the theo- 
 retical number of pounds of ammonia pumped 
 by your compressor = W l . Then D l the actual 
 
 capacity of your compressor; J9, =jy 
 
 EXAMPLES. 
 
 JVo. i. Required the horse power of card (see 
 Fig. id). 
 
 The compressor has two single-acting cylin- 
 ders, each twelve inches in diameter, stroke 
 eighteen inches; forty revolutions per minute; 
 scale of spring, 40. 
 
 Solution. Measure height of lines 1, 2, 3 to 
 10, with a 40 scale. They measure 88, 88, 88, 58, 
 35, 22, 13, 7, 4, 1. The sum of these figures is 
 404. Dividing by 10, the result is 40.4 = 
 M. E. P. 
 
 The constant for this compressor is 
 
 /Xfl 1.5 X 113 = 
 33,000 33,000 
 
 H. P. =CX XM. E. P. 
 . . H. P. = .00514 X 40 X 40.4 = 8.3. 
 
 As there are two cylinders, we must obtain 
 also the horse power of the other card ; if it is 
 the same as this card, then the horse power of 
 both cylinders is 8.3 X 2= 16.6. 
 
AMMONIA COMPRKSSOR. 45 
 
 If the horse power of the steam engine is 20, 
 then 20 16.6 = 3.4 = friction of machine = $# , 
 17 per cent of that of the steam cylinders. 
 
 This is very good. The friction will usually 
 be about 20 per cent. 
 
 No. 2. Required the refrigeration per day. 
 
 Brine pumped per minute = 667 pounds. 
 
 Change in temperature of brine =3 F. 
 t-t\. 
 
 Specific heat of brine = .8. 
 
 No. 3. Required the actual capacity of the com- 
 pressor, the theoretical capacity being 100 per cent. 
 
 Temperature of liquid ammonia to expansion 
 va lve = 70 F.; r = 572, * 3 = 28 for an absolute 
 back pressure of fifteen pounds. 
 
 y?=8, r = 572, ^ =70F., * 8 = 28 G F. 
 
 J~) vx O C\(\ 
 
 '. W == - - r I / 8 =3.018 pounds per minute. 
 r 2~r^ 
 
 The theoretical displacement of the compres- 
 sors is 113 X182X40 =94 cubic f eet er minute 
 
 The weight of a cubic foot of vapor of ammonia 
 at 15 pounds absolute is .056 pounds .*. 94X.056= 
 5.26 pounds^ W^ the theoretical capacity of the 
 
 W ^ 3.018 _,_ 
 compressor .*. jrr = D^ =--~-j =57.4 per cent = 
 
 rr -^ O ^D 
 
 the actual capacity of the compressor. This is 
 too small, consequently you should find out by 
 your adiabatic line where the trouble is. 
 
46 INDICATING THK 
 
 CHAPTER VIII. 
 
 SPECIAL FAULTS AS SHOWN BY CARDS. 
 
 Fig-. 11 shows a card when the suction valve 
 has too strong- a spring- or a valve that is inclined 
 to stick to its seat. (See distorted heel at a. } 
 
 Fig-. 12 shows a card where the line a a is 
 drawn to scale at a vertical distance above the 
 atmospheric line A A, equal to the suction press- 
 ure in the suction pipe. This shows that the 
 suction valve spring- is too strong-. 
 
 Fig". 13 shows a card where the line bb has 
 been drawn by connecting- the indicator to the 
 suction pipe and line a a by connecting- the indi- 
 cator to the discharg-e pipe. These lines should 
 be about as shown on the card. The lines a a 
 and bb can best be laid off to scale above A A, 
 corresponding- to the pressures in these pipes, 
 as shown by the pressure g-auge, althoug-h they 
 may be drawn by the indicator pencil if the suc- 
 tion and discharg-e pipes are tapped and con- 
 nected to the indicator. 
 
 Fig-. 14 shows a card with a line, a a, drawn to 
 scale at a distance above line A A equal to the 
 pressure in the discharg-e pipe. This indicates 
 too stiff discharg-e valve spring's. 
 
AMMONIA COMPRKSSOK. 
 
 47 
 
48 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 
 
 49 
 
50 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 51 
 
 CHAPTER IX. 
 
 WET COMPRESSION SYSTEM INDICATING. 
 
 Fig's. 15 and 16 are reproduced from cards 
 furnished me by the Fred W. Wolf Co., from an 
 18X30 inch Linde (wet compression system) 
 compressor, that were taken at the Western 
 Cold Storage Co. plant, on November 9, 1898, on 
 which I have drawn the adiabatic line c d* iso- 
 thermal line a d and the curve of saturation 
 /; d. The scale of spring- for these cards is 60. 
 These diagrams were given me as representative 
 cards, and seem to show that my reasoning-, as 
 applied to the dry compression or water jacket 
 machines, also applies to the wet compression 
 machines, particularly in Fig-. 16. 
 
 The wet compression machines differ from 
 the dry compression machines in that the former 
 injects liquid ammonia into the cylinder before 
 compression to take up the heat of compression, 
 while the latter surrounds the cylinder with a 
 water jacket for the same purpose. 
 
 THE CURVE OF SATURATION. 
 
 If the ammonia in the cylinder at the begin- 
 ning- of compression is a saturated vapor, and if 
 this condition (the state of saturation) is main- 
 tained throughout compression, then there will 
 be a different curve from the adiabatic and iso- 
 thermal traced by the indicator pencil. This is 
 called the curve of saturation. Any point on this 
 curve has its ordinate or vertical distance from 
 V V equal to the pressure in the cylinder, and 
 its abscissa or horizontal distance f rom d Fequal 
 
52 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR 53 
 
 to the relative volume in cylinder, the initial or 
 (cylinder full) volume being- 1. The ordinate 
 being- obtained by looking- up in a table of the 
 properties of saturated vapor of ammonia the 
 pressure corresponding- to the weig-ht of a cubic 
 foot of vapor at this point, this weig-ht being- the 
 product of the relative volume at this point and 
 the weig-ht of a cubic foot of vapor at the absolute 
 back pressure of the card. Curves b d^ Figs. 15 
 and 16, are curves of saturation. This curve 
 can be readily determined, approximately, from 
 the tables of the properties of saturated vapor of 
 ammonia in the following- manner: 
 
 Find from the tables the volume in cubic feet 
 per pound of the vapor at the absolute back 
 pressure of the card. Multiply this value by .9, 
 .8, .7, .6, .5, .4, .3, .2, .1, and note from the tables 
 the absolute pressures corresponding- to these 
 new volumes. These pressures are points on 
 the curve of saturation for values, .9, .8, .7, .6, .5, 
 .4, .3, .2, .1 of v. 
 
 For example, let the absolute back pressure 
 be twenty-one pounds per square inch. We find 
 from the tables that the number of cubic feet of 
 vapor per pound at this pressure is approxi- 
 mately 12.834. Then it follows that 
 
 12.834 X. 9=11. 55 cu. ft. per Ib. = 23.5 Ibs. per sq. inch 
 
 12.834 X. 8=10.27 " = 26.5 
 
 12.834X.7= 8.98 " =310 
 
 12.834X.6= 7.70 " = 35.8 
 
 12.834X.5= 6.42 " = 43.0 
 
 12.834X.4= 5.13 " = 54.6 
 
 12.834X.3= 3.85 " = 59.7 
 
 12.834X.2= 2.57 " =113.7 
 
 12.834X.1= 1.28 =232.0 
 
 Laying- off these values of pressures found on 
 the vertical lines to scale at volumes z;. fl , z>. 8 , v,^ 
 
54 
 
 INDICATING THK 
 
AMMONIA COMPRESSOR. 55 
 
 r .;> z '.5> r 4> v .$i ^.2* ^ i from the vacuum line, we 
 have the desired points on the curve of satura- 
 tion. 
 
 LIMITS OF COMPRESSOR. 
 
 From the above it follows that the adiabatic 
 curve will be traced when no heat is taken from 
 or given to the gas during- compression. The 
 isothermal curve will be drawn if the gas is 
 maintained at the same temperature that it has 
 at the beginning- of compression. Theoretically, 
 the g-as should be quite cold at the beginning- of 
 compression, say from 10 below 0^ F. to 10 
 above F. It will be seen that compressors 
 using water jackets could never maintain this 
 line unless they had jacket water as cold or colder 
 than these temperatures of gas at the beginning of 
 compression. As the jacket water usually rang-es 
 anywhere from 50 F. to 100 F., it is clear that 
 no heat can be taken from the compressed g-as 
 until it has reached this temperature. 
 
 This will explain why the actual curve of com- 
 pression follows the adiabatic curve part of the 
 way, and then tends toward the isothermal 
 curve. Where the actual compression curve 
 leaves the adiabatic, is the point of the stroke 
 where the jacket water is just beginning to "get 
 in its work." Therefore, if any one shows you 
 a card from a water jacketed dry compressor 
 that approaches the isothermal line for the first 
 half of the stroke, you would better make up 
 your mind that the card is wrong. 
 
 It will be seen in Figs. 15 and 16 that the curve 
 of saturation b d follows very closely the isother- 
 mal curve. In wet compression machines this 
 curve (the curve of saturation ) is aimed at bv 
 
56 INDICATING THE 
 
 injecting enough liquid ammonia into the cylin- 
 der to take up the heat of compression. If this 
 works as well practically as it does by theory, 
 then the curve of saturation is possible, and 
 therefore quite a reduced area of card is obtained, 
 indicating less power required to compress the 
 ammonia. 
 
 As it is not my desire to compare the relative 
 merits of the wet and dry compressors, I will 
 only add that to be fair when comparing one with 
 the other the question should be thoroughly in- 
 vestigated as to whether there are factors that 
 enter into the value of each machine other than 
 those shown by the indicator cards, and also 
 to note that cards 15 and 16, which are taken as 
 representative cards of the wet compression 
 system, are almost identical with what is ob- 
 tained from dry compression machines, particu- 
 larly Fig. 16. 
 
AMMONIA COMPRESSOR. 57 
 
 CHAPTER X. 
 
 INSTRUCTIONS FOR CONNECTING INDICATOR TO 
 MACHINE. 
 
 In regard to connecting- the indicator to the 
 compressor and arranging* for the drum motion, 
 I refer the reader to Chapters II and III of Part 
 II; how to take the diagrams, to Chapter IV, 
 Part II. I advise the use of a reducing- wheel, 
 as explained in Chapters VII and VIII, Part III. 
 
 The reducing- wheel will be found very accu- 
 rate and simple, and can be used with any of the 
 indicators described. Most of the indicator 
 manufacturers have these reducing- wheels in 
 stock, specially adapted to their particular make 
 of indicator. 
 
 In making- the ammonia connection with the 
 compressor cylinder, I advise the use of a 
 ^2-inch pipe connection, made from a solid piece 
 of iron or steel, having- a hole Y% inch diameter 
 drilled throug-h it. The reason for using- so 
 small a bore is to reduce the clearance as much 
 as possible. This connection can be capped 
 when not in use, or, better still, fitted with a 
 >^-inch cock, in which the hole in the plug- has 
 been bushed down to Y% inch diameter. I advise 
 the use of Coffin's averaging- instrument for 
 obtaining- the mean effective pressure of cards. 
 This instrument gives you the mean effective 
 pressure direct without the intermediate steps 
 of calculation necessary with the common plani- 
 meter, and also a neat board upon which to 
 measure the card. 
 
 (5) 
 
INDICATING 
 
 THE 
 
 REFRIGERATING MACHINE 
 
 PART II. 
 
 INDICATING THE STEAM ENGINE.* 
 
 CHAPTER I. 
 
 THE STEAM ENGINE INDICATOR. 
 
 The steam engine indicator, invented by 
 James Watt, and long- kept secret, was for many 
 years after its secret became known, strangely 
 neglected by most makers and users of steam 
 engines. 
 
 The earlier forms of the instrument, which 
 preceded that invented by Richards, were so 
 imperfect and so ill adapted to engines running 
 at other than very low speeds, that their indi- 
 cations were often misleading, more often unin- 
 telligible, and seldom of much value beyond 
 revealing the point of stroke at which the valves 
 opened and closed a most valuable service, 
 alone worth the cost of an indicator, but only a 
 small part of the service to be obtained from a 
 really good instrument. 
 
 The general principles, on which the best 
 type of steam engine indicator is designed, may 
 be briefly stated as follows: 
 
 A piston of carefully determined area is 
 nicely fitted into a cylinder so that it will move 
 
 *Reprinted by courtesy of Crosby Steam Gage and Valve Co. from 
 their book on indicator practice. 
 
 59 
 
60 INDICATING THE 
 
 up and down without sensible friction. The 
 cylinder is open at the bottom and fitted so that 
 it may be attached to the cylinder of a steam 
 engine and have free communication with its 
 interior, by which arrangement the under side 
 of the piston is subjected to all the varying 
 pressures of the steam acting- therein. The 
 upward movement of the piston due to the 
 pressure of the steam is resisted by a spiral 
 spring within the cylinder, of known elastic 
 force. A piston rod projects upward through 
 the cylinder cap and moves a lever having at its 
 free end a pencil point, whose vertical move- 
 ment bears a constant ratio to that of the piston. 
 A drum of cylindrical form and covered with 
 paper is attached to the cylinder in such a man- 
 ner that the pencil point may be brought in 
 contact with its surface, and thus record any 
 movement of either paper or pencil. The drum 
 is given a horizontal motion coincident with and 
 bearing a constant ratio to the movement of the 
 piston of the engine. It is moved in one direc- 
 tion by means of a cord attached to the cross- 
 head, and in the opposite direction by a spring 
 within itself. 
 
 When this mechanism is properly adjusted 
 and free communication is opened with the cyl- 
 inder of a steam engine in motion, it is evident 
 that the pencil will be moved vertically by the 
 varying pressure of steam under the piston; and 
 as the drum is rotated by the reciprocating mo- 
 tion of the engine, if the pencil is held in contact 
 with the moving paper during one revolution of 
 the engine a figure or diagram will be traced 
 representing the pressure of steam in the 
 
STEAM KNGINE. 61 
 
 cylinder, the upper line showing- the pressure 
 urging- the piston forward, and the lower the 
 pressure retarding- its movement on the return 
 stroke. 
 
 To enable the engineer to more correctly 
 interpret the nature of the pressures, the line 
 showing- the atmospheric pressure is drawn, 
 which indicates whether the pressure at any 
 part is greater or less than that of the atmos- 
 phere. 
 
 From such a diagram may be deduced many 
 particulars which are of supreme importance to 
 engine builders, engineers and the owners of 
 steam plants. 
 
 WHAT IS THE GOOD OF AN INDICATOR? 
 
 This question was asked by a young- engi- 
 neer who had come to examine and purchase an 
 indicator, with a view to rendering his services 
 of greater value to his employer, by a knowledge 
 and use of that instrument. His question was 
 overheard by the proprietor of a large establish- 
 ment, who took occasion to reply as follows: 
 
 "I will tell you what good an indicator did at 
 our works. Our steam engine was not giving 
 sufficient power for our business, and we ex- 
 pected to be obliged to procure a larger one. A 
 neighbor suggested that we have our engine 
 indicated to see if we were getting the best 
 service obtainable from it. This was done, and 
 the result was, that when the valves were prop- 
 erly adjusted and other slight changes made, 
 we had ample power, and the improved condition 
 of the engine made a reduction in our coal bills 
 during the following year of $500." 
 
62 INDICATING THE 
 
 Another case: An expert engineer was called 
 to indicate several locomotives just completed 
 by one of our prominent locomotive builders, 
 who had in use a large Corliss engine, which had 
 been running- only a few months. When the loco- 
 motives were indicated, the proprietor proposed 
 that the indicator be applied to the Corliss 
 engine, the engineer of which remarked: "Guess 
 you '11 find her all right, as she 's running- fine." 
 \The first card showd that nearly all the -work 
 ivas being done at one end of the cylinder. The 
 valves were chang-ed and a great improvement 
 was apparent in the running- of the engine, 
 while the actual consumption of coal was re- 
 duced from an averag-e of 3,370 pounds per day, 
 before the chang-e was made, to 2,338 pounds 
 afterward. 
 
 These two instances are valuable in showing 
 " the g-ood of an indicator." 
 
 Items of Information to be Obtained by the Use 
 of the Indicator. The arrang-ement of the valves 
 for admission, cut-off, release and compression 
 of steam. 
 
 The adequacy of the ports and passages for 
 admission and exhaust; and when applied to the 
 steam chest, the adequacy of the steam pipes. 
 
 The suitableness of the valve motion in point 
 of rapidity at the right time. 
 
 The quantity of power developed in the cyl- 
 inder, and the quantity lost in various ways: by 
 wire drawing, by back pressure, by premature 
 release, by mal-adjustment of valves, leakage, 
 etc. 
 
 It is useful to the designers of steam en- 
 gines in showing the distribution of horizontal 
 
STEAM ENGINE. 63 
 
 pressures at the crank pin, through the momen- 
 tum and inertia of the reciprocating- parts, and the 
 angular distribution of the tangential component 
 of the horizontal pressure; in other words, the 
 rotative effect around the path of the crank. 
 
 Taken in combination .with measurements of 
 feed water and the condensation and measure- 
 ment of the exhaust steam, with the amount of 
 fuel used, the indicator furnishes many other 
 items of importance when the economical genera- 
 tion and use of steam are considered. 
 
 For every one of these purposes it is import- 
 ant that the diagram traced by the indicator 
 should truly represent the path of the piston and 
 the pressure exerted on both sides of the piston 
 at every point of that path. 
 
 INDICATOR DIAGRAMS. 
 
 The degree of excellence to which steam 
 engines of the present time have been brought 
 is due more to the use of theindicator than to any 
 other cause, as a careful study of indicator 
 diagrams taken under different conditions of 
 load, pressure, etc., is the only means of becom- 
 ing familiar with the action of steam in an engine, 
 and of gaining a definite knowledge of the vari- 
 ous changes of pressure that take place in the 
 cylinder. 
 
 An indicator diagram is the result of two 
 movements, namely: a horizontal movement of 
 the paper in exact correspondence with the 
 movement of the piston, and a vertical move- 
 ment of the pencil in exact ratio to the pressure 
 exerted in the cylinder of the engine; con- 
 sequently, it represents by its length the stroke 
 
64 INDICATING THE 
 
 of the engine on a reduced scale, and by its 
 height at any point, the pressure on the piston 
 at a corresponding- point in the stroke. The 
 shape of the diagram depends altogether upon 
 the manner in which the steam is admitted to 
 and released from the cylinder of the engine; 
 the variety of shapes given from different en- 
 gines, and by the same engine under different 
 circumstances, is almost endless, and it is in the 
 intelligent and careful measurement of these that 
 the true value of the indicator is found, and no 
 one at the present day can claim to be a competent 
 engineer who has not become familiar with the 
 use of the indicator, and skillful in turning to 
 practical advantage the varied information which 
 it furnishes. 
 
 A diagram shows the pressure acting- on one 
 side of the piston only, during both the forward 
 and return stroke, whereon all the changes of 
 pressure may be properly located, studied and 
 measured. To show the corresponding press- 
 ures on the other side of the piston, another dia- 
 gram must be taken from the other end of the 
 cylinder. When the three-way cock is used, the 
 diagrams from both ends are usually taken on 
 the same paper, as in Fig. 9. 
 
 ANALYSIS OF THE DIAGRAM. 
 
 The names by which the various points and 
 lines of an indicator diagram are known and des- 
 ignated are given below, and their significance 
 fully explained. (See Fig. 1.) 
 
 The closed figure or diagram, CD E F G H, 
 is drawn by the indicator, and is the result of one 
 indication from one side of the piston of an 
 
STEAM ENGINE. 65 
 
 engine. The straight line A B is also drawn by 
 the indicator, but at a time when steam connec- 
 tion with the engine is closed, and both sides of 
 the indicator piston are subjected to atmospheric 
 pressure only. 
 
 The straight lines O X, O ^and/TT, when 
 required, are drawn by hand as explained below, 
 and may be called reference lines. 
 Y 
 
 H - 
 
 B 
 
 FIG. 1. 
 DIAGRAM LINES EXPLAINED. 
 
 The admission line C D shows the rise of 
 pressure due to the admission of steam to the 
 cylinder by the opening- of the steam valve. If 
 the steam is admitted quickly when the engine 
 is about on the dead center this line will be nearly 
 vertical. 
 
 The steam line D E is drawn when the steam 
 valve is open and steam is being- admitted to the 
 cylinder. 
 
 The point of cut-off E is the point where the 
 admission of steam is stopped by the closing of 
 the valve. It is sometimes difficult to determine 
 
66 INDICATING THE 
 
 the exact point at which the cut-off takes place. 
 It is usually located where outline of diagram 
 changes its curvature from convex to concave. 
 
 The expansion curve E F shows the fall in 
 pressure as the steam in the cylinder expands 
 behind the moving- piston of the engine. 
 
 The point of release F shows when the ex- 
 haust valve opens. 
 
 The exhaust line F G represents the loss of 
 pressure which takes place when the exhaust 
 valve opens at or near the end of the stroke. 
 
 The back pressure line ^^showsthe pressure 
 against which the piston acts during* its return 
 stroke. On diagrams taken from non-condens- 
 ing engines it is either coincident with or above 
 the atmospheric line, as in Fig. 1. On cards 
 taken from a condensing engine, however, it is 
 found below the atmospheric line, and at a dis- 
 tance greater or less according to the vacuum 
 obtained in the cylinder. 
 
 The point of exhaust closure H is the point 
 where the exhaust valve closes. It cannot be 
 located very definitely, as the change in pressure 
 is at first due to the gradual closing of the valve. 
 
 The compression ctirve H C shows the rise in 
 pressure due to the compression of the steam 
 remaining in the cylinder after the exhaust valve 
 has closed. 
 
 The atmospheric line A B is a line drawn by 
 the pencil of the indicator when its connections 
 with the engine are closed and both sides of the 
 piston are open to the atmosphere. This line 
 represents on the diagram the pressure of the 
 atmosphere, or zero of the steam gauge. 
 
STEAM ENGINE. 67 
 
 REFERENCE LINES EXPLAINED. 
 
 The zero line of pressure, or line of absolute 
 vacuum OX, is a reference line, and is drawn by 
 hand 14 T \ pounds by the scale, below and parallel 
 with the atmospheric line. It represents a per- 
 fect vacuum, or absence of all pressure. 
 
 The line of boiler pressure J K v& drawn by 
 hand parallel to the atmospheric line and at a 
 distance from it, by the scale equal to the boiler 
 pressure shown by the steam gauge. The differ- 
 ence in pounds between it and the line of the dia- 
 gram D E shows the pressure which is lost after 
 the steam has flowed through the contracted 
 passages of the steam pipes and the ports of the 
 engine. 
 
 The clearance line O T is another reference 
 line drawn at right angles to the atmospheric 
 line and at a distance from the end of the dia- 
 gram equal to the same per cent of its length as 
 the clearance bears to the piston travel or dis- 
 placement. The distance between the clearance 
 line and the end of the diagram represents the 
 volume of the clearance and waste room of the 
 ports and passages at that end of the cylinder. 
 
 DERANGED VALVE MOTION. 
 
 Fig. 2 shows two diagrams, one from each 
 end of the cylinder of a single-valve high press- 
 ure engine. This valve admits the steam over 
 its ends and exhausts inside. The derangement 
 is caused by the valve stem being too long; con- 
 sequently, at the back end the diagram shows 
 that the steam was admitted late, cut off early, 
 exhausted early and the exhaust valve closed 
 late, so that there is little or no compression. 
 
68 INDICATING THE 
 
 The diagram at the crank end shows the opposite 
 defects, viz.: Steam is admitted too soon and 
 carried too far on the stroke, the exhaust valve 
 is opened too late and closed too soon to get the 
 steam well out of the cylinder, causing 1 excessive 
 back pressure even greater than the boiler 
 pressure as shown by the loop at the top. 
 
 To remedy this derangement, the valve stem 
 should be shortened by the screw threads at one 
 end. It may then be found that the steam valve 
 
 FIG. 2. 
 
 opens a little too late at both ends, and it will 
 therefore be necessary to turn the eccentric 
 ahead on the shaft until both diagrams resemble 
 the figures shown in the heaviest lines. 
 
 UNITS OF MEASUREMENT AND TECHNICAL TERMS. 
 
 All substances of whatever nature are meas- 
 urable, and their measurements are referable 
 to some established unit, to be properly ex- 
 pressed and dealt with. An intimate knowledge 
 of some of these is indispensable to the engineer; 
 a few are here briefly defined: 
 
 The unit of linear measurement is the inch or 
 one-twelfth part of a foot. 
 
STEAM ENGINE. 69 
 
 The unit of superficial measurement is the 
 square inch. 
 
 The unit of so lid measurement'^ the cubic inch. 
 
 The unit of fluid pressure is the pound avoir- 
 dupois, consisting of 7,000 grains. 
 
 The unit of elasticity, or the pressure exerted 
 by elastic fluids, is, for popular use, one pound 
 on one square inch. 
 
 The unit of work or power is one pound lifted 
 twelve inches, or in other words, one pound of 
 force acting- through one foot of distance, and is 
 called the foot-pound. 
 
 Horse Power. The standard used for meas- 
 uring- the power of a steam engine is the horse 
 power. It was originally determined by James 
 Watt from experiments made on London dray 
 horses. It is considerably above the power of 
 an ordinary horse and is now simply an arbitrary 
 standard. It is equal to 33,000 foot-pounds ex- 
 erted during- one minute of time, or 550 foot- 
 pounds during- one second. As a foot-pound is 
 the amount of work done in raising one pound 
 through the distance of one foot, an equivalent 
 amount of work would be raising half a pound 
 two feet, or twelve pounds one inch. 
 
 Indicated horse power is the horse power of 
 an engine as found by the use of a steam engine 
 indicator, and is thus expressed: I. H. P. 
 
 Net horse power is the indicated horse power 
 of an engine, less the horse power which is con- 
 sumed in overcoming its own friction. 
 
 Wire drawing, as applied to steam, is the re- 
 ducing of its pressure, due to its flowing through 
 restricted or crooked pipes and passages. 
 
 Absolute pressure is pressure reckoned from 
 
70 INDICATING THE 
 
 absolute vacuum; in other words, it is the press- 
 ure of any fluid as shown by a pressure gauge, 
 with the weight or pressure of the atmosphere 
 added thereto. 
 
 Initial forward pressure in a cylinder is the 
 pressure acting on the piston at or near the 
 beginning of the forward stroke. 
 
 Terminal forward pressure is the pressure 
 above the line of perfect vacuum that would 
 exist at the end of the stroke if the steam had 
 not been released earlier. It may be found by 
 continuing the expansion curve to the end of the 
 diagram, as in Fig. 1 at F, or it may be taken at 
 the point of release. This pressure is always 
 measured from the line of perfect vacuum, hence 
 it is the absolute terminal pressure. 
 
 Mean effective pressure is the average of all 
 the steam pressure which acts on one side of the 
 piston to move it forward, less all the steam 
 pressure which acts on the other side of the 
 piston to retard it. It is expressed thus : M. E. P. 
 
 Piston displacement is the space in the cylin- 
 der swept through by the piston in its travel. 
 It is reckoned in cubic inches, and is found by 
 multiplying the net area of the piston in inches, 
 by the length of stroke in inches, allowance being 
 made for the piston rod. 
 
 Clearance is all the waste room or space at 
 either end of the cylinder, between its head and 
 the piston when on a dead center, including the 
 counterbore and the ports, up to the face of the 
 closed valves. 
 
 Sensible heat is the temperature of any body, 
 as air, water or steam, which may be measured 
 by the thermometer. 
 
STEAM ENGINE. 71 
 
 Specific heat is the quantity of heat required 
 to raise one unit of weight of the substance 
 through one degree of temperature, measured 
 in thermal units.- When the pressure remains 
 constant Regnault found the specific heat for 
 superheated steam to be 0.4805 of a thermal 
 unit. 
 
 The unit of heat, or thermal unit, is the quan- 
 tity of heat required to raise the temperature of 
 one pound of water from 62 to 63 F. 
 
 Mechanical Equivalent of Heat. It has been 
 found by experiment that if one pound of pure 
 water at 62 F. be raised to 63 F., that energy 
 is exerted equivalent to lifting 778 pounds one 
 foot high, or one pound 778 feet high. This 
 energy is called the mechanical equivalent of one 
 thermal unit of heat, and it is usually designated 
 by the letter / and its reciprocal, or T fg, by A. 
 
 Saturated Steam. When steam is formed in 
 a closed vessel in contact with its own liquid, it 
 is said to be saturated, and it will have a certain 
 definite pressure and density corresponding to 
 each different temperature. If, at the same 
 time, the steam contains no liquid in suspension, 
 it is said to be dry and saturated. 
 
 Superheated Steam. If, after all the liquid 
 has been converted into steam, more heat be 
 added, the temperature will rise and the steam 
 is said to be superheated, because its tempera- 
 ture will be greater than that corresponding to 
 saturated steam of the same pressure. The 
 amount of superheating will vary according to 
 the conditions under which it occurs that is to 
 say, whether the volume of the containing vessel 
 varies or remains constant. 
 
72 INDICATING THE 
 
 CHAPTER II. 
 
 HOW AND WHERE TO ATTACH THE INDICATOR. 
 
 The indicator should be attached close to the 
 cylinder whenever practicable, especially on 
 high speed engines. If pipes must be used they 
 should not be smaller than half an inch in diame- 
 ter, and as short and direct as possible ; if long- 
 pipes are needed they should be slightly larger 
 than half an inch, and covered with a non-con- 
 ducting material. 
 
 FIG. 3. 
 
 Diagrams should be taken from both ends of 
 the cylinder of an engine. If the diagram from 
 one end is satisfactory it is not safe to assume 
 that one taken at the other end will be equally 
 so; it is often otherwise, owing to the varying 
 conditions usually found; the lengths of thor- 
 oughfares, the points of valve opening and clos- 
 ing, and the lead, are variable and should be 
 carefully adjusted to secure the best results, and 
 this can only be done through the instrumen- 
 tality of an indicator. 
 
 When only one indicator is employed, it is 
 generally attached to a three-way cock (Fig. 3), 
 
STEAM ENGINE. 73 
 
 which is located midway in the line of pipe, con- 
 necting- the holes at either end of the cylinder; 
 by this arrangement diagrams can be taken 
 from either end simply by turning- the handle of 
 the three-way cock. In such a case, the second 
 diagram should be taken as quickly as possible 
 after the first, so as to be under like conditions 
 of speed, pressure and load. 
 
 The indicator can be used in a horizontal posi- 
 tion, but it is more convenient to take diagrams 
 when it is in a vertical position, and this can gen- 
 erally be -obtained, when attaching to a vertical 
 engine, by using a short pipe with a quarter up- 
 ward bend. No putty or red lead should be used 
 in making any joints, as particles of it may be 
 carried by the steam into the indicator, and 
 great harm result therefrom ; if a screw fits 
 loosely, wind into the threads a little cotton 
 waste, which will make a steam tight joint. The 
 indicator should never be set so as to communicate 
 with thoroughfares where a current of steam will 
 jlow past the orifice leading to the indicator, as the 
 diagrams taken under such conditions would be of 
 no practical value. 
 
 The cylinders of most modern steam engines 
 are drilled and tapped for the indicator and have 
 plugs screwed into the holes, which can readily 
 be removed and the proper indicator connections 
 inserted. But when this is not the case, the 
 engineer should be competent to do it under the 
 directions here given. 
 
 When drilling holes in the cylinder the heads 
 should be removed if convenient, so that one 
 may know the exact position of the piston, the 
 size of ports and passages, and be able to remove 
 
 (6) 
 
74 INDICATING THE 
 
 every chip or particle of grit which might other- 
 wise do harm in the cylinder or be carried into 
 the indicator and injure it. When the heads can- 
 not be taken off, it can be arranged so that a little 
 steam may be let into the cylinder, when the 
 drill has nearly penetrated its shell, so that the 
 chips may be blown outward, care being taken 
 not to scald the operator. 
 
 Each end of the cylinder should be drilled 
 and tapped for one-half-inch pipe thread. The 
 holes must always be drilled into the clearance 
 space, at points beyond the range of the piston 
 when at the end of the stroke, so as not to be ob- 
 structed by it, and away from steam passages, to 
 avoid strong currents of steam. By placing the 
 engine on a dead center, it is easy to tell how much 
 clearance there is, and the hole should be drilled 
 into the middle of this space; the same process 
 should be repeated at theotherendof the cylinder. 
 
 On horizontal engines the most common prac- 
 tice is to drill and tap holes in the side of the 
 cylinder at each end, and insert short half-inch 
 pipes with quarter upward bends, into which the 
 indicator cocks may be screwed ; on some hori- 
 zontal engines it may be more convenient to drill 
 and tap into the top of the cylinder at each end, 
 and screw the cocks directly into the holes. 
 On vertical engines, for the upper end of the 
 cylinder the cock may be screwed into the upper 
 head or cover, and for the lower end, into the side 
 of the cylinder, after drilling and tapping the 
 necessary hole. It is preferable to drill the holes 
 in the sides of a cylinder rather than the heads, 
 because the former gives better results and 
 requires less pipe and fittings. 
 
STKAM ENGINE. 75 
 
 Before deciding- just where to drill the holes 
 it is wise to consider all the conditionsof the case 
 and devise the whole plan for indicating 1 the 
 engine. 
 
 Sometimes a drum motion can be erected 
 more advantag-eousry in one place or position in 
 the engine room than another, or one kind may 
 be better adapted for a given place than another. 
 Again, the type of engine and position of the 
 steam chest, the kind of cross-head and the best 
 means for attaching to it, the position of the 
 eccentric, its rods and connections, -all should 
 be taken into account when determining- the best 
 places to drill the cylinder and locate the indica- 
 tor, in order to secure a proper connection with 
 the reducing motion, a perfectly free passag-e for 
 steam to the indicator and the most convenient 
 access to the instrument for taking diagrams. 
 
76 
 
 INDICATING THK 
 
 CHAPTER III. 
 
 THE DRUM MOTION. 
 
 The motion of the paper drum may be derived 
 from any part of the engine which has a move- 
 ment coincident with that of the piston. In 
 general practice and in a large majority of cases 
 the cross-head is chosen as being- the most relia- 
 ble and convenient part, 
 and for this purpose it is 
 drilled and tapped for an 
 iron stud or pin to be 
 screwed in to it. This stud 
 should be long- enough, in 
 most cases, to reach about 
 six inches beyond the 
 outer surface of the cyl- 
 inder. The movement of 
 the cross-head must be 
 reduced from whatever it 
 actually is, to about three 
 inches, or the leng-th of 
 the diagram to be taken, 
 FlG - 4 - and this reduced motion 
 
 must be in exact ratio to the motion of the piston. 
 To obtain this reduced motion a variety of 
 means may be employed, any one of which calls 
 forth the ingenuity and skill of the engineer. 
 The reducing lever in some one of its various 
 forms is easily made, and can be adapted to suit 
 almost any conditions. 
 
 The slotted lever (Fig. 4) is a common form 
 of this device, and answers very well for large 
 
STEAM ENGINE. 
 
 77 
 
 and quick running- engines. It should be made 
 of straight grained pine, one inch or more in 
 thickness, about six inches wide at the top, where 
 there is a hole for a bolt, and tapering- to four 
 inches at the bottom, where there is a slot about 
 six inches long- and of the same width as the 
 diameter of stud in the cross-head, which gives 
 it a vibrating motion. This lever is suspended 
 by a bolt from the ceiling or from a truss or 
 frame overhead prepared for that purpose, in 
 such a manner as to permit it to swing edgewise 
 and parallel with the guides. 
 It must hang plumb when the 
 stud in the cross-head is in the 
 slot and the piston is at mid- c 
 stroke; in this position the 
 slot should extend an inch or 
 more above the stud, for play. 
 
 To find the point at which 
 to attach the cord, divide the 
 length of the lever by the 
 length of the piston stroke, and 
 multiply the quotient by the 
 required length of the dia- 
 gram, and the product will be the proper distance 
 from the pivot to the point of attachment. 
 
 The slotted lever with a cord arm, which can 
 be set at any desired angle to the main lever, is 
 shown in Fig. 5. This is a convenient device 
 when it is found necessary to attach the reduc- 
 ing motion to the floor, which may be done by 
 fastening down with lag screws or bolts a suit- 
 able piece of timber, to which the lever is pivoted, 
 so that it will vibrate edgewise with the move- 
 ment of the engine. It may also be attached 
 
 FIG. 5. 
 
78 
 
 INDICATING THE 
 
 overhead in the same manner as the plain slotted 
 lever. The lever must stand plumb when the 
 piston is at mid-stroke, at which time the cord 
 arm, a, must be fixed at such an angle as to have 
 the cord, c, draw at right angles to its longitu- 
 dinal axis, and in the plane of its vibration; the 
 direction of the cord may have any necessary 
 angle with horizontal line, but it must be at right 
 
 angles with the cord 
 arm at mid-stroke. 
 The point of attach- 
 ment for the cord is 
 found by the same 
 arithmetical rule as 
 given for Fig. 4. 
 
 The Brumbo pul- 
 ley, shown in Fig. 6, 
 is another form of 
 reducing lever, and 
 one more generally 
 used by engineers, 
 especially on loco- 
 { 1 motives. It can be 
 
 FIG. 6. quickly and cheaply 
 
 made, and can be used on almost any engine. The 
 swinging lever, E, is a strip of pine board three 
 or four inches wide, and at least one and a half 
 times as long as the piston stroke. It is sus- 
 pended by a bolt or screw from a frame or truss 
 overhead, constructed for that purpose, and is 
 connected at its lower end by the wooden link, F, 
 of convenient length (say about one-half the 
 length of stroke) to the usual stud or pin at- 
 tached to the cross-head. The sector, S, also 
 made of wood, with a groove in its lower circular 
 
STEAM ENGINE. 79 
 
 edge for the cord to run in, is screwed to the 
 upper end of the pendulum, so that its center 
 will exactly coincide with the center of the bolt 
 on which it swing's. The radius of the sector, 
 which is necessary to give the proper motion to 
 the drum to obtain the desired length of the 
 diagram, can be found as follows: Divide the 
 length of the lever by the length of the piston 
 stroke, and multiply the quotient by the length 
 of the diagram desired, and the product will be the 
 required radius, all the terms being expressed 
 in inches. For example: If the lever is thirty 
 inches long and the piston stroke twenty inches, 
 and we wish to obtain a diagram three inches 
 long, we have 30 inches -*- 20 inches = 1> inches; 
 1>2 inches X 3 inches 4j^ inches, the radius 
 required to give a 3-inch diagram. 
 
 When the conditions are favorable, the lever 
 should be hung so that it will swing in a vertical 
 plane, parallel with the guides and in line with 
 the indicator, as this arrangement is the most 
 simple, and the use of guide pulleys is avoided. 
 It is not absolutely necessary, however, that the 
 lever shall swing in a vertical plane, but it may 
 swing in a plane at any angle thereto, where the 
 conditions require it. In such cases, a man's 
 ingenuity and inventive faculty must aid him. A 
 link made of a thin strip of steel, that will twist 
 a little, is in some cases very convenient. 
 
 When the cross-head is at mid-stroke the lever 
 must hang plumb, and the pin which connects its 
 lower end to the link must be as much below the 
 line of motion of the stud in the cross-head H, 
 as it sweeps above that line at either end of the 
 stroke. See cut for illustration of this point, 
 
80 
 
 INDICATING THE 
 
 which is important. The cord must lead from 
 the sector in about the same plane with its swing*. 
 Carrying pulleys should be avoided whenever 
 possible, but whatever number is necessary 
 should be firmly placed. The swing-ing- arm of 
 the guide pulley on the indicator should always 
 be adjusted in the direction from which the cord 
 is received. Some engines are furnished with a 
 drum motion of this kind, made of steel with 
 nicely fitted joints, which can be readily attached 
 to the engine, and are very convenient to use. 
 
 FIG. 7. 
 
 The pantograph, illustrated in Fig. 7, is 
 another style of reducing motion. Although 
 theoretically it gives a perfect motion, owing to 
 its many joints it may soon become shaky and 
 give erroneous results, unless it is very nicely 
 made and carefully used. When the indicator 
 is applied to the side of the cylinder the panto- 
 graph works in a horizontal plane. The pivot end 
 B rests on a post or other support set opposite 
 to the middle of the guides, and the working end 
 A receives motion from the cross-head to which 
 
STEAM ENGINE. 81 
 
 it is attached by a suitable iron with a hole drilled 
 in it for the stud A to work in. By ad j usting the 
 support for the pivot end to the proper height and 
 at a proper distance from the guides, the cord 
 may be carried directly from the pin E to the 
 indicator without the need of carrying- pulleys. 
 
 The reducing -wheel is another device for giv- 
 ing the proper motion to the paper drum. Al- 
 though old in principle, and as formerly made 
 not highly approved by experienced engineers, 
 this style is now coming- into more g-eneral use, 
 and the superior manner in which it is desig-ned 
 and constructed seems to warrant this chang-e 
 especially on short-stroke engines which re- 
 quire only a short cord. Its portability and con- 
 venience of application also tend to make it a 
 favorite, especially with young engineers. It is 
 usually clamped to the frame of the engine, in a 
 direct line from the indicator to the stud in the 
 cross-head, thus avoiding the need of guide pul- 
 leys. This is considered the only practical drum 
 motion for an oscillating engine. 
 
 Whatever drum motion mechanism is used, 
 its accuracy can be easily tested in the following 
 manner : Lay off on the guides, points at one- 
 quarter, one-half and three-quarters of the 
 stroke. Connect the indicator with the drum mo- 
 tion in the same manner as for taking diagrams. 
 When the cross-head is on either dead center, 
 touch the pencil to the paper and make a vertical 
 mark, and in the same way make vertical marks 
 when the cross-head reaches each successive 
 quarter point on the guides. If the marks are 
 exactly at fourths on the card, the motion of the 
 cross-head has been accurately reduced. 
 
82 
 
 INDICATING THE 
 
 The directions here given for constructing 
 and arranging- drum motions are general; special 
 cases may require modification of the forms and 
 special adaptation of the means here described, 
 all of which call forth the ingenuity and skill of 
 the engineer. 
 
 Fig. 8 X shows a pantograph device at mid- 
 stroke. This is made of bar iron nicely riveted 
 together. The indicator cord may be attached 
 at b. The end a is attached to 
 a pin on the cross-head. The 
 fixed fulcrum is at c. a, b and 
 c must always lie in the same 
 straight line, and e d, b n, par- 
 allel and equal to f g. Also, 
 af : nf= stroke of piston to 
 length of indicator diagram. 
 
 Fig. 8 Y is a device used at 
 the Massachusetts Institute of 
 Technology. f\<$> a rod mov- 
 ing in a slide parallel to the 
 piston rod. Link b d is at- 
 tached toy, and link a e to the 
 cross-head. , b and c must 
 always lie in the 
 same straightline. 
 
 stroke of piston to 
 length of indi- 
 cator diagram. 
 The cord is hook- 
 ed on a pin at^; it 
 is well to have a 
 pin for each indi- 
 cator used. 
 
STEAM ENGINE. 83 
 
 Fig-. 8 Z is a device by Armand Stevart for 
 long- strokes, a and b are fixed ends of cord 
 wrapped around pulley D. Indicator cord is 
 attached to small pulley d and passes around 
 g-uide pulley e. D and <^are attached to cross- 
 head. Dia. D -*- dia. d = stroke piston -*- the 
 difference between stroke of piston and leng-th 
 of card. 
 
84 INDICATING THE 
 
 CHAPTER IV. 
 
 HOW TO TAKE DIAGRAMS. 
 
 When the indicator has been placed in posi- 
 tion and a correct drum motion obtained, it is next 
 necessary to adjust the length of the cord so that 
 the drum will not strike the stops at either ex- 
 treme of its rotation. Find about the length of 
 cord required and make a loop at the end, so 
 that when the hook on the short piece of cord 
 connected with the indicator is hooked in, the 
 cord will be a little too long. Take up the extra 
 length by tying knots in the cord until the drum 
 rotates without striking either stop. This 
 method may seem rather primitive, but it has 
 been adopted by many of our best engineers 
 after trying the various devices for shortening 
 the cord. 
 
 The paper or card should be wrapped 
 smoothly around the drum ; have the two lower 
 edges come evenly together as they meet after 
 being passed under the clip; when in this posi- 
 tion, the paper may be slipped down as far as 
 the shoulder in the clip; a little practice will en- 
 able one to do this with facility. 
 
 After the cord is adjusted and a paper 
 wrapped on the drum, open the indicator cock 
 and allow the piston to play until the instrument 
 has been thoroughly warmed by the steam, then 
 gently press the pencil on the paper by the 
 wooden handle. After the pencil has remained 
 on the paper during one or more revolutions, 
 draw it back, close the cock and again gently 
 
STEAM ENGINE. 85 
 
 press the pencil on the paper and take the at- 
 mospheric line. 
 
 The pressure of the pencil on the paper can 
 be adjusted by screwing- the handle in or out, 
 so that when it strikes the stop there will be 
 just enough pressure on the pencil to give a 
 distinct fine line. The line should not be heavy, 
 as the friction necessary to draw such a line is 
 sufficient to cause errors in the diagram. 
 
 After the diagram has been taken disconnect 
 the cord, to avoid any unnecessary wear on the 
 drum. 
 
 On locomotives and engines, the speed of 
 which is so great that it is difficult to hook in the 
 loop, arrangements can easily be made so this 
 will not have to be done. At the further end of 
 the arc on the Brumbo pulley insert an ordinary 
 screw eye. Drive another screw eye firmly into 
 a small hole drilled in the center of the end of 
 the bolt on which the bar swings. The cord from 
 the indicator can then be carried through the eye 
 at the end of the arc, and then through the eye 
 in the end of the bolt and back to some conven- 
 ient point near the instrument where it can be 
 easily reached by the operator. Connect the cord 
 with the instrument and draw it through the 
 eyes until the drum will not strike the stops at 
 its extreme positions. Then at the point of the 
 cord just before the eye at the end of the arc, tie 
 a small ring. When the cord is drawn taut by 
 the operator, the ring stops the cord when it has 
 been drawn through just enough to give the 
 proper motion to the drum. As soon as the 
 diagram and atmospheric line have been taken, 
 slacken the cord and the drum will stop. This 
 
86 INDICATING THE 
 
 arrangement is very convenient on locomotives, 
 as the cord can be drawn taut with one hand 
 while the diagram is taken with the other. 
 
 Make notes on the card of as many of the fol- 
 lowing- facts as possible: The day and hour of 
 taking- the diagram; the kind of engine from 
 which the diagram is taken, which end of the 
 cylinder and which engine, if one of a pair ; the 
 diameter of the cylinder, the leng-th of the stroke, 
 the diameter of the piston rod, the number of 
 revolutions per minute and the position of the 
 throttle; the atmospheric pressure; the steam 
 pressure at the boiler and at the engine, by the 
 g-aug-e ; the vacuum by the g-aug-e on condenser 
 and the temperature of the feed at the boiler; if 
 the engine is compound, the pressure in the re- 
 ceiver; the scale of the spring- used in the indi- 
 cator; the volume of the clearance at each end 
 of the cylinder, and what per cent of the piston 
 displacement each of these volumes is. (Direc- 
 tions for ascertaining- the volume of the clearance 
 and what per cent that volume is of the piston 
 displacement, are given on pag-es 97 to 100.) 
 
 It is often useful to make notes of special 
 circumstances of importance, such as a descrip- 
 tion of the boiler, the diameter and leng-th of the 
 steam and exhaust pipes, the temperature of the 
 feed water, the quantity of water consumed per 
 hour, etc. 
 
 On a locomotive, note the time of passag-e 
 between mile posts in minutes and seconds, 
 from which, when the diameter of the drivers is 
 known, the number of revolutions per minute 
 may be calculated. Note also the position of 
 the throttle and the link, the size of the blast 
 
STEAM ENGINE. 
 
 87 
 
 s 
 
 a ^ 
 
 i8 ^ 
 
 8 
 
 R 
 
 s; 
 g 
 
 .9 
 
 r ^> ^> 
 
 I 
 
 Co 
 
 'So 
 
 is " !: 
 
 $* r* r ^ O 
 
 ^ ,;2 rt <U *+- 
 
 1 '1 S c 
 
 rt > ^ v> 
 
 ? 1 1 1 
 
 1 1 1 1 S 
 
 5-i _i OJ S O 
 
 C C rt 
 
 cti rt 3 
 
 3 3 
 
 O 5 rt 
 
 ct 
 
 u 
 
 > rt ^ e 
 
 ^ ^ e 
 
 G V 
 
 be .2 
 
 .2 
 
 orifice, the weight of the train, and the gradient. 
 
 On diagrams from marine engines, note, in 
 
 addition to the general facts, the speed of the 
 
88 INDICATING THE 
 
 ship in knots per hour, the direction and force 
 of the wind, the direction and state of the sea, 
 the diameter and pitch of the screw, the kind of 
 coal, the amount consumed, and the ashes made 
 per hour. 
 
STEAM ENGINE. 89 
 
 CHAPTER V. 
 
 HOW TO FIND THE POWER OF AN ENGINE. 
 
 To find the power actually exerted within the 
 cylinder of a steam engine, it is necessary to 
 ascertain separately three factors and the product 
 of their continued multiplication. These factors 
 are: The net area of the piston, designated by 
 the letter a; the mean velocity or speed of the 
 piston, designated by 5; and the mean effective 
 pressure urging- the piston forward, desig-nated 
 by M. E. P. 
 
 The Piston Area. This, at the back end, is 
 the same as the area of cross-section of the cyl- 
 inder; at the crank end it is the same, less the 
 area of cross-section of the piston rod. These 
 areas may be found from their diameters in a 
 table of the areas of circles, or be computed by 
 multiplying- the square of the diameter in inches 
 by the approximate number 0.7854. 
 
 The Mean Piston Speed. The mean of the 
 constantly varying- speed of the piston is found 
 by multiplying- twice the leng-th of the stroke 
 measured in feet, by the number of revolutions 
 of the crank shaft per minute, which should be 
 carefully ascertained by taking- the mean of 
 many counting's, or the reading's of a speed 
 counter during- a considerable time. The mean 
 piston speed will be expressed in terms of feet 
 per minute. 
 
 7^he Mean Effective Pressure. There are 
 several approximate methods for computing- 
 the mean effective pressure, one of which is to 
 
90 
 
 INDICATING THB 
 
 divide the diagram into ten equal parts, as 
 shown in Fig*. 9. Then through the points of 
 division draw lines, which are called ordinates, 
 at right angles to the atmospheric line. The 
 mean heights or pressures of the small areas 
 thus formed are indicated by the dotted lines 
 midway between the ordinates. 
 
 The mean effective pressure of the whole (of 
 each) diagram may now be found by measuring 
 (on the dotted lines) the mean pressure in each 
 of the small areas with the scale corresponding 
 to the spring used in taking the diagram. 
 
 FIG. 9. 
 
 Diagrams from Hartford engine. Cylinder, 16X24 inches. Boiler pressure, 
 
 87 pounds. Vacuum per gauge, 23 l / 2 inches. 130 
 
 revolutions per minute. 
 
 The sum of these mean pressures, divided by 
 10, the number of divisions, will give the mean 
 effective pressure sought, in pounds per square 
 inch. 
 
 If a diagram has many irregularities of out- 
 line, it may be necessary to divide it into twenty 
 equal divisions to insure a correct measurement 
 of the pressures; in such a case we divide the 
 sum of the pressures by 20 instead of 10. In 
 
STEAM ENGINE. 
 
 91 
 
 other cases, when irregularities occur only in a 
 part of a diagram, it is only necessary to subdi- 
 vide one or more of the ten divisions to insure 
 greater accuracy in that part; in such case we 
 must measure the pressure in each subdivision 
 and divide their sum by 2 to get the mean press- 
 ure of that division. (See Fig. 11 for a full illus- 
 tration of this method.) 
 
 If the scale is not at hand the heights of the 
 divisions may be pricked or marked off on a strip 
 of paper, one after the other continuously until 
 all are measured; then the distance from the end 
 
 FIG. 10. 
 
 of the strip to the last mark will represent the 
 sum of all the measurements, which can be 
 measured in inches with an ordinary rule. This 
 quantity, divided by the number of divisions in 
 the diagram or diagrams, if there are two and 
 multiplied by the scale of the spring used, will 
 give the average of mean effective pressure, the 
 same as by the other method. 
 
 When there is a loop in the diagram, as in Fig. 
 10, the area inclosed in the loop should be sub- 
 tracted from the other part, as it represents loss 
 of efficiency. 
 
 The quickest and most accurate method for 
 
92 INDICATING THE 
 
 measuring' the diagram and finding the mean 
 effective pressure is by the use of Amsler's 
 Polar planimeter. With careful manipulation, 
 the planimeter will give the exact area of a 
 diagram in square inches and decimal parts 
 thereof, to hundredths of a square inch, and the 
 tedious process of dividing- the diagram into 
 equal parts and measuring their average press- 
 ures or heights, with the liability of making 
 errors, is avoided. 
 
 Measure the diagram with the planimeter, as 
 directed in Chapter VII. Divide the number of 
 square inches area thus found by the length of the 
 diagram, expressed in inches and decimals, and 
 the result will be the average heig"ht of the dia- 
 gram. Multiply this average height by the 
 scale corresponding to the spring used in taking 
 the diagrams, and the result will be the mean 
 effective pressure. It is better to multiply first 
 and divide afterward, to avoid troublesome frac- 
 tions. (A description of the planimeter and full 
 directions for its use on indicator diagrams are 
 given in Chapter VII, Part II, and Chapters X 
 and XI, Part III.) 
 
 Fig. 11 illustrates two diagrams divided first 
 into ten equal spaces, and then each end space 
 subdivided so as to more accurately measure 
 those parts of each in which the greatest irreg- 
 ularities occur. Observe that the pressures 
 or heights of the subdivisions of each end space 
 are measured, and the sum of these measure- 
 ments divided by 2 to get the mean pressure 
 or height of that one of the ten spaces. 
 
 The pressures of Diagram No. 1, as meas- 
 ured by the scale, are set in a column on the left, 
 
STEAM ENGINE. 
 
 93 
 
 DIAGRAM No. 1 
 Pressures. 
 
 DIAGRAM No. 2 
 Pressures. 
 
 FIG. 11. 
 
 HEIGHTS OF DIVISIONS MEASURED ON A STRIP OF PAPER. 
 DIAGRAM No. 1. DIAGRAM No. 2. 
 
 10)11.95 in. Divide by 10 10)11.93 in. 
 
 1.195 
 
 50 
 
 M.E.P. 59.750 
 
 Multiply by proper scale. 
 
 1.193 
 
 50 
 
 M. E. P. 59.650 
 
 PLANIMETER MEASUREMENTS. 
 
 DIAGRAM No. 1. DIAGRAM No. 2. 
 
 Square inches, 4.42 Square inches, 4.46 
 
 Length, 3.72 Length, 3.73 
 
 Average height, 1.188 Average height, 1.195 
 
 M. E. P. 59.4 Ibs. M. E. P. 59.75 Ibs. 
 
94 INDICATING THE 
 
 while those of No. 2 are set in a column on the 
 right. The sum of each column divided by 10 
 gives the M. E. P. of that diagram. 
 
 The heights of Diagram No. 1, marked off on 
 a slip of paper continuously, measure 11.93 
 inches, while those of No. 2 measure 11.95 
 inches; these quantities, divided by 10 and mul- 
 tiplied by 50, give the M. E. P. of each diagram 
 respectively, and if accurately measured, will 
 be the same as found by the scale. 
 
 These diagrams, when measured by the 
 planimeter, give results which are substantially 
 the same as found by the approximate methods. 
 These results are given at the bottom of page 
 93 with Fig. 11. 
 
 Having now obtained, by one of the several 
 methods given above, our three factors men- 
 tioned at the beginning of this chapter, viz.: 
 
 a = mean net area of piston in square inches. 
 
 5 = mean speed of piston in feet per minute. 
 
 p = mean effective pressure in pounds on 
 each square inch of the piston the product of 
 their continued multiplication will give the indi- 
 cated power of the engine in foot-pounds per 
 minute; and this product divided by 33,000, 
 which is the conventional number of foot-pounds 
 in one horse power, will give a quotient equal to 
 the indicated power of the engine in indicated 
 horse power, commonly designated by the initial 
 letters I. H. P. 
 
 Thus : I. H. P. = ^X_X/ or as P 
 33,000 33.. 000 
 
 When there are a number of diagrams taken 
 from the same engine to be worked up, the cal- 
 culations may be simplified by multiplying the 
 
STEAM ENGINE. 95 
 
 area of the piston by twice the length of the 
 stroke, and dividing- the result by 33,000. This 
 gives the "constant of the engine," that is, the 
 power that would be developed at one revolution 
 per minute with one pound mean effective press- 
 ure. Multiply this constant by the number of 
 revolutions per minute, and then by the mean 
 effective pressure, and the product will be the 
 I. H. P. 
 
 If the number of revolutions is the same for 
 several diagrams, as is frequently the case with 
 stationary engines, the calculation may be still 
 further simplified by multiplying 1 the "constant 
 of the engine" by the number of revolutions 
 per minute. This will give the "horse power 
 constant, " or the horse power developed per 
 pound M. YJ. P. Multiply the horse power 
 constant by the M. E. P., and the product will 
 be the indicated horse power (I. H. P.). 
 
96 INDICATING THK 
 
 CHAPTER VI. 
 
 THE HYPERBOLIC CURVE. 
 
 This curve is frequently applied to indicator 
 diagrams for the purpose of comparing- it with 
 the expansion curve as drawn by the indicator, 
 and if it coincides very nearly, this fact may 
 generally be taken as evidence tending- to show 
 that the steam and exhaust valves of the engine 
 are properly closed and the piston tight. 
 
 Without going into any discussion regarding 
 condensation and re-evaporation in steam engine 
 cylinders, it is a well known fact that indicator 
 diagrams, taken from large engines, properly 
 made and in good order, show expansion curves 
 which are close approximations to the hyperbola. 
 
 Before this curve can be drawn, it is neces- 
 sary to ascertain the capacity of the clearance or 
 waste room; that is, all the space between the 
 cylinder heads and the piston at each dead cen- 
 ter, including the counterbore and the ports up 
 to the face of the closed valves. 
 
 There are several ways of finding this: One, 
 by direct calculation from sectional drawings, 
 when accurate drawings can be obtained; 
 another, by putting the engine at dead center 
 with valves closed, and then filling the clearance 
 space with water, which has been carefully 
 weighed in a convenient vessel, then weighing 
 what is left; and the difference between the 
 weight of the whole and the remainder is the 
 weight of water required to fill the clearance 
 space. From this the number of cubic inches 
 
STKAM KNGINE. 97 
 
 occupied by the water may be computed. At 
 ordinary temperatures (60 to 75 F.), for all 
 practical purposes, we may call the weight of 
 one cubic inch of water 0.036 pounds, and 27.8 
 cubic inches of water equal to one pound. 
 Then the number of pounds of water, divided 
 by 0.036 or multiplied by 27.8, will give the 
 number of cubic inches. If accurate scales for 
 weig-hing- the water are not at hand, it can be 
 carefully measured in a quart or pint measure, 
 and the number of cubic inches found directly. 
 A g-allon contains 231 cubic inches, a quart 57.75 
 and a pint 28.875 cubic inches. 
 
 The volume of the clearance will rarely be 
 alike at the two ends of the cylinder, therefore 
 the number of cubic inches in the clearance at 
 each end must be divided by the net area of the 
 piston at its own end; that is, the number of 
 cubic inches in the clearance at the end nearest 
 the crank must be divided by the number of 
 square inches in the cross-section of the cyl- 
 inder, less the number of square inches in the 
 cross-section of the piston-rod; and the number 
 of cubic inches in the clearance at the end 
 farthest from the crank must be divided by 
 the number of square inches in the cross-section 
 of the cylinder. The quotient in each case will 
 be the leng-th of clearance at the respective ends 
 of the cylinder, expressed in inches. 
 
 It is convenient to have the leng-th of the 
 clearance expressed as a fraction of the piston 
 displacement or stroke of the piston. To ob- 
 tain this fraction, divide the number of cubic 
 inches in volume of clearance by the number of 
 cubic inches in the volume swept through by the 
 
98 INDICATING THE 
 
 piston at each end separately, taking* care to 
 allow for the volume occupied at one end by the 
 piston rod, and the quotient will be the decimal 
 fraction that the clearance space is of the volume 
 swept throug-h by the piston. In this instance 
 (Fig-. 12) it is found to be .16 inches. 
 
 Fig 1 . 12 illustrates a g"ood method for locating- 
 points in the hyperbola throug-h which the curve 
 may be drawn. 
 
 First, draw the zero line V, at the proper 
 
 Id -- v -- V- _^__ -- \i __ \f __ L _ 
 
 U - -- ^Length of2jta.gro.7n 3.90 
 FiG. 12. 
 
 distance, viz., 14-jV pounds by the scale below 
 and parallel with the atmospheric line; next, 
 draw the clearance line O, as computed, .16 of 
 an inch from the end of the diagram; next, locate 
 the point of cut-off X, and draw the perpen- 
 dicular line number 3 through it; next, divide 
 the space between this line and the clearance 
 line into three equal parts; then, taking- one of 
 these parts for a measure, point off, on the 
 vacuum line, equal spaces toward the left hand 
 until one or more falls beyond the end of the 
 
STEAM ENGINE. 99 
 
 diagram as shown, and erect perpendicular lines 
 from each point. These lines are called ordioates 
 and numbered consecutively 1, 2, 3, 4, etc., 
 beginning- with the one next to the clearance 
 line. It is well to bear in mind the fact that 
 vertical distance on a diagram represents press- 
 ure, and horizontal distance volume. 
 
 In this case we have started the hyperbola 
 from the point of cut-off X, and its course is 
 indicated by the short lines drawn throug-h the 
 ordinates a little above the actual curve, with 
 their calculated pressures written above; the 
 actual pressures of the expansion curve are 
 written below it. The properties of the hyper- 
 bola are such, that if the distance of the point 
 Jf from the clearance line O be multiplied by the 
 heig-ht of X from the zero line V, the heig-ht of 
 any other point in the curve can be found by 
 dividing- this product by its distance from the 
 clearance line. And on this principle we proceed 
 to locate points on the ordinates throug-h which 
 our hyperbola will run. 
 
 We find the pressure at the point of cut-off 
 to be 121 pounds, with a volume which we call 
 3, because there are three spaces or volumes 
 between it and the clearance line. Then, 121 X 
 3 = 363, which is our dividend for all the other 
 volumes. Therefore the height at which the 
 hyperbola will cut ordinate 4 will be determined 
 by dividing- 363 by 4, which is 90.8 (it is un- 
 necessary to carry the division beyond one deci- 
 mal), and of ordinate 5, 72.6; of ordinate 6, 60.5; 
 and so on to the end. At ordinate 12 we find 
 that the hyperbolic and the actual curves practi- 
 cally coincide. In like manner we may extend 
 
100 INDICATING THE 
 
 the curve to the right: 363 -*- 2 = 181 pounds, 
 which would be the pressure if the steam were 
 compressed up to two volumes. If desired, 
 the hyperbolic curve can be started just before 
 the point of release, and projected in the op- 
 posite direction by the same method. 
 
 Instead of using- figures, which stand for 
 pressures or volumes of steam, to locate the 
 hyperbola, as in this instance, the distances 
 from the base and perpendicular lines of any 
 point may be expressed in inches and decimal 
 parts, with the same result. 
 
 A quick way to draw the hyperbola is to take 
 the whole distance between ordinate 3 and the 
 clearance line as a measure, and set off equal 
 spaces to the left, as before directed. Then we 
 would have but four ordinates, and would num- 
 ber them as follows: 1 at 3d, 2 at 6th, 3 at 9th 
 and 4 at 12th. At 1 we would have a pressure 
 of 121 pounds; at 2, 121 pounds -*- 2 = 60.5; at 3, 
 121 pounds -* 3 = 40; and at 4, 121 pounds * 4 
 = 30. 
 
 As a general rule, the near approximation of 
 the expansion curve to the theoretical or hyper- 
 bolic curve may be taken as evidence of good 
 conditions, but should not be accepted for a cer- 
 tainty, unless all the known facts and conditions 
 tend in the same direction. 
 
 GEOMETRIC METHOD OF FINDING THE HYPERBOLA. 
 
 The hyperbola may be found by following 
 the directions given below, in connection with 
 Fig. 13. A is the atmospheric line; Zthe zero 
 line, or line of no pressure; B the line of boiler 
 pressure, and C the clearance line. Locate the 
 
STEAM ENGINE. 
 
 101 
 
 first point in the hyperbola at the point of release, 
 X, and draw the vertical line, X E. Then draw 
 diagonal line EH; then, from X, draw horizontal 
 
 FIG. 13. 
 
 line 5 to its intersection with EH, through which 
 draw vertical line, F O. Now, mark off points 
 between and E, as 1, 2, 3, 4 exact spacing is 
 unnecessary and from these points draw di- 
 agonal lines to H, and vertical lines down to, or 
 
 ^-^. <L'. ^S.r^_ne_ , 
 
 FIG. 14. 
 
 a little below, the actual curve. Now, draw 
 horizontal lines 6, 7, 8 and 9 from the points of 
 intersection in the line F O, of the diagonal lines 
 
102 INDICATING THE 
 
 H 4, HZ, H2 and 77 1, respectively; and the 
 points where these lines cross the vertical lines, 
 1, 2, 3 and 4, in connection with points Jf and (9, 
 are the points throug-h which the hyperbola 
 should be drawn, as shown b^ the dotted curve. 
 
 ANOTHER METHOD OF FINDING THE HYPERBOLA. 
 
 Fig". 14, shown on preceding" pag-e, illustrates 
 another method of finding- the hyperbola. 
 
 Through the point of release b draw any line, 
 as a B, and make A B equal to a b. Then draw 
 any other line, as cD, and make cd equal to A D ; 
 then d will be a point in the hyperbola passing- 
 from b to A, as shown by the dotted curve. By 
 drawing- a number of lines throug-h A and fol- 
 lowing- the same method, we can find as many 
 points in the hyperbola. 
 
STKAM ENGINE. 103 
 
 CHAPTER VII. 
 
 AMSLER'S POLAR PLANIMETER, WITH DIRECTIONS 
 
 FOR USING IT ON INDICATOR DIAGRAMS. 
 Fig-. 15 represents the No. 1 planimeter. It 
 is the simplest form of the instrument, having 
 but one wheel, and is designed to measure 
 areas in square inches and decimals of a square 
 inch. The figures on the roller wheel D repre- 
 sent units, the graduations on the wheel repre- 
 sent tenths, and the vernier gives the hundredths. 
 
 FIG. 15. 
 
 Directions for Measuring an Indicator Dia- 
 gram with a No. i Planimeter. Care should be 
 taken to have a flat, even, unglazed surface for 
 the roller wheel to travel upon. A sheet of dull 
 finished cardboard serves the purpose very well. 
 
 Set the weight in position on the pivot end of 
 the bar P, and after placing the instrument and 
 the diagram in about the position shown in the 
 cut (Fig. 16), press down the needle point so 
 that it will hold its place; set the tracer point at 
 any given point in the outline of the diagram, as 
 at jF, and adjust the roller wheel to zero. Now 
 follow the outline of the diagram carefully with 
 the tracer point, moving it in the direction indi- 
 cated by the arrow, or that of the hands of a 
 
104 
 
 INDICATING THE 
 
 watch, until it returns to the point of beginning-. 
 The result may then be read as follows: Suppose 
 we find that the largest figure on the roller 
 wheel D that has passed by zero on the vernier 
 E, to be 2 (units), and the number of gradua- 
 tions that have also passed zero on the vernier to 
 be 4 (tenths), and the number of the graduation 
 on the vernier which exactlv coincides with a 
 
 FIG. 16. 
 
 graduation on the wheel to be 8 (hundredths), 
 then we have 2.48 square inches as the area of 
 the diagram. Divide this by the length of the 
 diagram, which we will call 3 inches, and we 
 have .8266 inches as the average height of the 
 diagram. Multiply this by the scale of the spring 
 used in taking the diagram, which in this case is 
 40, and we Have 33.06 pounds as the mean effect- 
 ive pressure per square inch on the piston of the 
 engine. 
 
STEAM ENGINE. 105 
 
 When there is a loop in the diagram (see Fig-. 
 10), caused by the steam expanding below the 
 back pressure line when the engine is non-con- 
 densing-, its outline should be traced in the same 
 way as directed for a plain diagram, as the prin- 
 ciple on which the planimeter works is such that 
 the area of the loop will be subtracted from the 
 main part of the diagram, and the reading of the 
 instrument when the measurement is completed 
 will be the correct net area sought. 
 
 When one has become familiar with the use 
 of the planimeter it is not necessary always to 
 set the wheels at zero, as required in the forego- 
 ing directions, but their reading as they stand 
 just before beginning to trace a diagram may 
 be noted down, and this quantity subtracted 
 from the reading when the tracing is completed. 
 The difference between the two readings is 
 the area sought. 
 
 The use of Amsler's Polar planimeter in the 
 measurement of indicator diagrams enables one 
 to measure ten cards with it in the time which 
 would be required to measure one card by any 
 other method, and it insures the utmost accu- 
 racy in the work. 
 
 The planimeter is a precise and delicate in- 
 strument, and should be handled and kept with 
 great care, in order that it may be depended 
 upon to give correct results. After using it 
 should be wiped clean with a piece of soft 
 chamois skin. 
 
 (8) 
 
INDICATING 
 
 THE 
 
 REFRIGERATING MACHINE 
 
 PART III. 
 CONSTRUCTION OF INDICATORS. 
 
 INTRODUCTION. 
 
 MANUFACTURERS' DESCRIPTION OF INDICATORS, 
 
 PLANIMETERS, REDUCING WHEELS AND COF- 
 FIN *S AVERAGING INSTRUMENT, ETC. 
 
 The author is indebted to the various indi- 
 cator manufacturers for the following" cuts and 
 descriptions of their instruments. The indi- 
 cators are described as "Steam Engine Indi- 
 cators," but the descriptions, of course, apply 
 equally as well to ammonia compressor indica- 
 tors, the only difference being- that for com- 
 pressor indicating- most manufacturers make an 
 indicator of steel, aluminum or composition 
 metal, to resist the action of ammonia. In all 
 other particulars the indicators are the same. 
 
 I recommend that the reader send for the 
 catalogues and price lists of these instruments. 
 
 The catalog-ues will be mailed free of charg-e, 
 and many of them are quite valuable as treatises 
 on indicator practice. 
 
 107 
 
108 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER I. 
 
 THE CROSBY INDICATOR. 
 
 The Crosby Indicator is designed and con- 
 structed to meet the exacting- requirements of 
 modern engineering-. During- the last few years, 
 under the keen search and exhaustive tests 
 of eminent engineers, the practice in this de- 
 partment of science has underg-one important 
 chang-es, tending- to establish more correct meth- 
 ods and thereby to reach more accurate results; 
 especially is this true in the use and scope of the 
 indicator, so that the work done with this instru- 
 ment in former times seems coarse and crude 
 when compared with the more exact attainment 
 of the present. 
 
 Educators in the scientific schools of both 
 Europe and America have seen the importance 
 of more exact knowledg-e and instruction in the 
 technical sciences; and the great achievements 
 of recent years in the construction of building's, 
 ships, armaments and machines attest the thor- 
 oughness with which research in these depart- 
 ments has been prosecuted ; in none has there 
 been greater progress made than in those of 
 mechanical and steam engineering-. 
 
 A knowledg-e of these facts has kept the manu- 
 facturer of the steam engine and ammonia com- 
 pressor indicator on the alert. Within a recent 
 time, the Crosby indicator has, without any great 
 change in its outward appearance, received im- 
 portant improvements. Slight changes in design, 
 a more perfect mechanical construction due to the 
 
CONSTRUCTION OF INDICATORS. 
 
 109 
 
 use of improved and specialized machinery, and a 
 careful selection of metals for the different parts, 
 have all contributed to this favorable result. 
 
 The movements of piston and pencil point are 
 perfectly parallel; the movement of the pencil 
 point is also exactly parallel with the axis of the 
 drum. 
 
 FIG. 1. 
 
 The rating- of the springs by the newly con- 
 structed testing- apparatus, which embodies all 
 the valuable aids to exactness which have yet 
 been discovered, is nearer perfection than could 
 have been attained, or even expected, until within 
 a very recent time. 
 
 DKSCRIPTION OF THE INDICATOR. 
 
 The illustration shows the design and 
 
110 CONSTRUCTION OP^ INDICATORS. 
 
 arrangement of the parts of the Crosby steam 
 engine indicator. 
 
 Part 4 is the cylinder proper, in which the 
 movement of the piston takes place. It is made 
 of a special alloy, exactly suited to the varying 
 temperatures to which it is subjected, and se- 
 cures to the piston the same freedom of move- 
 ment with high pressure steam as with low ; and 
 as its bottom end is free and out of contact with 
 all other parts, its longitudinal expansion or con- 
 traction is unimpeded, and no distortion can pos- 
 sibly take place. 
 
 Between parts 4 and 5 is an annular chamber, 
 which serves as a steam jacket; and being- open 
 at the bottom, can hold no water, but will always 
 be filled with steam of nearly the same tempera- 
 ture as that in the cylinder. 
 
 The piston 8 is formed from a solid piece of 
 the finest tool steel. Its shell is made as thin as 
 possible consistent with proper streng-th. It is 
 hardened to prevent any reduction of its area 
 by wearing-, then ground and lapped to fit (to the 
 ten-thousandth part of an inch) a cylindrical 
 gauge of standard size. Shallow channels in its 
 outer surface provide a steam packing, and the 
 moisture and oil which they retain act as lubri- 
 cants, and prevent undue leakage by the piston. 
 
 The piston rod 10 is of steel and is made hol- 
 low for lightness. It is connected with the piston 
 by a screw at its .lower end. When these parts 
 are connected, be sure to screw the rod into the 
 slotted socket as far as it will go; that is until 
 the upper edge of the socket is set firmly against 
 the bottom of the channel formed in the under 
 side of the shoulder of the piston rod. This is 
 
CONSTRUCTION OF INDICATORS. Ill 
 
 very important, as it insures a correct alinement 
 of the parts and a free movement of the piston 
 within the cylinder. 
 
 The swivel head 12 is screwed into the upper 
 end of the piston rod, more or less according- to 
 the required height of the atmospheric line on 
 the diagram. Its head is pivoted to the piston 
 rod link of the pencil mechanism. 
 
 The cap 2 rests on top of the cylinder, and 
 holds the sleeve and all connected parts in place. 
 The smooth portion of the cap which fits into the 
 top of the cylinder serves as a guide by which all 
 the moving parts are adjusted and kept in correct 
 alinement. 
 
 The sleeve 3 surrounds the upper part of the 
 cylinder and supports the pencil mechanism. 
 The arm X is an integral part of it. The handle 
 for adjusting the pencil point is threaded through 
 the arm, and in contact with a stop screw in the 
 plate may be delicately adjusted to the surface 
 of the paper on the drum. It is made of hard 
 wood in two sections ; the inner one may be used 
 as a lock nut to maintain the adjustment. 
 
 The pencil mechanism is designed to afford 
 sufficient strength and steadiness of movement, 
 with the utmost lightness ; thereby eliminating, 
 as far as possible, the effect of momentum, which 
 is especially troublesome in high speed work. 
 Its fundamental kinematic principle is that of 
 the pantograph. The fulcrum of the mechanism 
 as a whole, the point attached to the piston rod 
 and the pencil point are always in a straight line. 
 This gives to the pencil point a movement ex- 
 actly parallel with that of the piston. The pencil 
 lever, links and pins are all made of hardened 
 
112 CONSTRUCTION OF INDICATORS. 
 
 steel; the latter slightly tapering" are ground 
 and lapped to fit accurately, without perceptible 
 friction or lost motion. 
 
 Springs. In order to obtain a correct dia- 
 gram, the height of the pencil of the indicator 
 must exactly represent in pounds 
 per square inch the pressure on 
 the piston of the steam engine at 
 every point of the stroke ; and the 
 velocity of the surface of the 
 drum must bear at every instant 
 a constant ratio to the velocity 
 of the piston. These two essen- 
 tial conditions have been attained 
 to a great degree of exactness in 
 the Crosby indicator by a very 
 ingenious construction and nice 
 adaptation of both its piston and 
 drum springs, and have proved satisfactory. 
 
 The piston spring is of unique and ingenious 
 design, being made of a single piece of the finest 
 spring steel wire, wound from the middle into a 
 double coil, the spiral ends of which are screwed 
 into a brass head having four radial wings with 
 spirally drilled holes to receive and hold them 
 securely in place. Ad j ustment is made by screw- 
 ing them into the head more or less until exactly 
 the right strength of spring is obtained, when 
 they are there firmly fixed. This method of 
 fastening and adjusting removes all danger of 
 loosening coils, and obviates all necessity for 
 grinding the wires. 
 
 The foot of the spring in which lightness is 
 of great importance, it being the part subject to 
 the greatest movement is a small steel bead, 
 
CONSTRUCTION OF INDICATORS. 113 
 
 firmly "staked" on to the wire. This takes the 
 place of the heavy brass foot used in other indi- 
 cators, and reduces the inertia and momentum 
 at this point to a minimum, whereby a great im- 
 provement is effected. This bead has its bearing 
 in the center of the piston, and in connection with 
 the lower end of the piston rod and the upper end 
 of the piston screw (both of which are concaved 
 to fit) it forms a ball-and-socket joint which 
 allows the spring- to yield to pressure from any 
 direction without causing- the piston to bind in 
 the cylinder. 
 
 The drum spring- in the Crosby indicator is 
 a short spiral. 
 
 If the conditions under which the drum spring- 
 operates be considered, it will readily be seen that 
 at the beginning- of the stroke, when the cord hss 
 all the resistance of the drum and spring- to over- 
 come, the spring 1 should offer less resistance than 
 at any other time ; in the beginning- of the stroke 
 in the opposite direction, however, when the 
 spring has to overcome the inertia and friction of 
 the drum, its energy or recoil should be greatest. 
 
 These conditions are fully met in the Crosby 
 indicator; its drum spring being a short spiral, 
 having no friction, a quick recoil, and being sci- 
 entifically proportioned to the work it has to do. 
 
 The drum and its appurtenances, except the 
 drum spring, are similar in design and function 
 to like parts of other indicators, and need not be 
 particularly described. All the moving parts 
 are designed to secure sufficient strength with 
 the utmost lightness, by which the effect of in- 
 ertia and momentum is reduced to the least pos- 
 sible amount. 
 
114 CONSTRUCTION OF INDICATORS. 
 
 From the design of the Crosby indicator as 
 above set forth the conformation and purpose 
 of its several parts it will be seen that every 
 opportunity to improve the instrument has been 
 taken. Add to this the fact that only the most 
 skillful workmen of long- training- in the art are 
 employed, and that every part is made to a stand- 
 ard size by modern specialized machinery, with 
 tools perfectly adapted to their work, and it will 
 be admitted that the proper means have been 
 taken to produce a first-class indicator. We be- 
 lieve this object has been accomplished. 
 
 All Crosby indicators are chang-eable from 
 rig-fat hand to left hand instruments if occasion 
 requires. 
 
 The Crosby indicator is ordinarily made with 
 a drum one and one-half inches in diameter, this 
 being- the correct size for hig-h speed work, and 
 answering- equally well for low speeds. If, how- 
 ever, the indicator is to be used only for low 
 speeds, and a long-er diagram is preferred, it can 
 be furnished with a 2-inch drum. 
 
 The Crosby indicator in a special design is 
 made to indicate extremely hig-h pressures. In- 
 struments of this desig-n have been used with 
 perfect success in the testing- of ordnance and 
 for other explosive effects. 
 
 When desired the Crosby indicator is made 
 of steel, to resist the action of ammonia. 
 
 A detent attachment is furnished with the 
 instrument when required. 
 
 Every part of the Crosby indicator is per- 
 fectly adapted to its particular function, also to 
 its relation to all the other parts, in size, pro- 
 portion and material. Its small size and lig-ht 
 
CONSTRUCTION OF INDICATORS. 115 
 
 weight serve to protect it from accident, and so 
 contribute to its durability and to the facility 
 with which it can be handled. 
 
 Full particulars for the proper care and hand- 
 ling- of the Crosby indicator accompany each in- 
 strument. They are manufactured only by the 
 Crosby Steam Gage and Valve Co., Boston, Mass. 
 
116 
 
 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER II. 
 
 THE BACHELDER ADJUSTABLE SPRING INDICATOR. 
 
 Since the introduction of the Bachelder indi- 
 cator to the pub- 
 lic some years ago 
 it has been mate- 
 rially improved, 
 both in design and 
 detail of construc- 
 tion. 
 
 The flat spring- 
 is no longer an ex- 
 periment, but an 
 established suc- 
 cess as to accu- 
 racy and durabil- 
 
 FIG. 
 
 ity. The downward motion of the spring- being 
 the same as the upward, a correct record is 
 shown of a condensing or low pressure cylinder 
 of a compound engine. 
 
 DESCRIPTION OF THE INDICATOR. 
 
 The special features of this instrument con- 
 sist of the T shaped hollow case, and adjustable 
 flat spring. The cylinder, being separate from 
 the case proper, is screwed to the lower end, 
 where it is held by a small set screw. By turn- 
 ing this screw one-half of a turn the-cylinder can 
 be unscrewed; then to remove the piston, take 
 out the screw at the piston end of the spring, 
 and at the connection with pencil lever. These 
 are the only parts necessary to remove for 
 cleaning. The flat steel spring works in the 
 
CONSTRUCTION OF INDICATORS. 117 
 
 horizontal body of the case, one end being- 
 rig-idly secured by means of a taper steel screw, 
 and the other attached to the connecting- rod be- 
 tween the piston and pencil lever. The chang-e 
 of spring- is made by removing- the screw that 
 connects it to the piston rod, and the one which 
 holds it in the case. The rang-e of the hig-h 
 pressure spring- is so great that a chang-e is only 
 necessary when using- on a compound or triple 
 
 FiG. 4. 
 
 expansion eng-ine. Connection is made to the 
 piston with a ball and socket joint. Access can 
 be had to the piston for oiling- or removing-, by 
 unscrewing- knurled cap on face of instrument. 
 
 A split bushing- in the case is provided with a 
 longitudinal recess for the reception of the 
 spring-. In the upper side of the bushing- a hard- 
 ened steel pin is inserted. The lower side of the 
 case has a longitudinal slot, through which a set 
 screw passes and throug-h the lower side of the 
 
118 CONSTRUCTION OF INDICATORS. 
 
 bushing, directly opposite the steel pin, so that 
 when the screw is tightened, the spring is held 
 rigidly between it and the steel pin. To change 
 from one scale to another, loosen the set screw 
 and slide the bushing along until the mark on 
 projecting block is opposite the scale required, 
 then tighten the screw. The scales are marked 
 on the face of the case, the upper one being for 
 high pressure, and the other for low pressure. 
 The parallel motion is of the latest improved 
 design, is entirely accurate and free from lost 
 motion or friction. The height of atmospheric 
 line is adjustable by means of a swivel in connect- 
 ing rod near the pencil lever. With this brief 
 description and a reference to the accompanying 
 cuts, the general principle will be readily under- 
 stood. 
 
 Each indicator is furnished with two flat 
 springs, which are equivalent to eleven spiral 
 springs. 
 
 The low pressure springs have the scales of 
 10, 15, 20 and 25. The high pressure springs 
 have the scales of 30, 40, 50, 60, 70, 80 and 90, so 
 that cards of proper height can be taken at any 
 pressure up to 175 pounds. A special instru- 
 ment for ammonia use, or for higher pressures 
 than the above is furnished when required. 
 
 The Bachelder indicator is manufactured 
 only by John S. Bushnell, successor to Thomp- 
 son & Bushnell,- 120 and 122 Liberty street, 
 New York City. 
 
CONSTRUCTION OF INDICATORS. 119 
 
 CHAPTER III. 
 
 IMPROVED ROBERTSON-THOMPSON INDICATOR. 
 
 The improved Robertson-Thompson indica- 
 tor, which has just been placed on the market, is 
 unusually heavy, but as a result of most careful 
 experiment this weight is so perfectly distribu- 
 ted that the best results may be attained at 
 speeds far in excess of any met with in actual 
 practice. One of the most serious errors in or- 
 dinary indicator work is caused by flexure of 
 the arm which carries the drum, particularly 
 when the cord is carried above or below the in- 
 strument. In this manner an error of 10 per 
 cent is easily possible, particularly if the instru- 
 ment is being- used with a high pressure spring. 
 For instance, with an 80 spring- it would re- 
 quire a movement of but one-eightieth of an inch 
 to show an error of one pound. In many cases 
 weakness at this point will account for the curi- 
 ous features often noticed at the junction of the 
 admission and steam lines on the diagram. The 
 drum carrying arm of the improved Robertson- 
 Thompson indicator is so stiff that no error from 
 this cause is possible. 
 
 DESCRIPTION OF THE INDICATOR. 
 
 The cylinder is steam jacketed, and by its 
 construction the possibility of the piston being 
 cramped as a result of external strains is pre- 
 cluded. The area of this cylinder is exactly 
 one-half inch, and each spring is suitable for 
 twice the pressure stamped on it; for instance, 
 a 60 spring may be used for a pressure of 120 
 
120 
 
 CONSTRUCTION OF INDICATORS. 
 
 pounds or less. The coupling" is reamed to % -inch 
 area, and with each instrument an extra ^-inch 
 piston is furnished. With this piston each spring 
 may be used for pressures four times as great as 
 the number stampthereon, so that with a60spring- 
 240 pounds may be safely indicated. This extra 
 piston is of special value for hydraulic and g-as en- 
 g-ine work. The pistons are made of steel, but 
 phosphor bronze will be substituted if preferred. 
 
 FIG. 5. 
 
 The piston spring's are standardized by the most 
 approved testing- apparatus, in connection with 
 a mercury column. To guarantee against press- 
 ure above the piston, a large relief opening has 
 been provided, the outlet being- a neat swivel 
 elbow, by means of which the "blow" may be 
 discharged in any direction, at the will of the 
 operator. Each instrument is provided with a 
 detent or stop motion. 
 
 In Fig. 6 a new device is shown for adjusting- 
 
CONSTRUCTION OF INDICATORS. 
 
 121 
 
 the tension of the drum spring 1 . 
 By rotating- the knurled head 
 S, to the rig-lit the spring- may 
 be tightened as much as de- 
 sired, and securely held by 
 pawl P; the ratchet wheel N 
 is securely attached to the shaft 
 by means of a left hand thread. 
 FIG. 6. Thus the tendency of the drum 
 
 spring- is to tighten the ratchet nut more firmly. 
 By pressing- the thumb into the recess in the 
 spring- winder S, the pawl is released, when the 
 tension maybe diminished to any desired amount. 
 This ratchet wheel has sixteen teeth, which pro- 
 vide for the adjustment of the spring to a nicety. 
 Drum springs are of the clock type, but spiral 
 form will be furnished if preferred. Cone bear- 
 ings are provided to take up all wear of the drum 
 spindle. The parallel movement is made of tool 
 steel, highly polished and richly blued. All 
 bearings are wide and perfectly fitted. 
 
 In Fig. 7 the pencil mechanism is shown in 
 three positions, which will give a perfect idea 
 of the manner in which an absolutely correct 
 straight line is obtained. This movement forms 
 a perfect pantograph, 
 so that the pencil move- 
 ment is exactly propor- 
 tional to that of the pis- 
 ton, theratiobeing5tol. 
 All moving parts are 
 worked down to the lightest weight consistent 
 with durability. For comparison it may be stated 
 that the drum weight is but one and one-fourth 
 ounces, and the pencil lever twenty-five grains. 
 
 (9) 
 
 FIG. 
 
122 CONSTRUCTION OF INDICATORS. 
 
 By special order, the instrument will be fitted 
 with the improved Victor reducing- wheel, which 
 comprises a patent cord feeding- device. The 
 manufacturers are James L. Robertson & Sons, 
 No. 204 Fulton street, New York city. 
 
CONSTRUCTION OF INDICATORS. 123 
 
 CHAPTER IV. 
 
 THE BUFFALO INDICATOR. 
 
 The Buffalo indicator is of standard size, and 
 well made throughout. It is handsome in design 
 and finish, all working- parts being- accurately 
 fitted and carefully tested. The working- parts 
 are few, and of such light weight that a quick re- 
 sponse to the steam pressure is always insured. 
 A new style double coil spring of high tension 
 is used, which insures correct diagrams. The 
 piston is ^2-inch area, provided with 
 water grooves. The piston rod is 
 made of r Vmch steel, 
 hollow at the upper end, 
 threaded to receive a 
 swivel head (which per- 
 mits of the adjustment of 
 the pencil to suit weak or 
 strong vacuum springs), 
 and turned smaller at the 
 lower, to reduce its weight. 
 
 The parallel motion is sms^* p IG< 8 . 
 secured by a link attached to and governing the 
 pencil lever direct. The screws of this link are 
 made free from any appreciable loss motion, and 
 will remain so indefinitely. It is made of "tool 
 steel," and will trace a correct vertical line within 
 its limit of three inches. The arm, link and up- 
 rights are made of r \ X ^-inch steel, the uprights 
 being held together by small bars /^-inch diam- 
 eter, one-half inch long, the ends of which are 
 turned smaller, and threaded to receive the ^-i 
 
124 
 
 CONSTRUCTION OF INDICATORS. 
 
 hex nut, which fastens the uprights against the 
 shoulder. The lower bar is centered at the 
 proper angle to fit the pivot screws, and permit 
 of very fine adjustment. Bearings of the link are 
 one-fourth inch long. The entire movement is 
 carefully blued. The movement of the pencil 
 coincides with that of the piston at all times, and 
 is acknowledged to be the most accurate made. 
 The rosewood handle that swings the pencil 
 
 FIG. 9. 
 
 movement can be screwed in or out against the 
 stop post so as to get the required pressure of 
 lead or wire upon the card. 
 
 For ordinary use, drums 1.75 inches diam- 
 eter, three and one-half inches high two inches 
 when specified are furnished. They are made 
 from special drawn telescope tubing, turned as 
 thin as is consistent with ordinary usage, and 
 supported at the top by a bearing one-half inch 
 long. The barrel, which carries the drum, it will 
 be noticed by reference to the cut, is very light, 
 
CONSTRUCTION OF INDICATORS. 125 
 
 and is provided with adjustable cone bearings. 
 The drum spring- is a flat coil of the clock pattern, 
 and can be adjusted for any speed met in prac- 
 tice, by unscrewing- the thumb screw, turning- to 
 the quarter, then tighten as shown. The arm 
 which carries the g-uide pulleys can be adjusted 
 to allow the cord to run in any direction without 
 the aid of carrying- pulleys. The drum cord 
 will not climb from one coil to another, and can 
 be adjusted to any angle by means of the g-uide 
 pulleys. 
 
 The indicator is made almost entirely of 
 brass, highly polished and nickeled; but for am- 
 monia a special composition is used. Each in- 
 dicator is sent out in a polished mahogany box, 
 fitted with a metal plate, to which the indicator 
 is attached by means of the coupling and plug. 
 
126 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER V. 
 
 AMERICAN THOMPSON INDICATOR. 
 
 The American Thompson improved indi- 
 cator was patented by J. W. Thompson, August 
 31, 1875, and July 12, 1881. 
 
 The radical improvements, as made in the old 
 style Thompson indicator, consist of lightening 
 the moving parts, substituting steel screws in 
 place of taper pins, using a very light steel link 
 instead of a large brass one, reducing the weight 
 of the pencil lever, also weight of squares on 
 trunk of piston and lock nut on end of spindle, 
 and increasing the bearing on connection of par- 
 allel motion. By shortening the length and re- 
 ducing the actual weight of the paper cylinder 
 just one-half, and by shortening the bearing on 
 spindle, also lowering the spring casing to a 
 nearer plane to that in which the cord runs, we 
 have reduced the momentum of the paper cylin- 
 der to a very small amount. All of these im- 
 provements have lessened the amount of friction, 
 which was heretofore very small, but is now 
 reduced to a minimum. 
 
 The parallel movement of pencil is secured 
 by a link attached to and governing the lever 
 direct. The pivots of this link are made free 
 from any appreciable lost motion, and will remain 
 so indefinitely; but if any such lost motion should 
 exist, it will affect the integrity of the parallel 
 movement only to an extent equal to it. The 
 parallel movement will be affected only by the 
 play in the pivots of the link, and not in any de- 
 gree or manner by the play of any other parts. 
 
CONSTRUCTION OF INDICATORS. 127 
 
 The force required to guide the lever in its 
 parallel movement is received on the pivots of 
 the link alone, where the friction it causes is 
 practically inappreciable. 
 
 With the slot and roller device this guiding 
 force is received on several rapidly moving- sur- 
 faces, multiplied in amount by leverage. The 
 same is true to a considerable extent of the plan 
 of attaching the link to the connecting rod. 
 
 FIG. 10. . _ v . . 
 
 The Paper Cylinder Movement. It is so con- 
 structed that the tension of the coiled drum 
 spring within the paper cylinder can;be increased 
 or decreased, for different speeds of engines. 
 As little or as much of the spring can be taken up 
 or let out as desired, thereby providing for fine 
 adjustments. 
 
 For high speeds the instrument will give ac- 
 curate results for all practical purposes, without 
 
128 
 
 CONSTRUCTION OF INDICATORS. 
 
 any special adjustments further than to give suf- 
 ficient tension to keep the cord taut at all points. 
 When exceptionally accurate work is desired, 
 the length of the diagram may be carefully 
 measured, and compared with the length of a 
 line traced on the paper when the engine is work- 
 ing slowly. If the diagram is found to differ in 
 
 length from this line, 
 vary the tension of 
 the spring till they 
 agree. The paper 
 cylinder, or "drum," 
 is now made with 
 covered top. 
 
 The leading pul- 
 ley for paper cylin- 
 der, the latest im- 
 provement in the 
 American Thomp- 
 son improved indica- 
 tor, was patented 
 FlG - n - June 26, 1883, and 
 
 consists (see Fig. 10) of a wheel which leads 
 the cord through the hole, in contact with the 
 scored wheel, over which the cord can be run to 
 any possible angle, to connect with the motion 
 wherever it may be, or of whatever kind. 
 
 The pulley works in a sleeve which rotates in 
 the stand according to the adjustments required, 
 and which is held in its position, where adjusted 
 by the thumb screw, which acts as a binding 
 screw working in the groove on the sleeve. By 
 this it is held in any position that may be chosen, 
 and yet is free to revolve the moment the bind- 
 ing screw is loosened, without any possibility of 
 
CONSTRUCTION OF INDICATORS. 129 
 
 interfering- with the motion by means of scarring 
 the sleeve or disturbing- the particles of metal on 
 surface. It also gives all the desired freedom of 
 motion and facility of adjustment. 
 
 By means of the set screw, the stand which 
 carries the wheel can be adjusted to run the cord 
 to any possible angle within a rang-e of 360. 
 
 In the double-pulley arrang-ement, as used in 
 other indicators, the range of adjustment is 
 limited, and in some cases the cord cannot be 
 made to run in a number of certain directions, 
 except in a grating 1 , roug-h and uneven manner. 
 
 In this improved swivel pulley the use of 
 carrying pulleys is done away with, and from the 
 fact that, no matter what the angle of deflection 
 may be, or what direction it may be necessary to 
 take the cord, it will work smoothly; for the 
 pulley face and the face of the groove on the 
 paper cylinder are always in the proper position, 
 one with the other, to take the cord to the mo- 
 tion, wherever that may be arranged. 
 
 In high speed, short stroke electric light en- 
 gines great range of adjustment is very impor- 
 tant; for considerable trouble is experienced 
 sometimes upon engines running 350 and 360 
 revolutions per minute, in arranging the cords so 
 as to use independent arcs, and in making such 
 connections with reference to right lines, that no 
 distortion of diagrams should be given. 
 
 It is provided with a "stop motion " (see Fig. 
 10), which is so arranged that the horn handle 
 screw can be screwed up against the post or stop 
 placed midway between paper cylinder and steam 
 cylinder so as to regulate the pressure of pencil 
 lead upon the paper. 
 
130 CONSTRUCTION OF INDICATORS. 
 
 The best and finest quality of steel wire is 
 used in making" our spring's; and they are all 
 wound on a mandrel and tempered in the most 
 careful manner by the oldest and most experi- 
 enced workmen in the business. 
 
 All spring's are wound on mandrels from 
 four to four and one-half threads to the inch, and 
 thereby give more wire to each spring-, and a 
 consequent less strain, than if wound, as in 
 spring's of other indicators, on mandrels two to 
 three threads to the inch. 
 
 Whatever grinding- is done to lig-hten a spring- 
 amounts to very little; in fact, at the most it is 
 
 FIG. 12. 
 
 never ground to cause more than one to three 
 pounds difference in 100 pounds; and, when the 
 sensitiveness of the spring is considered, very 
 little grinding will produce this result. 
 
 All springs made are scaled, providing for 
 vacuum; and the capacity of any spring can be as- 
 certained by the following general rule: Multiply 
 scale of spring by 2/^, and subtract 15, and the 
 result will be the limit of pounds steam pressure 
 to which spring should be subjected. Example: 
 40-pound spring X 2% = 100 15 == 85 pounds 
 pressure, capacity of a 40-pound spring. 
 
 To adapt the American Thompson improved 
 indicator to all pressures, springs are made to 
 any desired scale. The following are the most 
 generally used : 8, 10, 12, 16, 20, 24, 30, 32, 40, 48, 
 
CONSTRUCTION OF INDICATORS. 131 
 
 50, 56, 60, 64, 72, 80, 100. For pressures from 65 to 
 85 pounds, a 40-pound spring- is best adapted; 
 for, as 40 pounds pressure on a 40-pound spring- 
 will raise pencil one inch, 80 pounds pressure on 
 the same spring- will raise pencil about two 
 inches, which is the usual height of a diagram. 
 
 All the spring's are scaled providing- for 
 vacuum, but close experiments have shown 
 that, from the fact that spring's compress and 
 elong-ate in unlike proportions, the regular press- 
 ure springs vary about one pound in fifteen, or 
 about 6^i per cent. A special vacuum spring is 
 made with regular thread, scaled for vacuum only. 
 .. The detent motion, as applied to the American 
 Thompson indicator, consists of a pawl mounted 
 on a stud, combined with a spring 'and ratchet, 
 by the use of which the paper cylinder can be 
 stopped and a change of cards made without 
 unhooking or disconnecting the indicator cord. 
 
 By moving the pawl so as to catch in the 
 teeth of the ratchet on base of paper cylinder, 
 the latter is held stationary as the engine com- 
 pletes its stroke. The cord, being entirely free, 
 runs loosely with the motion of the engine, but 
 the paper cylinder being stationary, the cards 
 can be changed without the least disturbance of 
 adjustments. By throwing the pawl out of the 
 ratchet the paper cylinder is released, and im- 
 mediately resumes its stroke with the engine, 
 but care must be taken not to allow the paper 
 cylinder, by force of its spring, to return to the 
 stop with a thump; this can easily be done by 
 simply holding the cord slightly with the thumb 
 and finger until the beginning of the next stroke. 
 This device obviates the change of adjustments, 
 
132 
 
 CONSTRUCTION OF INDICATORS. 
 
 and is particularly valuable to amateurs and 
 others not familiar with the use of the indicator. 
 It is also valuable to users of the indicator on 
 very quick running- electric lig-ht engines, and in 
 all cases where the circumstances are such that 
 the disconnection of the connecting- cord must 
 cause the operator considerable trouble and the 
 loss of valuable time. 
 
 All American Thompson improved indicators 
 
 are provided with a 
 piston .798-inch di- 
 ameter = %-mch 
 area, which, with the 
 100-pound spring 1 , 
 provides for indicat- 
 ing pressure up to 
 250 pounds. 
 
 When pressure 
 above that is to be 
 indicated, an extra 
 pistonis furnishedof 
 .564-inch diameter^ 
 ^-inch area, which, 
 when substituted for 
 the >^-inch area pis- 
 ton, doubles the capacity of each spring-, thereby 
 adapting- the indicator for indicating- pressures 
 up to 500 pounds. 
 
 From the above it will be seen that when an 
 indicator is furnished with the regular ^2 -inch 
 area piston, and an extra %'-inch area piston in 
 addition, the instrument can be used to indicate 
 all pressures from to 500 pounds. 
 
 This indicator is constructed of steel for 
 ammonia compressor work. 
 
 FIG. 13. 
 
CONSTRUCTION OF INDICATORS. 133 
 
 CHAPTER VI. 
 
 THE TABOR INDICATOR. 
 
 The special peculiarity of the Tabor indicator 
 lies in the means employed to communicate a 
 straig-ht line movement to the pencil. This and 
 other features of the instrument are shown in 
 the appended cuts, and these are so clear that 
 little explanation is needed. A stationary plate 
 containing* a curved slot is firmly secured in an 
 upright position to the cover of the steam cylin- 
 der. This slot serves as a guide and controls 
 the motion of the pencil bar. The side of the 
 pencil bar carries a roller which turns on a pin, 
 and this fitted so as to roll freely from end to end 
 of the slot with little lost motion. The cur ve of the 
 the slot is so adjusted and the pin attached to 
 such a point, that the end of the pencil bar, which 
 carries the pencil, moves up and down in a 
 straight line, when the roller is removed from 
 one end of the slot to the other. The curve of 
 the slot just compensates the tendency of the 
 pencil point to move in a circular arc, and a 
 straight-line motion results. 
 
 The pencil mechanism is carried by the cover 
 of the outside cylinder. The cover proper is sta- 
 tionary, but a nicely fitted swivel plate, which ex- 
 tends over nearly the whole of the cover, is provid- 
 ed, and to this plate the direct attachment of the 
 pencilmechanismismade. By means of the swivel 
 plate, the pencil mechanism may be turned so as 
 to bring* the pencil into contact with the paper 
 drum, as is done in the act of taking a diagram. 
 
134 
 
 CONSTRUCTION OF INDICATORS. 
 
 The pencil mechanism is attached to the 
 swivel by means of the vertical plate containing 
 the slot, which has been referred to, and a small 
 standard placed on the opposite side of the swivel 
 for connecting- the back link. The slotted plate 
 is backed by another plate of similar size, which 
 serves to receive the pressure brought to bear 
 on the pencil bar when taking- diagrams, and to 
 keep the pencil bar in place. The pencil mechan- 
 ism consists of three pieces: The pencil bar, the 
 
 FIG. 14. 
 
 back link and the piston rod link. The two links 
 are parallel with each other in every position they 
 may assume. The lower pivots of these links 
 and the pencil point are always in the same 
 straig-ht line. If an imaginary link be supposed 
 to connect the two in such a manner as to be par- 
 allel with the pencil bar, the combination would 
 form an exact pantograph. The slot and roller 
 serve the purpose of this imaginary link. 
 
 The connection between the piston and the 
 
OF 
 
 CONSTRUCTION OF INDICATORS. 
 
 135 
 
 pencil mechanism is made by means of a steel 
 piston rod. At the upper end, where it passes 
 through the cover, it is hollow and has an outside 
 diameter measuring- three-sixteenths of an inch. 
 At the lower end it is solid and its diameter is 
 reduced. It connects with the piston througti a 
 ball and socket joint. The socket forms an in- 
 dependent piece, which fits into a square hole in 
 the center of the pis- 
 ton, and is fastened 
 by means of a central 
 stem provided with a 
 screw, which passes 
 through the hole and 
 receives a nut ap- 
 plied from the under 
 side. The nut has 
 a flat sided head, so 
 as to be readily oper- 
 ated by the fingers. 
 A number of shallow 
 grooves are cut upon 
 the outside of the piston, to serve as a so called 
 water packing 1 . 
 
 Purchasers of indicators have many import- 
 ant points to consider carefully before buying- an 
 instrument of such precision as an indicator 
 should be, to be reliable. One of the most im- 
 portant features of an indicator is the parallel 
 motion. It is one that has engrossed the atten- 
 tion of leading- engineers and inventors for the 
 past quarter of a century : that the correctness 
 of the parallel motion of the Tabor indicator is 
 such that at all times and at every point on a 
 diagram within the reacH of the pencil point, the 
 
 FIG. 15. 
 
136 CONSTRUCTION OF INDICATORS. 
 
 extreme end of the pencil bar will record a ver- 
 tical travel or movement of just five times that 
 of the indicator piston. 
 
 The spring's used in the Tabor indicator are 
 of the duplex type, being 1 made of two spiral 
 coils of wire with fitting's, as shown in the cut. 
 The springs are so mounted that the points of 
 connection of the two coils lie on opposite sides 
 of the fitting. This arrangement equalizes the 
 side strain on the spring, and keeps the piston 
 central in the cylinder, avoiding the excessive 
 friction caused by a single coil spring forcing 
 the piston against the side of the cylinder. The 
 thread by which the spring is attached is cut on 
 the inside of the fitting, and suitable threaded 
 projections on the under side of the cover and 
 on the upper side of the piston, respectively, are 
 provided for its attachment. 
 
 The springs are adjusted under steam press- 
 ure, and are, consequently, correct only when 
 used for steam engines. If required for water or 
 other purposes, either special springs should be 
 obtained that are adjusted with reference to the 
 required use, or the springs should be tested at 
 the time, and the actual scale of the spring deter- 
 mined. It should be borne in mind that a spring 
 becomes impaired by continued use, and its scale 
 changes. For important work, therefore, the 
 accuracy of the spring should always be tested 
 by comparison on the spot with a reliable steam 
 gauge, employing, as nearly as possible, the con- 
 ditions under which the instrument was used. 
 For steam work, they may be tested by attach- 
 ing to the main steam pipe, for this purpose, a 
 half-inch pipe fitted with a globe valve, a tee for 
 
CONSTRUCTION OF INDICATORS. 
 
 137 
 
 the attachment of the indicator, another tee for 
 the steam gauge, and finally a small drip valve. 
 By keeping- the drip valve slightly open and regu- 
 lating the globe valve, any desired pressures in 
 the apparatus can be secured. 
 
 The maximum safe steam pressures above 
 atmosphere, to which the various springs made 
 for the indicator can be subjected, are given in 
 the following table: 
 
 Scale of Spring. 
 
 Maximum Safe Pressure 
 to Which a Spring- can 
 be Subjected. 
 
 8 
 
 10 
 
 10 
 
 15 
 
 12 
 
 20 
 
 16 
 
 28 
 
 20 
 
 40 
 
 24 
 
 48 
 
 30 
 
 70 
 
 32 
 
 75 
 
 40 
 
 95 
 
 48 
 
 112 
 
 50 
 
 120 
 
 60 
 
 140 
 
 64 
 
 152 
 
 80 
 
 180 
 
 100 
 
 200 
 
 120 
 
 240 
 
 150 
 
 290 
 
 FIG. 16. 
 
 The paper drum turns on a vertical steel 
 shaft, secured at the lower end to the frame of 
 the indicator. The drum is supported at the 
 bottom by a carriage, which has a long vertical 
 bearing on the shaft. It is guided at the top by 
 the same shaft, which is prolonged for this pur- 
 pose, the drum being closed in at the top and 
 provided with a central bearing. The drum is 
 held in place by a close fit, in the usual manner, 
 and is easily removed by the hand when desired. 
 Stops are provided on the inside of the drum at 
 the bottom, with openings in the outside of the 
 
 (10) 
 
138 CONSTRUCTION OF INDICATORS. 
 
 carriage to correspond, so as to prevent the 
 drum from slipping-. These are so placed that 
 the position of the drum may be changed so as 
 to take diagrams in the reverse position of the 
 pencil mechanism, when so desired. The drum 
 is made of thin brass tubing, so as to be ex- 
 tremely light. Suitable strength is obtained by 
 leaving a ring of thicker metal at the bottom and 
 by employing the closed top. Steel clips are at- 
 tached to the drum for holding the paper. 
 
 The drum carriage projects below the lower 
 end of the drum, where it is provided with a 
 groove for the reception of the driving cord. 
 This groove has sufficient width for two com- 
 plete turns of the cord. The drum spring, by 
 which the backward movement of the drum is 
 accomplished, consists of a flat spiral spring of 
 the watch spring type, placed in a cavity under 
 the drum carriage encircling the bearing. It is 
 attached at one end to the frame below, and at 
 the other end to the drum carriage. In its normal 
 position the drum carriage is kept against a stop 
 by means of the pull of the spring. The lower 
 hub of the drum carriage rests directly on the 
 spring case, while the opposite hub is in contact 
 with a knurled thumb nut, screwed and pinned 
 to the drum stud, in a position to just give a 
 slight amount of end motion to the drum car- 
 riage. This thumb nut also serves as a con- 
 venient means of regulating the tension of the 
 drum spring, as by loosening the nut that screws 
 the spring case to the arm of the instrument, said 
 thumb nut can be turned in either direction until 
 the desired tension is obtained, and then again 
 tightening the nut. 
 
CONSTRUCTION OF INDICATORS. 139 
 
 A simple form of carrier pulley serves to 
 operate the driving- cord from any direction. A 
 single pulley is mounted within a circular per- 
 pendicular plate, the center of which coincides 
 with the center of the driving- cord. This center 
 also coincides with the circumference of the 
 pulley. The plate can be turned about its center 
 so as to swing- the pulley into any desired ang-ular 
 position, and thereby lead the cord off in any de- 
 sired direction. The plate is held by a circular 
 frame, which serves also as a clamp, and the 
 pulley is fixed in position by the use of the same 
 nut which secures the frame to the pulley arm. 
 
 Some of the prominent features in the design 
 and construction of the Tabor indicator, which 
 are noticeable to one handling the instrument, 
 may be mentioned: 
 
 The instrument is attached by means of a 
 coupling having but one thread. It is simple, 
 like a common pipe coupling, and is operated by 
 simply turning it in the proper direction, without 
 exercising that care which the use of couplings 
 having double threads requires. 
 
 The indicator cock has a stop which limits its 
 range in either direction to full open or closed, 
 and also has holes provided for the release of all 
 steam that may remain between the indicator 
 piston and cock after operating. 
 
 The pressure of the pencil on the paper drum 
 is regulated by means of a screw, which passes 
 through a projection on the slot plate, and strikes 
 against a small stop provided for the purpose, 
 which stands on the frame. This screw is 
 operated by a handle, which is of sufficient size 
 to be readily worked by the fingers, and which 
 
140 CONSTRUCTION OF INDICATORS. 
 
 also serves as a handle for turning* the pencil 
 mechanism back and forth, as is done in the act of 
 taking- diagrams. The handle may be intro- 
 duced and worked from either side, so as to use 
 the pencil mechanism on either side of the paper 
 drum. 
 
 The end of the pencil bar is shaped in the 
 form of a thin tube for the reception of the pencil 
 lead or metallic marking- point. The tube is split 
 apart on the side and yields to the slig-ht press- 
 ure required to introduce the pencil, which can 
 be introduced from either side, so as to mark on 
 either side of the paper drum desired. 
 
 The outside of the instrument in all its parts, 
 excepting- the pencil bar and links composing the 
 pencil mechanism, is nickel plated. The pencil 
 mechanism is made of steel, hardened and drawn 
 to a spring- temper, with blue finish. 
 
 Some of the dimensions of the parts in the 
 instrument of standard size are as follows: 
 
 Diameter of piston 0.7978 inches. 
 
 Diameter of paper drum 2.063 
 
 Stroke of paper drum 5.5 
 
 Height of paper drum 4. 
 
 Number of times pencil mechanism 
 
 multiplies piston motion 5. 
 
 Rang-e of motion of pencil point 3.25 
 
 A result of the care in designing- and con- 
 structing- these instruments is a reduction of 
 friction to the least possible amount. 
 
CONSTRUCTION OF INDICATORS. 141 
 
 CHAPTER VII. 
 
 THE IMPROVED VICTOR REDUCING WHEEL. 
 
 Recent improvements in the Victor reduc- 
 ing wheel make it near absolute perfection. 
 Every part is made of the material best suited 
 to the work, and each joint is so admirably fitted 
 that its lightness, accuracy and durability are 
 only equaled by the convenience and facility 
 with which it may be applied to any indicator, 
 stroke or speed. It has no gears, therefore no 
 grating- action. The cord wheel revolves on a 
 polished spindle. The wheel is stationary, and 
 the guide pulley is moved across its face a dis- 
 tance equal to the thickness of the cord for each 
 revolution, so that the cord will wind evenly, coil 
 to coil, no matter in what direction it is led. 
 
 The improved Victor aluminum reducing 
 wheel is made in two patterns, large and small. 
 The only difference in these patterns lies in the 
 diameter of the main cord wheel. The large 
 pattern is especially intended for strokes of four 
 feet and over, and will give perfect satisfaction 
 on strokes of eight feet. There are several in use 
 on high speed engines, but for this work the 
 smaller size is recommended, and guaranteed 
 to operate perfectly to any speed met with in 
 practice. 
 
 Both patterns are carried in stock, with special 
 arms D, Fig. 17, to fit all makes of indicators. 
 
 A feature of the Victor wheel is its extreme 
 simplicity, and the facility with which it may be 
 taken apart for cleaning and replacing springs. 
 
142 CONSTRUCTION OF INDICATORS. 
 
 By actual timing- the instrument has been taken 
 apart, a spring- replaced and assembled, ready 
 for use in three minutes. 
 
 One of the most important features in a re- 
 ducing- wheel is smooth running-. In fact, with- 
 out it an accurate diagram cannot be secured. 
 After many experiments the arrangement em- 
 ployed in the improved Victor, a heavy, braided 
 linen cord, which connects the small pulley E to 
 the spring- case F, Fig-. 17, was adopted. 
 
 FIG. 17. 
 
 This method transmits the power of the 
 spring- without friction, and as the cord is always 
 under a uniform tension, all stretch is soon elim- 
 inated. When worn out it may be replaced in a 
 moment and without cost. 
 
 The spring case, F^ is made of aluminum, 
 and is deeply grooved, so that the intermediate 
 cord can never ride, and is perfectly guided at 
 all times. 
 
 The freedom from friction, which is one of 
 the most pleasing and noticeable features of the 
 Victor wheel, insures its operation with much 
 
CONSTRUCTION OF INDICATORS. 143 
 
 less spring- tension than others, which means 
 longer life of the spring-. 
 
 The cord wheel revolves on a polished steel 
 spindle, so that a nice fit may be made and main- 
 tained, even after years of ordinary use. 
 
 The improved Victor wheel is provided with 
 bushings for all strokes. These bushings, B, 
 are quickly changed. 
 
 It is manufactured by James L. Robertson & 
 Son, 204 Fulton street, New York city. 
 
144 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER VIII. 
 
 THE IDEAL REDUCING WHEEL. 
 
 The object of the reducing" wheel is to reduce 
 accurately the motion of an engine cross-head to 
 that required for a paper drum of an indicator, 
 and to give the required length of diagram 
 regardless of the engine stroke. If either the 
 indicator or reducing- motion is not correct, the 
 cards are useless and deceptive, hence the first 
 step toward obtaining- the true state of affairs in 
 a steam cylinder is an indicator that will show 
 both the true pressure, or vacuum, and a cor- 
 rect reducing- motion by which diagrams can be 
 taken, so that an intellig-ent engineer can inter-, 
 pret them, adjust the valves and figure the power 
 developed. 
 
 The Ideal reducing wheel is made of alumi- 
 num, brass and steel, combining strength and 
 lightness, two essential features, together with 
 first-class workmanship. 
 
 The wheel or drum, from which the cord 
 passes to the cross-head is only two and three- 
 quarters inches in diameter, and is made of 
 aluminum. The coil spring for the take-up is in 
 a case two and one-quarter inches in diameter, 
 and connected by a 3 to 1 gear with the cord 
 wheel spindle, so that while the light alumi- 
 num cord wheel makes three revolutions, the 
 spring makes but one. The spring can be ad- 
 justed to any desired tension, to keep the cord 
 taut on return stroke. The cord wheel revolves 
 on a steel screw, the thread of which is the same 
 
CONSTRUCTION OF INDICATORS. 145 
 
 pitch as the cord, so that when the cord is drawn 
 out the wheel travels as -it revolves. By this 
 means the cord is wound smoothly on the drum 
 and passes straight through the guide pulley. 
 
 To use the reducing wheel on the indicator, 
 remove the carrier pulley from the indicator, and 
 put the wheel on in place of it. Pass the drum 
 cord around the small disk through the hole and 
 under the holder, being careful to see that the 
 cord is wound around the bushing or disk from 
 the left, as shown in Fig. 18. Before attaching hook 
 see that cord on the wheel and indicator is taut 
 at shortest part of the stroke, and that it will 
 
 FIG. 18. 
 
 pull out a little further than the longest part of 
 vStroke. The reducing wheel can be used in any 
 place where it is most convenient, bearing in mind 
 that the cord from it to the cross-head should run 
 in a straight line. In unhooking the cord, allow 
 it to return slowly until the stop reaches the 
 guide pulley. 
 
 Bushings of various sizes are furnished so 
 that cards can be taken from any length of stroke 
 up to seventy-two inches. 
 
 Theldealreducingwheel is manufactured only 
 by John S. Bushnell, successor to Thompson & 
 Bushnell, 120-122 Liberty street, New York city. 
 
146 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER IX. 
 
 SARGENT'S ELECTRICAL ATTACHMENT FOR STEAM 
 ENGINE INDICATORS. 
 
 In making- elaborate tests of power plants, it 
 has heretofore been necessary to employ as 
 many assistants as there were indicators used, 
 but the difficulty of securing- simultaneous action 
 on their part is so great that satisfactory work 
 is rarely obtainable, and more certain means to 
 that end are now considered necessary. 
 
 Mr. Frederick Sargent, M.E., invented and 
 patented an electrical device applicable to an in- 
 dicator, by means of which any number of in- 
 struments can be operated and diagrams taken 
 at the same instant of time, simply by closing an 
 electric circuit. 
 
 Fig-. 19 shows a Crosby indicator fitted with 
 a Sarg-ent electrical attachment. 
 
 For the purpose of illustrating- the manner of 
 operating- the attachment, assume that it is desir- 
 able to procure simultaneous diagrams from a 
 compound eng-ine, taking- cards from the ends of 
 each cylinder. Attach the indicators to the en- 
 gine and arrange the drum motion in the usual 
 manner. On each indicator secure the electrical 
 attachment to its plate. Make the connections 
 with the battery, having all of the several magnets 
 and the circuit closer in series. Place the paper 
 upon the drum and bring the pencil arm into 
 such a position as will allow the latch to drop 
 into the screw eye. 
 
 Press the armature firmly against the magnet 
 
CONSTRUCTION OF INDICATORS. 
 
 147 
 
 and adjust the marking- point to the paper in the 
 usual manner. The sleeve handle must be un- 
 screwed enough to allow the full operation of the 
 armature. The circuit should be closed and the 
 armature tension spring's adjusted, so that the 
 connected attachment will work simultaneously. 
 Everything- should now be in readiness to take 
 diagrams. Connect the drum motions, open the 
 indicator cocks, and as soon as desirable close 
 
 FIG. 19. 
 
 the circuit, and instantly all of the pencils will be 
 broug-ht ag-ainst the papers and will remain there 
 as long- as the circuit is kept closed. 
 
 In order to put on new papers, diseng-ag-e the 
 drum motions, lift the latch and swing- the pencil 
 arm out of the way. 
 
 The amount of battery power required will 
 vary with circumstances and will-rang-e from one 
 to two or more cells of a No. 2 Sampson battery, 
 or its equivalent. 
 
148 CONSTRUCTION OF INDICATORS. 
 
 The battery for operating- the attachment is 
 inclosed in a neat hardwood box with a suitable 
 handle for carrying 1 it, and is sealed so as to pre- 
 vent slopping-. It is very compact and portable, 
 being- at the same time extremely active, long- 
 lived and especially adapted to open circuit work. 
 
 The connections to the indicator attachments 
 can be made with the battery without opening 
 the box, the binding- posts being- on the outside. 
 This battery, with a quantity of suitable wire 
 for making- connections, is furnished with the 
 attachment. The Sarg-ent electrical attachment 
 is manufactured by the Crosby Steam Gag-e and 
 Valve Co., Boston, Mass. 
 
CONSTRUCTION OF INDICATORS. 149 
 
 CHAPTER X. 
 
 AMSLER'S POLAR PLANIMETER, WITH DIRECTIONS 
 FOR USING IT ON INDICATOR DIAGRAMS. 
 
 Fig-. 20 represents the No. 1 plani meter. It 
 is the simplest form of the instrument, having 
 but one wheel, and is designed to measure areas 
 in square inches and decimals of a square inch. 
 The figures on the roller wheel D represent 
 units, the graduations on the wheel represent 
 tenths, and the vernier gives the hundredths. 
 
 The use of Amsler's polar planimeter in the 
 measurement of indicator diagrams enables one 
 
 - FIG. 20. 
 
 to measure ten cards with it in the time which 
 would be required to measure one card by any 
 other method, and it insures the utmost accuracy 
 in the work. 
 
 The planimeter is a precise and delicate in- 
 strument, and should be handled and kept with 
 great care, in order that it may be depended 
 upon to give correct results. After using, it 
 should be wiped clean with a piece of soft chamois 
 skin. 
 
 The Amsler polar planimeter is manufact- 
 ured by the Crosby Steam Gage and Valve Co., 
 Boston, Mass. 
 
150 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER XL 
 
 THE LIPPINCOTT PLANIMETER. 
 
 The accompanying engraving-, Fig. 21, repre- 
 sents a new form of planimeter. 
 
 It will be noticed that the wheel has a knife 
 edge, and is free to move on its shaft, so that 
 there can be no slipping- on the surface upon 
 which it moves, giving- the same results when 
 used upon the roug-hest table as upon the finest 
 paper. 
 
 As the rotary movement of this wheel does 
 not register, it is apparent that the accuracy of 
 
 FIG. 21. 
 
 the instrument will not be affected by any re- 
 duction of the diameter of the wheel or injury 
 to the knife edge. This is one of the most im- 
 portant points to be considered in the selection 
 of a planimeter. It is evident, however, that 
 this claim is only made possible by taking the 
 reading from the hub and not from the edge of 
 the wheel. The possibility of a vitiated reading 
 
CONSTRUCTION OF INDICATORS, 151 
 
 on account of the knife edge coming* in contact 
 with separate scale, is also avoided thereby. 
 
 With the Lippincott planimeter the sliding- is 
 done entirely upon the shaft, and as this shaft is 
 made of glass it is practically frictionless. 
 
 The pivot screw is made hollow, and by 
 means of a small knob a sharp point may be pro- 
 truded for convenience in setting- to the card 
 leng-th, while a small spiral spring- normally holds 
 it in a protected position after the setting- opera- 
 tion has been completed. 
 
 It will thus be seen that any bending- in the 
 tracer point would be compensated for in every 
 setting-, and could therefore occasion no error. 
 This is a most important improvement, and 
 guarantees initial and continued accuracy. 
 
 Inside the glass shaft is placed the scale, 
 which is printed upon specially prepared paper, 
 so that the greatest contrast and legibility may 
 be insured. The ends of this shaft are then 
 hermetically sealed under a partial vacuum, so 
 that the scale can never become discolored or 
 affected by the atmosphere. 
 
 The plates employed in printing- these scales 
 are engine divided and mathematically correct. 
 
 Three of these scale tubes are provided with 
 the instrument, each containing- two. different 
 graduations, so that the mean effective pressure 
 may be read direct, without computation, for the 
 following- indicator springs: 6, 8, 10, 12, 16, 20, 
 24, 30, 32, 40, 50, 60, 80, 100, 120 and 150. For 
 instance, if it is required to ascertain the M. 
 E. P. of a card taken with an 80 spring-, insert 
 a tube containing a 40 scale, and mentally 
 double the reading 1 ; or if special accuracy is 
 
152 CONSTRUCTION OF INDICATOKS. 
 
 desired, trace the diagram twice, without stop- 
 ping, and the reading- will be correct for an 80- 
 pound spring-. 
 
 The correct reading- for a 20 spring- may be 
 had from a 40 scale also, and in like manner 
 other scales may be used with different spring's, 
 which is more desirable than to encumber the 
 case with a number of useless scale tubes. 
 
 Any special graduation will be furnished to 
 order. 
 
 To use the instrument, select a tube contain- 
 ing a scale corresponding to spring used in tak- 
 ing the card, and insert same in the clamp, as in 
 Fig. 21, after which the clamp screw is to be 
 tightened sufficiently to prevent the tube from 
 being easily moved. 
 
 Loosen the set screw, and adjust the points 
 to the exact length of the card. The set screw 
 should then be firmly tightened, so that the 
 tracer bar cannot be moved in the frame block. 
 
 Having fastened the card upon the table with 
 thumb tacks, place the instrument with radial 
 bar at right angles to the tracer bar. After this 
 move the tracer point down to point 7\ The left 
 hand edge of the wheel hub may then be set at 
 zero, either by moving the radial point /? to the 
 right or left, or by moving the wheel on the shaft. 
 After the instrument is properly placed, the 
 tracer point should trace the line of the diagram 
 to the left, in the direction taken by the hands of 
 a watch, noting carefully that the wheel does not 
 strike at either end of the shaft in making the 
 circuit. 
 
 If a reading is desired in square inches, use a 
 40 scale and set the points four inches apart. 
 
CONSTRUCTION OF INDICATORS. 153 
 
 The points may also set five inches apart and a 
 50 scale used, or six inches and a 60 scale. 
 The latter is preferable in taking- the area of 
 large figures. 
 
 Use no oil on any part of the instrument, and 
 keep the glass tube perfectly clean with tissue 
 paper, or clean chamois skin. The wheel should 
 slide with perfect freedom from one end of the 
 tube to the other. 
 
 This instrument is packed in a fine morocco 
 velvet lined case, with nickel trimming's, and 
 every one is guaranteed perfectly accurate. It is 
 manufactured by James L. Robertson & Sons, 
 204 Fulton street, New York city. 
 
 (ii) 
 
154 CONSTRUCTION OF INDICATORS. 
 
 CHAPTER XII. 
 
 THE COFFIN AVERAGING INSTRUMENT FOR CALCU- 
 LATING INDICATOR DIAGRAMS. 
 
 When the mean effective pressure on a large 
 number of diagrams is desired, time and labor 
 may be saved by the employment of an averaging 
 instrument or planimeter, an instrument de- 
 signed to measure the areas of irregular figures. 
 It is operated by moving a tracer, with which it 
 is fitted, over the line of the diagram, and it 
 records the area upon a graduated wheel. 
 
 In using the Coffin averager, the grooved 
 metal plate, /, is first connected to the board upon 
 which the apparatus is mounted, in the position 
 shown in the cut, being held in place by a thumb- 
 screw applied from the back side. The indi- 
 cator card is then placed under the clamps Cand 
 K, which may be sprung away from the board a 
 sufficient amount to allow the card to be intro- 
 duced, and the card is moved toward the left into 
 such a position that the atmospheric line is near 
 to and parallel with the lower edge of the station- 
 ary clamp, C, while the extreme left hand end of 
 the diagram is even with the perpendicular edge 
 of the clamp. The movable clamp, K, which is 
 fastened at the bottom to a sliding plate, is then 
 moved toward the left, till the vertical beveled 
 edge just touches the extreme right hand end of 
 the diagram. The diagram shown in the cut 
 represents the proper location which should ex- 
 ist when these preliminary adjustments have 
 been completed. The slide at the bottom of 
 
CONSTRUCTION OF INDICATORS. 
 
 155 
 
 clamp A'fits closely, so- that the application of a 
 slig-ht pressure with the thumb or finger is re- 
 quired to displace it. 
 
 FIG. 22. 
 
 The beam of the instrument is next placed on 
 the board, with the pin at the lower end resting- 
 in the groove, /, and the weig-ht, Q, applied to the 
 top of the pin so as to keep it securely in place. 
 
156 CONSTRUCTION OF INDICATORS. 
 
 The tracer, O, is moved to the right hand end of 
 the diagram and set at the point D, on the line of 
 the diagram, where the clamp K and the diagram 
 touch each other. Here a slight indentation is 
 made in the paper by pressing the finger on the 
 top of the tracer, and this serves as a starting 
 point. The graduated wheel is next turned so 
 as to bring its zero mark to the zero mark on the 
 vernier. The instrument is now ready for 
 operation. The tracer, O, is carefully moved 
 over the line of the diagram, in the direction of 
 motion of the hands of a watch, and continued till 
 a complete circuit is made and the tracer finally 
 reaches the starting point, D. Keeping an eye 
 on the wheel, the tracer is now moved upward by 
 sliding it along the edge of the clamp K, until the 
 reading on the wheel returns to zero. Another 
 light indentation is made in the paper to mark the 
 new position which the tracer occupies. This 
 point is represented at A in the cut. The in- 
 strument is now moved away, the clamp pushed 
 back, and the distance between the two points, D 
 and A, is measured by employing a scale corre- 
 sponding to the number of the spring used in the 
 indicator. The distance thus found is the mean 
 effective pressure, expressed in pounds per 
 square inch of piston. 
 
 The Coffin planimeter determines the desired 
 result without computation, but it may be used 
 also for determining the area inclosed- by the 
 diagram. This area is given by the reading on 
 the graduated wheel, when the circuit of the 
 diagram has been made and the tracer reaches 
 the starting point, D. The wheel has fifteen 
 main divisions, each of which represents one 
 
CONSTRUCTION OF INDICATORS. 157 
 
 square inch of area. Each division has five sub- 
 divisions, each sub-division representing- one- 
 fifth, or two-tenths, of a square inch of area. 
 The vernier scale enables the sub-divisions to be 
 read in fiftieths, each of these fiftieths, therefore, 
 representing- two-one-hundredths of a square 
 inch. Having- obtained the area in this manner, 
 the mean effective pressure may be computed 
 by dividing- the number of the spring- represent- 
 ing- the pressure per inch in heig-ht by the leng-th 
 of the diagram (inches) and multiplying the 
 quotient by the area (square inches). In first 
 placing- the indicator card under the clamps, 
 care must be observed that the ends of the dia- 
 gram set a little away from the edg-e of the clamp, 
 so as to allow for one-half the diameter of the 
 tracer, and to bring- the center of the tracer over 
 the center of the line of the diagram. 
 
PART IV. 
 MISCELLANEOUS TABLES. 
 
160 
 
 MISCELLANEOUS TABLES. 
 
 PROPERTIES OF SATURATED AMMONIA. 
 
 CALCULATED FROM THE ORIGINAL FORMULA OF PROF. DE 
 VOLSON WOOD, BY GEORGE DAVIDSON, M.E. 
 
 Computed especially for and originally published in Ice and Refriger- 
 ation for December, 1894. 
 
 Tempera- 
 
 Pressure, 
 
 gd 
 
 41 
 
 oi 
 
 2s 
 
 S_o 
 
 5 - 
 
 
 ture. 
 
 Absolute. 
 
 3 
 
 SB 
 
 d 
 
 o^" 5 
 
 
 0"* 
 
 , 
 
 
 9 
 
 
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 > 
 
 >* 
 
 3|f 
 
 fj s 
 
 3jJ 
 
 S 
 
 || 
 
 C 
 
 en 
 
 Q 
 
 l 
 
 1* 
 
 
 
 OD a 
 
 >! 
 
 - 
 
 i* 
 
 !* 
 
 *s 
 
 2 o 
 
 U 
 
 f 
 
 I 
 
 f& 
 
 F 
 
 fS-S 
 
 |;, 
 
 3 &S 
 
 3 gj.2 
 
 o 0*0 
 
 pi 
 
 '55. So 
 
 4> 4> 
 
 HQ 
 
 40 
 
 420.66 
 
 1539.90 
 
 10.69 
 
 4.01 
 
 579.67 
 
 24.388 
 
 .02348 
 
 .0410 
 
 42.589 
 
 40 
 
 39 
 
 1 
 
 1584.43 
 
 11.00 
 
 3.70 
 
 579.07 
 
 23.735 
 
 .02351 
 
 .0421 
 
 42.535 
 
 39 
 
 38 
 
 2 
 
 16! JO. 03 
 
 11.32 
 
 3.38 
 
 578.42 
 
 23.102 
 
 .02354 
 
 .0433 
 
 42.483 
 
 38 
 
 87 
 
 3 
 
 1676.71 
 
 11.64 
 
 3.06 
 
 577.88 
 
 22.488 
 
 .02357 
 
 .0444 
 
 42.427 
 
 37 
 
 36 
 
 4 
 
 1724.51 
 
 11.98 
 
 2.72 
 
 577.27 
 
 21.895 
 
 .02359 
 
 .0457 
 
 42.391 
 
 36 
 
 -36 
 
 425.66 
 
 1773.43 
 
 12.31 
 
 2.39 
 
 576.68 
 
 21.321 
 
 .02362 
 
 .0469 
 
 42.337 
 
 35 
 
 34 
 
 6 
 
 18*3.50 
 
 12.66 
 
 -2,04 
 
 576.08 
 
 20.763 
 
 .02364 
 
 .0482 
 
 42.301 
 
 34 
 
 33 
 
 7 
 
 1874.73 
 
 13.02 
 
 -1.68 
 
 575.48 
 
 20.221 
 
 .02366 
 
 .0495 
 
 42.265 
 
 33 
 
 32 
 
 8 
 
 1927.17 
 
 13.38 
 
 -1.32 
 
 574.89 
 
 19.708 
 
 .02368 
 
 .0507 
 
 42.213 
 
 32 
 
 31 
 
 9 
 
 1980.78 
 
 13.75 
 
 0.95 
 
 574.39 
 
 19.204 
 
 .02371 
 
 .0521 
 
 42.176 
 
 31 
 
 30 
 
 430.66 
 
 2035.69 
 
 14.13 
 
 0.57 
 
 573.69 
 
 18.693 
 
 .02374 
 
 .0535 
 
 42.123 
 
 30 
 
 29 
 
 1 
 
 2091.83 
 
 14.53 
 
 0.17 
 
 573,08 
 
 18.225 
 
 .02378 
 
 .0519 
 
 42.052 
 
 29 
 
 28 
 
 2 
 
 2149.23 
 
 14.92 
 
 +0.22 
 
 572.48 
 
 17.759 
 
 .02381 
 
 .0563 
 
 42.000 
 
 28 
 
 27 
 
 3 
 
 2207.94 
 
 15.33 
 
 +0.63 
 
 571.89 
 
 17.307 
 
 .02384 
 
 .0577 
 
 41.946 
 
 27 
 
 26 
 
 4 
 
 2267.97 
 
 15.76 
 
 +1.05 
 
 571.28 
 
 16.869 
 
 .02387 
 
 .0593 
 
 41.893 
 
 26 
 
 25 
 
 435.66 
 
 2329.34 
 
 16.17 
 
 +1.47 
 
 570.68 
 
 16.446 
 
 .02389 
 
 .0608 
 
 41.858 
 
 -25 
 
 24 
 
 6 
 
 2392.09 
 
 16.61 
 
 1.91 
 
 570.08 
 
 16.034 
 
 .02392 
 
 .0624 
 
 41.806 
 
 24 
 
 23 
 
 7 
 
 2456.23 
 
 17.05 
 
 2.35 
 
 569.48 
 
 15.633 
 
 .02395 
 
 .0640 
 
 41.754 
 
 23 
 
 22 
 
 8 
 
 2520.46 
 
 17.60 
 
 2.8 
 
 568.88 
 
 15.252 
 
 .02398 
 
 .0656 
 
 41.701 
 
 22 
 
 21 
 
 9 
 
 2588.77 
 
 17.97 
 
 3.27 
 
 568.27 
 
 14.875 
 
 .02401 
 
 .0672 
 
 41.649 
 
 21 
 
 20 
 
 440.66 
 
 2657.23 
 
 18.45 
 
 +3.75 
 
 567.67 
 
 14.507 
 
 .02403 
 
 .0689 
 
 41.615 
 
 -20 
 
 19 
 
 1 
 
 2727.17 
 
 18.94 
 
 4.24 
 
 567.06 
 
 14.153 
 
 .02406 
 
 .0706 
 
 41.563 
 
 19 
 
 18 
 
 2 
 
 2798.62 
 
 19.43 
 
 4.73 
 
 566.43 
 
 13.807 
 
 .02409 
 
 .0725 
 
 41.511 
 
 18 
 
 17 
 
 3 
 
 2871:61 
 
 19.94 
 
 5.24 
 
 565.85 
 
 13.475 
 
 .02411 
 
 .0742 
 
 41.480 
 
 17 
 
 16 
 
 4 
 
 2946.17 
 
 20.46 
 
 5.76 
 
 565.25 
 
 13.150 
 
 .02414 
 
 .0760 
 
 41.425 
 
 16 
 
 15 
 
 445.66 
 
 3022.31 
 
 20.99 
 
 +6.29 
 
 564.64 
 
 12.834 
 
 .02417 
 
 .0779 
 
 41.374 
 
 15 
 
 14 
 
 6 
 
 3100.07 
 
 21.53 
 
 6.83 
 
 564.04 
 
 12.527 
 
 .02420 
 
 .0798 
 
 41.322 
 
 14 
 
 13 
 
 7 
 
 3179.45 
 
 22.08 
 
 7.38 
 
 563.43 
 
 12.230 
 
 .02423 
 
 .0818 
 
 41.271 
 
 13 
 
 12 
 
 8 
 
 3260.52 
 
 22.64 
 
 7.94 
 
 568. -82 
 
 11.939 
 
 .02425 
 
 .0838 
 
 41.237 
 
 12 
 
 11 
 
 9 
 
 3343.29 
 
 23.22 
 
 8.52 
 
 562.21 
 
 11.659 
 
 .02428 
 
 
 41 186 
 
 11 
 
 10 
 
 450.66 
 
 3427.75 
 
 23.80 
 
 +9.10 
 
 561.61 
 
 11.385 
 
 .02431 
 
 .0878 
 
 41.135 
 
 10 
 
 9 
 
 1 
 
 3513.97 
 
 24.40 
 
 9.70 
 
 560.99 
 
 11.117 
 
 .02434 
 
 .0899 
 
 41.084 
 
 9 
 
 8 
 
 2 
 
 3601.97 
 
 25.01 
 
 10.31 
 
 560.39 
 
 10.860 
 
 .02437 
 
 .0921 
 
 41.034 
 
 8 
 
 7 
 
 3 
 
 3691.75 
 
 25.64 
 
 10,94 
 
 559.78 
 
 10.604 
 
 .02439 
 
 .0943 
 
 41.000 
 
 7 
 
 6 
 
 4 
 
 3783.37 
 
 26.27 
 
 11.57 
 
 559.17 
 
 10.362 
 
 .02442 
 
 .0965 
 
 40.950 
 
 6 
 
 5 
 
 455.66 
 
 3876. &> 
 
 26.92 
 
 12.22 
 
 558.56 
 
 10.125 
 
 .02445 
 
 .0988 
 
 40.900 
 
 5 
 
 4 
 
 6 
 
 3972.62 
 
 27.59 
 
 +12.89 
 
 557.94 
 
 9.894 
 
 .02448 
 
 .1011 
 
 40.845 
 
 4 
 
 3 
 
 7 
 
 4069.48 
 
 28.26 
 
 13.56 
 
 557.33 
 
 9.669 
 
 .02451 
 
 .10H4 
 
 40.799 
 
 3 
 
 2 
 
 8 
 
 4168.70 
 
 28.95 
 
 14.25 
 
 556.73 
 
 9.449 
 
 02454 
 
 .1058 
 
 40.749 
 
 2 
 
 1 
 
 
 4269.90 
 
 29.65 
 
 14.95 
 
 556.11 
 
 9.234 
 
 .02457 
 
 .1083 
 
 40.700 
 
 1 
 
 
 
 460.66 
 
 4373.10 
 
 30.37 
 
 +15.67 
 
 555.50 
 
 9.028 
 
 .02461 
 
 .1107 
 
 40.650 
 
 
 
 +1 
 
 1 
 
 4478.32 
 
 31 10 
 
 16.40 
 
 554.88 
 
 8.825 
 
 .02463 
 
 .1133 
 
 40.601 
 
 + 1 
 
 2 
 
 
 4485.60 
 
 31.84 
 
 17.14 
 
 554.27 
 
 8.630 
 
 .0246H 
 
 .1159 
 
 40.551 
 
 2 
 
 3 
 
 '3 
 
 4694.96 
 
 32.60 
 
 17.90 
 
 553.65 
 
 8.436 
 
 .02469 
 
 .1186 
 
 40.502 
 
 jj 
 
 4 
 
 4 
 
 4806.46 
 
 33.38 
 
 18.68 
 
 553.04 
 
 8.250 
 
 .02472 
 
 .1212 
 
 40.453 
 
 4 
 
 * For values at temperatures higher than 100 F. see Wood's 
 table on page 163. 
 
MISCI<:LLAN?:OUS TABLES. 
 
 161 
 
 PROPERTIES OF SATURATED AMMONIA. 
 
 CALCULATED FROM THE ORIGINAL FORMULA OF PROF. DE 
 
 VOLSON WOOD, BY GEORGE DAVIDSON, M.E. 
 Computed especially for and originally published in Ice and Refriger- 
 ation for December, 1894. 
 
 Tempera- 
 ture. 
 
 Pressure, 
 Absolute. 
 
 Gauge Pressure, 
 Pouud per Sq. 
 Inch. 
 
 111 
 
 id* 
 
 iji 
 
 j15 
 
 !&* 
 
 W 
 
 p 
 
 n 
 
 m 
 
 Temperature. 
 Degrees F. |l 
 
 EL. 
 
 Absolute. 
 T, 
 
 f* 
 
 m 
 
 | 
 
 +5 
 
 465.66 
 
 4920.11 
 
 34.16 
 
 +19.46 
 
 552.43 
 
 8.070 
 
 02475 
 
 1240 
 
 40.404 
 
 +5 
 
 6 
 
 6 
 
 5035.95 
 
 4.97 
 
 20.27 
 
 651.81 
 
 7.892 
 
 02478 
 
 1267 
 
 40.355 
 
 6 
 
 7 
 
 7 
 
 5153.99 
 
 5.79 
 
 21.09 
 
 551.19 
 
 7.717 
 
 02480 
 
 1296 
 
 40.322 
 
 7 
 
 8 
 
 8 
 
 5274.28 
 
 6.63 
 
 21.93 
 
 550.58 
 
 7.553 
 
 02483 
 
 1324 
 
 40.274 
 
 8 
 
 9 
 
 9 
 
 5396.83 
 
 7.48 
 
 22.78 
 
 549.96 
 
 7.388 
 
 02486 
 
 1353 
 
 40.226 
 
 9 
 
 flO 
 
 70.66 
 
 5521.71 
 
 38.34 
 
 +23.64 
 
 549.35 
 
 7.229 
 
 02490 
 
 1383 
 
 40.160 
 
 +10 
 
 11 
 
 1 
 
 6649.48 
 
 9.23 
 
 24.53 
 
 548.73 
 
 7.075 
 
 02493 
 
 1413 
 
 40412 
 
 11 
 
 12 
 
 2 
 
 5778.50 
 
 4043 
 
 25.43 
 
 548.11 
 
 6.924 
 
 02496 
 
 1444 
 
 40.064 
 
 12 
 
 13 
 
 3 
 
 5910.52 
 
 1.04 
 
 26.34 
 
 547.49 
 
 6.786 
 
 02499 
 
 1474 
 
 40.016 
 
 13 
 
 14 
 
 4 
 
 6044.96 
 
 1.98 
 
 27.28 
 
 546.88 
 
 6.632 
 
 02502 
 
 1507 
 
 39.968 
 
 14 
 
 +15 
 
 475.66 
 
 6182.00 
 
 42.94 
 
 +28.24 
 
 546.26 
 
 6.491 
 
 02505 
 
 1541 
 
 39.920 
 
 +16 
 
 16 
 
 6 
 
 6321.24 
 
 3.90 
 
 29.20 
 
 545.63 
 
 6.355 
 
 02508 
 
 1573 
 
 39.872 
 
 16 
 
 17 
 
 7 
 
 6463.24 
 
 44.88 
 
 3048 
 
 545.01 
 
 6.222 
 
 02511 
 
 1607 
 
 39.872 
 
 17 
 
 18 
 
 8 
 
 6607.77 
 
 45.89 
 
 3149 
 
 544.39 
 
 6.093 
 
 02514 
 
 1641 
 
 <J9.777 
 
 18 
 
 19 
 
 9 
 
 6754.90 
 
 46.91 
 
 32.21 
 
 543.74 
 
 5.966 
 
 02517 
 
 4676 
 
 39.729 
 
 19 
 
 +20 
 
 480.66 
 
 6904.68 
 
 47.95 
 
 +33.25 
 
 543.15 
 
 5.843 
 
 02520 
 
 .1711 
 
 39.682 
 
 +20 
 
 21 
 
 1 
 
 7057.15 
 
 49.01 
 
 34.31 
 
 642.53 
 
 5.722 
 
 02523 
 
 1748 
 
 39.635 
 
 21 
 
 22 
 
 2 
 
 7211.33 
 
 50.09 
 
 35.39 
 
 541.90 
 
 5-. 605 
 
 02527 
 
 .1784 
 
 39.572 
 
 22 
 
 23 
 
 3 
 
 7370.27 
 
 51.18 
 
 36.48 
 
 641 38 
 
 5.488 
 
 .0^539 
 
 4822 
 
 39.541 
 
 23 
 
 
 4 
 
 7530.96 
 
 52.30 
 
 37.60 
 
 540.66 
 
 5.378 
 
 .02533 
 
 .1860 
 
 39.479 
 
 24 
 
 +26 
 
 485.66 
 
 7694.52 
 
 5343 
 
 +38.73 
 
 540.03 
 
 5.270 
 
 .02536 
 
 4897 
 
 39.432 
 
 +25 
 
 26 
 
 6 
 
 7860.89 
 
 54.59 
 
 39.89 
 
 539.41 
 
 5.163 
 
 .02539 
 
 493; 
 
 39.386 
 
 26 , 
 
 27 
 
 7- 
 
 8030-16 
 
 55.76 
 
 41.06 
 
 538.78 
 
 6.068 
 
 .02542 
 
 4977 
 
 39.339 
 
 27 J 
 
 88 
 
 8 
 
 8202.38 
 
 66.96 
 
 42.26 
 
 538.16 
 
 4.960 
 
 .02545 
 
 .2016 
 
 39.292 
 
 28 
 
 29 
 
 9 
 
 8377-56 
 
 5847 
 
 43.47 
 
 537.63 
 
 4.858 
 
 .02548 
 
 .2059 
 
 39.246 
 
 29 
 
 +30 
 
 490.66 
 
 8555.74 
 
 59.42 
 
 +44.72 
 
 536.91 
 
 4.763 
 
 .02551 
 
 .2099 
 
 39.200 
 
 +30 
 
 31 
 
 1 
 
 8736.96 
 
 60.67 
 
 45.97 
 
 536.28 
 
 4.668 
 
 .02554 
 
 .2142 
 
 39415 
 
 31 
 
 32 
 
 2 
 
 8921.26 
 
 61.95 
 
 47.25 
 
 535.66 
 
 4.577 
 
 .02557 
 
 .2185 
 
 39408 
 
 32 
 
 33 
 
 3 
 
 9108.71 
 
 63.25 
 
 48.55 
 
 535.03 
 
 4.486 
 
 .02561 
 
 .2229 
 
 39.047 
 
 33 
 
 34 
 
 4 
 
 9299.32 
 
 64.58 
 
 49.88 
 
 534.40 
 
 4.400 
 
 .02664 
 
 .2273 
 
 39.001 
 
 34 
 
 +35 
 
 495.66 
 
 9493.07 
 
 65.92 
 
 +51.22 
 
 533.78 
 
 4.314 
 
 -.02568 
 
 .2318 
 
 38.940 
 
 +35 
 
 36 
 
 6 
 
 9690.04 
 
 67.29 
 
 52.59 
 
 633.13 
 
 4.234 
 
 .02571 
 
 .2362 
 
 38.894 
 
 36 
 
 37 
 
 7 
 
 9890. 75 
 
 68.68 
 
 53.98 
 
 532,52 
 
 4.157 
 
 .02574 
 
 .2413 
 
 38.850 
 
 37 
 
 38 
 
 8 
 
 10093.91 
 
 70.09 
 
 55.39 
 
 531.89 
 
 4 O68 
 
 .02578 
 
 .245!- 
 
 38.789 
 
 38 
 
 39 
 
 9 
 
 10300.88 
 
 71.53 
 
 56.83 
 
 531.26 
 
 3.989 
 
 02582 
 
 .2507 
 
 38.729 
 
 39 
 
 +40 
 
 500.66 
 
 10511.16 
 
 72.99 
 
 +68.29 
 
 530.63 
 
 3 915 
 
 .02586 
 
 .2554 
 
 38 684 
 
 +40 
 
 41 
 
 1 
 
 10724.95 
 
 74.48 
 
 59.78 
 
 529.99 
 
 3.839 
 
 .02588 
 
 .2606 
 
 38.639 
 
 41 
 
 42 
 
 2 
 
 10942.18 
 
 75.99 
 
 61.29 
 
 529.36 
 
 3.766 
 
 .02591 
 
 .2655 
 
 3S.595 
 
 42 
 
 43 
 
 3 
 
 11162.93 
 
 77.52 
 
 62.82 
 
 528.73 
 
 3.695 
 
 .02594 
 
 .2706 
 
 38.550 
 
 43 
 
 44 
 
 4 
 
 11387.21 
 
 79.08 
 
 64.38 
 
 528.10 
 
 3.627 
 
 .03597 
 
 .2757 
 
 33.499 
 
 4<J 
 
 +45 
 
 505.66 
 
 11615.12 
 
 80.66 
 
 +65.96 
 
 527.47 
 
 3 559 
 
 .0260( 
 
 .2809 
 
 38 461 
 
 +45 
 
 46 
 
 6 
 
 11846.64 
 
 82.27 
 
 67.5'i 
 
 526.83 
 
 3 493 
 
 02603 
 
 286* 
 
 38 41" 
 
 46 
 
 47 
 
 
 12081 80 
 
 83.90 
 
 69.20 
 
 526.20 
 
 3.428 
 
 .02606 
 
 .291" 
 
 38.373 
 
 47 
 
 41 
 
 8 
 
 12320.71 
 
 85.56 
 
 70.8fi 
 
 52557 
 
 3.362 
 
 .0^609 
 
 .2974 
 
 38.328 
 
 48 
 
 49 
 
 9 
 
 12563.36 
 
 87.2o 
 
 72.56 
 
 524 93 
 
 3 303 
 
 .02612 
 
 .302~ 
 
 38.284 
 
 49 
 
 4-50 
 
 510.66 
 
 12809.91 
 
 .88.96 
 
 +74.26 
 
 524 3( 
 
 3.242 
 
 .02616 
 
 .3084 
 
 38.22h 
 
 4-50 
 
 "' 5 
 
 1 
 
 13U80.21 
 
 90.7 
 
 76 OC 
 
 r>23 6h 
 
 3.182 
 
 .02620 
 
 .3143 
 
 38 167 
 
 51 
 
 52 
 
 2 
 
 13314.43 
 
 92.4 
 
 77 7f 
 
 >23 03 
 
 3 124 
 
 02623 
 
 3201 
 
 3 124 
 
 52 
 
 63 
 
 8 
 
 13572.52 
 
 94 2 
 
 79.55,522.39 
 
 3 069 
 
 0262fi 
 
 .3258 
 
 3* 080 
 
 53 
 
 54 
 
 4 
 
 13834.6 
 
 96.0 
 
 81.3?|521.7fi 
 
 3.012 
 
 .0262S 
 
 .3220 
 
 38 037 
 
 54 
 
162 
 
 MISCELLANEOUS TABLES. 
 
 PROPERTIES OF SATURATED AMMONIA. 
 
 CALCULATED FROM THE ORIGINAL FORMULA OF PROF. DE 
 VOLSON WOOD, BY GEORGE DAVIDSON, M.E. 
 
 Computed especially for and originally published in Ice and Refriger- 
 ation for December, 1894. 
 
 Tempera- 
 
 Pressure, 
 
 g a> 
 
 g* 3 
 
 5 
 
 Si 
 
 S 
 
 -$ 
 
 
 ture. 
 
 Absolute. 
 
 * 
 
 || 
 
 M 
 
 JP. 
 
 2p 
 
 "j </3 *J 
 
 ' 8? 
 
 
 
 
 
 hi 
 
 
 t 
 
 " 
 
 O Q< 
 
 ^EH^ 
 
 $ 
 
 ** D+^ 
 
 >a3 
 
 '-'ac 
 .^_ c o 
 
 P 
 
 *~ ' 
 
 CO 
 
 9 
 
 i 
 
 !* 
 
 |l 
 
 %* 
 
 *"% . 
 
 **J 
 
 la* 
 
 M 
 
 !r 
 
 ||s 
 
 & 
 
 f 
 
 1 
 
 |* 
 
 
 
 Ill 
 
 o 
 
 p 
 
 11 
 1 
 
 in 
 
 III 
 
 S.5w> 
 
 Stt 
 
 +65 
 
 515.66 
 
 14100.74 
 
 97.92 
 
 +83.22 
 
 521.12 
 
 2.958 
 
 .02632 
 
 3380 
 
 37.994 
 
 +55 
 
 6 
 
 6 
 
 14370.92 
 
 99.80 
 
 85.10 
 
 520.48 
 
 2.905 
 
 .02630 
 
 .344237.936 
 
 rxj 
 
 57 
 
 7 
 
 14645.18 
 
 101.70 
 
 87.00 
 
 519.84 
 
 2.853 
 
 .02639 
 
 .3505 
 
 37.893 
 
 57 
 
 58 
 
 8 
 
 14923.98 
 
 103.64 
 
 88.94 
 
 519.20 
 
 2.802 
 
 .02643 
 
 . 3568 
 
 07.835 
 
 
 59 
 
 9 
 
 15206.28 
 
 105.60 
 
 90.90 
 
 618.57 
 
 2.753 
 
 .02646 
 
 .3632 
 
 37.793 
 
 59 
 
 +60 
 
 520.66 
 
 15493.09 
 
 107.59 
 
 +92.89 
 
 517.93 
 
 2.705 
 
 .02651 
 
 .3697 
 
 37.736 
 
 +60 
 
 61 
 
 1 
 
 15784.23 
 
 109.61 
 
 94.91 
 
 517.29 
 
 2.658 
 
 .02654 
 
 .3762 
 
 37.678 
 
 61 
 
 62 
 
 2 
 
 16079.67 
 
 111.66 
 
 96.96 
 
 516.65 
 
 2.610 
 
 .02C58 
 
 .3831 
 
 37.622 
 
 62 
 
 63 
 
 3 
 
 16379.51 
 
 113.75 
 
 99.05 
 
 516.01 
 
 2.565 
 
 .02661 
 
 .3898 
 
 37.579 
 
 63 
 
 64 
 
 4 
 
 16683.76 
 
 115.86 
 
 101.16 
 
 515.37 
 
 2.520 
 
 .02665 
 
 .39(58 
 
 37.523 
 
 64 
 
 +65 
 
 525.66 
 
 16992.50 
 
 118.03 
 
 +103.33 
 
 514.73 
 
 2.476 
 
 .02668 
 
 .4039 
 
 37.481 
 
 +65 
 
 66 
 
 6 
 
 17305.70 
 
 120. 18 
 
 105.48 
 
 514.09 
 
 2.433 
 
 .026711.4110 
 
 37.43M 
 
 
 67 
 
 7 
 
 17623.45 
 
 122.38 
 
 107.68 
 
 513.45 
 
 2.389 
 
 .02675.4189 
 
 37.383 
 
 67 
 
 68 
 
 8 
 
 17946.89 
 
 124.62 
 
 109.92 
 
 512.81 
 
 2.351 
 
 .02678 
 
 .4254 
 
 37.341 
 
 (is 
 
 69 
 
 9 
 
 18272.81 
 
 126.89 
 
 112.19 
 
 512.16 
 
 2.310 
 
 .02682 
 
 .4329 
 
 37.285 
 
 69 
 
 +70 
 
 530.66 
 
 18604.53 
 
 129.19 
 
 +114.49 
 
 511.52 
 
 2.272 
 
 .02686 
 
 .4401 
 
 37.231 
 
 +70 
 
 71 
 
 1 
 
 18941.00 
 
 131.54 
 
 116.8* 
 
 510.87 
 
 2.233 
 
 .02689 
 
 .4479 
 
 37.188 
 
 71 
 
 72 
 
 2 
 
 19282.21 
 
 133.90 
 
 119.20 
 
 510.22 
 
 2.194 
 
 .02693 
 
 .4558 
 
 37.133 
 
 72 
 
 73 
 
 3 
 
 19628.32 
 
 136.31 
 
 121.61 
 
 509.58 
 
 2.153 
 
 .02697 
 
 .4645 
 
 37.079 
 
 73 
 
 74 
 
 4 
 
 19979.22 
 
 138.74 
 
 124.04 
 
 508.93 
 
 2.122 
 
 .02700 
 
 .4712 
 
 37.037 
 
 74 
 
 +75 
 
 535.66 
 
 20335.16 
 
 141.22 
 
 +126. 52 
 
 508.29 
 
 2.087 
 
 .02703 
 
 .4791 
 
 36.995 
 
 +75 
 
 76 
 
 6 
 
 20696.00 
 
 143. 72 
 
 129.02 
 
 507.64 
 
 2.052 
 
 .027 
 
 .4873 
 
 36.954 
 
 76 
 
 77 
 
 7 
 
 21061.85 
 
 146.26 
 
 131.56 
 
 506.99 
 
 2.017 
 
 .02710 
 
 .4957 
 
 36.900 
 
 77 
 
 78 
 
 8 
 
 21432.82 
 
 148.84 
 
 134.14 
 
 506.34 
 
 1.995 
 
 02714 
 
 .5012 
 
 36.845 
 
 78 
 
 79 
 
 9 
 
 21808.85 
 
 151.45 
 
 136.76 
 
 605.69 
 
 1.952 
 
 02717 
 
 .5123 
 
 36.805 
 
 79 
 
 +80 
 
 510-66 
 
 .32190.15 
 
 154.10 
 
 +139.40 
 
 505.05 
 
 1.921 
 
 02721 
 
 .5205 
 
 36.751 
 
 +80 
 
 81 
 
 1 
 
 22576.51 
 
 166.78 
 
 142.08 
 
 504.40 
 
 1.889 
 
 02725 
 
 .5294 
 
 36.696 
 
 81 
 
 82 
 
 2 
 
 22968 '.88 
 
 159.50 
 
 144.80 
 
 503.75 
 
 1.858 
 
 02728 
 
 .5382 
 
 36.657 
 
 82 
 
 83 
 
 3 
 
 23365.38 
 
 162.26 
 
 147.56 
 
 503.10 
 
 1.827 
 
 02732 
 
 .5473 
 
 36.603 
 
 K3 
 
 84 
 
 4 
 
 23767.81 
 
 165.05 
 
 150.35 
 
 502.45 
 
 1.799 
 
 02736 
 
 .5558 
 
 36.549 
 
 84 
 
 +85 
 
 545.66 
 
 24175.61 
 
 167.88 
 
 +153.18 
 
 501.81 
 
 1.770 
 
 02739 
 
 .5649 
 
 36.509 
 
 +85 
 
 86 
 
 6 
 
 24588.92 
 
 170.75 
 
 156.05 
 
 501.15 
 
 1.741 
 
 02743 
 
 .5744 
 
 36.456 
 
 86 
 
 87 
 
 7 
 
 25007.80 
 
 173.66 
 
 158.96 
 
 500.50 
 
 1.714 
 
 02747 
 
 .5834 
 
 36.407 
 
 87 
 
 88 
 
 8 
 
 25432.16 
 
 176.61 
 
 161.91 
 
 499.85 
 
 1.687 
 
 02751 
 
 .5927 
 
 36.350 
 
 88 
 
 89 
 
 9 
 
 25862.14 
 
 179.69 
 
 164.89 
 
 *99.20 
 
 1.660 
 
 02754 
 
 .6024 
 
 36.311 
 
 89 
 
 +90 
 
 550.66 
 
 26297.88 
 
 182.62 
 
 +167.92 
 
 498.55 
 
 1.634 
 
 02758 
 
 .6120 
 
 36.258 
 
 +90 
 
 91 
 
 
 26739.88 
 
 185.69 
 
 170-99 
 
 97.89 
 
 1.608 
 
 02761 
 
 .6219 
 
 86.219 
 
 91 
 
 92 
 
 2 
 
 27186.56 
 
 188.79 
 
 174.09 
 
 497.24 
 
 1.5H3 
 
 02765 
 
 .6317 
 
 36.166 
 
 92 
 
 93 
 
 3 
 
 27639.43 
 
 191.94 
 
 177.24 
 
 496.59 
 
 1 .558 
 
 .02769 
 
 .6418 
 
 35.114 
 
 93 
 
 04 
 
 4 
 
 28098.26 
 
 195 13 
 
 180.43 
 
 95.94 
 
 1.534 
 
 .02772 
 
 6518 
 
 36.075 
 
 94 
 
 +95 
 
 555.66 
 
 28563.00 
 
 198. 35 
 
 + 183. (15 
 
 95". 29 
 
 1.510 
 
 .02776 
 
 6622 
 
 36.025? 
 
 +95 
 
 96 
 
 6 
 
 29033.86 
 
 201.62 
 
 186.92 
 
 94.63 
 
 1.486 
 
 .02780 
 
 6729 
 
 35 971 
 
 
 97 
 
 f 
 
 29510.69 
 
 204.94 
 
 190.24 
 
 93.97 
 
 1.463 
 
 02784 
 
 6835 
 
 55.919 
 
 97 
 
 98 
 
 8 
 
 9993.52 
 
 208.29 
 
 193.59 
 
 93.32 
 
 1.442 
 
 .02787 
 
 6934 
 
 35.881 
 
 98 
 
 99 
 
 9 
 
 {0482.52 
 
 211.68 
 
 196.98 
 
 92.66 
 
 419 
 
 .02791 
 
 7047 
 
 35.829 
 
 99" 
 
 MOO 
 
 560.60 
 
 W977.78 
 
 215.12 
 
 +200.42 
 
 92.01 
 
 .398 
 
 .02795 
 
 7153 
 
 35.778 
 
 + 100 
 
MISCELLANEOUS TABLES. 
 
 163 
 
 WOOD'S TABLE OF PROPERTIES OF SATUR- 
 ATED VAPOR OF AMMONIA. 
 
 Temperature 
 
 Pressure 
 
 i ' 
 
 
 == 
 
 o 
 
 o 
 
 W go 
 
 
 Absolute. 
 
 If 
 
 tJ 2 
 
 * CD 
 
 a r- 
 
 \- 
 
 X* '"D 
 
 
 
 
 
 S 
 
 || 
 
 I! 
 
 II 
 
 H<5 
 
 S'l 
 
 51 
 
 * . 
 
 f* 
 
 2 
 
 
 h 
 
 
 
 k 
 
 *^g 
 
 f| 
 
 "3 "5 
 
 s 
 
 * j0 
 
 o w 
 
 3 
 
 o| 
 
 
 
 a 
 
 a 
 
 ft 
 
 (3 
 
 
 2a> 
 
 S*^ 
 
 a~ 
 
 ^ * 
 
 I 
 
 I 
 
 2- 
 
 .s 
 
 1= 
 
 "*X3 
 
 ca 
 
 ll 
 
 ii 
 
 So 
 
 Q 
 
 ^ 
 
 H 
 
 i_3 
 
 tf 
 
 i 
 
 > 
 
 t> 
 
 ? 
 
 40 
 
 420.66 
 
 1540.9 
 
 10.69 
 
 579.67 
 
 48.23 
 
 531.44 
 
 24.37 
 
 .0234 
 
 0410 
 
 35 
 
 425.66 
 
 1773.6 
 
 12 31 
 
 576.69 
 
 48.48 
 
 528.21 
 
 21.29 
 
 .0236 
 
 .0467 
 
 30 
 
 430.66 
 
 2035.8 
 
 14.13 
 
 573.69 
 
 48.77 
 
 524.92 
 
 18.66 
 
 .0237 
 
 0535 
 
 - 25 
 
 435.66 
 
 2329.5 
 
 16.17 
 
 570.68 
 
 49 06 
 
 521.62 
 
 16.41 
 
 .0238 
 
 .0609 
 
 -20 
 
 440.66 
 
 2657.5 
 
 18.45 
 
 567.67 
 
 49.38 
 
 518.29 
 
 14.48 
 
 .0240 
 
 .0690 
 
 15 
 
 445.66 
 
 8022.5 
 
 20.99 
 
 564.64 
 
 49.67 
 
 514 97 
 
 12.81 
 
 0242 
 
 .0779 
 
 10 
 
 450.66 
 
 3428.0 
 
 23.77 
 
 561.61 
 
 49.99 
 
 511.62 
 
 11.36 
 
 .0243 
 
 .0878 
 
 5 
 
 455.66 
 
 3877.2 
 
 26.93 
 
 558.56 
 
 50.31 
 
 508.25 
 
 10.12 
 
 .0244 
 
 .0988 
 
 
 
 460.66 
 
 4373.5 
 
 30.37 
 
 555.50 
 
 50.68 
 
 504.82 
 
 9.04 
 
 0246 
 
 .1109 
 
 + 5 
 
 465.66 
 
 4920.5 
 
 34.17 
 
 552.43 
 
 50.84 
 
 501.59 
 
 8.06 
 
 0247 
 
 .1241 
 
 + 10 
 
 470.66 
 
 5622.2 
 
 38.55 
 
 549.35 
 
 51.13 
 
 498.22 
 
 7.23 
 
 0249 
 
 .1384 
 
 + 15 
 
 475.66 
 
 6182.4 
 
 42.93 
 
 546.26 
 
 61.33 
 
 494.93 
 
 9.49 
 
 .0250 
 
 .1540 
 
 + 20 
 
 480.66 
 
 6905.3 
 
 47.95 
 
 543.15 
 
 51.61 
 
 491.54 
 
 5.84 
 
 .0252 
 
 .1712 
 
 + 25 
 
 485.66 
 
 7695.2 
 
 53.43 
 
 540.03 
 
 51.80 
 
 488.23 
 
 5.26 
 
 .0253 
 
 .1901 
 
 + 30 
 
 490.66 
 
 8556.6 
 
 59.41 
 
 536.92 
 
 52.01 
 
 484.91 
 
 4 75 
 
 .0254 
 
 .2106 ' 
 
 + 35 
 
 495.66 
 
 9493.9 
 
 65.93 
 
 533.78 
 
 52.22 
 
 481.56 
 
 4.31 
 
 .0256 
 
 .2320 
 
 + 40 
 
 500.66 
 
 10512 
 
 73.00 
 
 530.63 
 
 52.42 
 
 478.21 
 
 3 91 
 
 .0257 
 
 .2583 
 
 + 45 
 
 505.66 
 
 11616 
 
 80.66 
 
 527.47 
 
 52.62 
 
 474.85 
 
 3.56 
 
 .0260 
 
 .2809 
 
 + 50 
 
 510.66 
 
 12811 
 
 88.96 
 
 524.30 
 
 52.82 
 
 471.48 
 
 3.25 
 
 .0260 
 
 .3109 
 
 + 55 
 
 515.66 
 
 14102 
 
 97.93 
 
 521.12 
 
 53.01 
 
 468.11 
 
 2.96 
 
 .0260 
 
 .3379 
 
 + 60 
 
 520.66 
 
 15494 
 
 107.60 
 
 517.93 
 
 53.21 
 
 464.72 
 
 2.70 
 
 .0265 
 
 .3704 
 
 + 65 
 
 525.66 
 
 16998 
 
 118.03 
 
 514.73 
 
 53.38 
 
 461.35 
 
 2 48 
 
 .0266 
 
 .4034 
 
 + 70 
 
 530.66 
 
 18605 
 
 129.21 
 
 511.52 
 
 53.57 
 
 457.85 
 
 2.27 
 
 .0268 
 
 .4405 
 
 + 75 
 
 535.66 
 
 20336 
 
 141.25 
 
 608.29 
 
 53.76 
 
 454.53 
 
 2 08 
 
 .0270 
 
 .4808 
 
 + FO 
 
 540.66 
 
 22192 
 
 154.11 
 
 504.66 
 
 53 96 
 
 450.70 
 
 1.91 
 
 .0272 
 
 .5262 
 
 + 85 
 
 545.66 
 
 24178 
 
 167.86 
 
 501 81 
 
 54,15 
 
 447 66 
 
 1.77 
 
 .0273 
 
 .5649 
 
 + 90 
 
 550.66 
 
 26300 
 
 182.8 
 
 498 ..11 
 
 54.28 
 
 443.83 
 
 1.64 
 
 .0274 
 
 .6098 
 
 + 95 
 
 555.66 
 
 28565 
 
 198.37 
 
 495.29 
 
 54.41 
 
 440.88 
 
 1.51 
 
 .0277 
 
 6622 
 
 +100 
 
 560.66 
 
 30980 
 
 215.14 
 
 491.50 
 
 54.54 
 
 436.06 
 
 1.39 
 
 .0271) 
 
 .7194 
 
 +105 
 
 565.66 
 
 33550 
 
 232.98 
 
 488.72 
 
 54.67 
 
 434.08 
 
 1.289 
 
 .0281 
 
 .7757 
 
 +110 
 
 570.66 
 
 36284 
 
 251.97 
 
 485.42 
 
 54.78 
 
 430.64 
 
 1.203 
 
 .0283 
 
 .8312 
 
 +115 
 
 575.66 
 
 39188 
 
 272.14 
 
 482.41 
 
 54.91 
 
 427.40 
 
 1.121 
 
 .0285 .8912 
 
 +120 
 
 580.66 
 
 42267 
 
 293.49 
 
 478.79 
 
 55.03 
 
 423.75 
 
 1.041 
 
 .0287 
 
 .9608 
 
 +125 
 + 130 
 
 585.66 
 590.66 
 
 45528 
 48978 
 
 316.16 
 340.42 
 
 475.45 
 472.11 
 
 55.09 
 65.16 
 
 420.39 
 416.94 
 
 .9699 
 .9051 
 
 0289)1.0310 
 .0291 1.1048 
 
 +135 
 
 595.66 
 
 52626 
 
 365.16 
 
 468.75 
 
 55.22 
 
 413.53 
 
 .8457 
 
 .02931.1824 
 
 +140 
 
 600.66 
 
 56483 
 
 392.22 
 
 465.39 
 
 55.29 
 
 410.09 
 
 .7910 
 
 .02951.2642 
 
 +145 
 
 605.66 
 
 60550 
 
 420.49 
 
 462.01 
 
 65.34 
 
 406.67 
 
 .7408 
 
 .0297 
 
 1.349? 
 
 +160 
 
 610. 6tf 
 
 64833 
 
 450.20 
 
 458.62 
 
 55.39 
 
 402.23 
 
 .6946 
 
 .0299 
 
 1.4396 
 
 +155 
 
 615.66 
 
 69341 
 
 481.54 
 
 455.22 
 
 55.43 
 
 399 79 
 
 .6511 
 
 0302I1.535S 
 
 + 160 
 
 620.66 
 
 71086 
 
 514.40 
 
 451.81 
 
 55.46 
 
 39R.H5 
 
 .6128 
 
 .0304 
 
 1.6318 
 
 +165 
 
 625.66 
 
 79071 
 
 549. 04 1 448.39 
 
 55.48 392.94 .5765 
 
 .0306 
 
 1.7344 
 
 Thfe critical pressure of ammonia is 115 atmospheres, the 
 critical temperature at 130 F. (Dewar), critical volume .00482 
 (calculated). 
 
164 
 
 MISCELLANEOUS TABLES. 
 
 TABLE OF AMMONIA GAS (SUPER-HEATED 
 VAPOR). TEMPERATURE IN DEGREES F. 
 
 11 
 
 
 
 5 
 
 10 
 
 15 
 
 20 
 
 25 
 
 30 
 
 35 
 
 40 
 
 45 
 
 No. of Cu. Ft., v, Approximately Contained in ILb. of Gas. 
 
 15 
 
 18.81 
 
 19.05 
 
 19.20 
 
 19.48 
 
 19.68 
 
 19.87 
 
 20.08 
 
 20.2520.544 
 
 20. 
 
 16 
 
 17.56 
 
 17.85 
 
 18.09 
 
 18.24 
 
 18.43 
 
 18.52 
 
 18.81 
 
 18.9019.20 
 
 19. 
 
 17 
 
 16.60 
 
 16.70 
 
 16.96 
 
 17.08 
 
 17.28 
 
 17.48 
 
 17.66 
 
 17.8518.09 
 
 18. 
 
 18 
 
 15.54 
 
 15; 84 
 
 15.93 
 
 16.12 
 
 16.32 
 
 16.51 
 
 16.70 
 
 16,8917.08 
 
 17. 
 
 19 
 
 14.78 
 
 14.97 
 
 15.18 
 
 15.26 
 
 15.45 
 
 15.64 
 
 15,84 
 
 15.93 
 
 16.12 
 
 10. 
 
 20 
 
 14.01 
 
 14.25 
 
 14.40 
 
 H.49 
 
 14. 6g 
 
 14.88 
 
 14.97 
 
 15.16 
 
 15.36 
 
 15. 
 
 21 
 
 13.34 
 
 13.53 
 
 13.63 
 
 13.82 
 
 14.01 
 
 14.11 
 
 14.30 
 
 14.40jl4.59 
 
 14. 
 
 22 
 
 12.76 
 
 12.86 
 
 13.05 
 
 13.15 
 
 1334 
 
 13.44 
 
 13.63 
 
 13.7213.92 
 
 14. 
 
 23 
 
 12.19 
 
 12.28 
 
 12.48 
 
 12.57 
 
 12.76 
 
 12 86 
 
 13.05 
 
 13.1513.34 
 
 13. 
 
 
 
 
 
 
 
 
 
 1 
 
 
 24 
 
 11.71 
 
 11.80 
 
 11.90 
 
 12.09 
 
 12.19 
 
 12.38 
 
 12.48 
 
 12.57jl2.76 
 
 12. 
 
 25 
 
 11.23 
 
 11.34 
 
 11.42 
 
 11.61 
 
 11. Til 11.80 
 
 11.90 
 
 12 0912.19 
 
 12. 
 
 26 
 
 10.75 
 
 10.84 
 
 11.04 
 
 11.13 
 
 11.23 
 
 11.32 
 
 11.62 
 
 11.6111.71 
 
 11. 
 
 27 
 
 10.36 
 
 10.46 
 
 10.56 
 
 10.75 
 
 10.84 
 
 10.94 
 
 11.01 
 
 11.2311.32 
 
 11. 
 
 2s 
 
 9.98 
 
 10.08 
 
 10.17 
 
 10.36 
 
 10.46 
 
 .10.56 
 
 10.65 
 
 10.75 
 
 10.84 
 
 10. 
 
 29 
 
 9.60 
 
 9.69 
 
 9.79 
 
 9.98 
 
 10.08 
 
 10.17 
 
 10.27 
 
 10.36 
 
 10.46 
 
 10. 
 
 30 
 
 9.2120 
 
 9.30 
 
 10.46 
 
 9.60 
 
 9.69 
 
 9.79 
 
 9.98 
 
 10.08 
 
 10.17 
 
 10. 
 
 31 
 
 8.84 
 
 9.12 
 
 9.21 
 
 9.31 
 
 9.40 
 
 9.50 
 
 9.60 
 
 9.69 
 
 9.KO 
 
 9. 
 
 32 
 
 
 8.83 
 
 8.93 
 
 9.02 
 
 9.12 
 
 .21 
 
 9.31 
 
 9.40 
 
 9.50 
 
 9. 
 
 33 
 
 
 8.54 
 
 8.64 
 
 8.73 
 
 8.83 
 
 8.91 
 
 9.02 
 
 9.11 
 
 9.21 
 
 9. 
 
 34 
 
 
 8.25 
 
 9.35 
 
 8.49 
 
 8.54 
 
 8.64 
 
 8.73 
 
 8.83 
 
 8.92 
 
 9. 
 
 35 
 
 
 
 8.16 
 
 8.25 
 
 8.35 
 
 8.44 
 
 8.54 
 
 8.64 
 
 8.64 
 
 8. 
 
 33 
 
 
 -. 
 
 7.87 
 
 7.96 
 
 8.06 
 
 8.16 
 
 8.2tf 
 
 8.35 
 
 8.44 
 
 8. 
 
 37 
 
 
 
 > 7.68 
 
 7.67 
 
 7.87 
 
 7.96 
 
 8.06 
 
 8.16 
 
 8.26 
 
 8. 
 
 38 
 
 
 
 7,48 
 
 7.58 
 
 7.68 
 
 7.77 
 
 7.77 
 
 7.8! 
 
 7.98 
 
 8. 
 
 3!) 
 
 
 
 
 7.39 
 
 7.48 
 
 7.48 
 
 7.58 
 
 7.68 
 
 7.77 
 
 7. 
 
 4(1 
 
 
 
 
 7.20 
 
 7.29 
 
 7.39 
 
 7.39 
 
 7.48 
 
 7.58 
 
 7. 
 
 41 
 
 
 
 
 
 7.00 
 
 7.10 
 
 7.20 
 
 7.20 
 
 7.29 
 
 7.39 
 
 7. 
 
 42 
 
 
 
 
 6.81 
 
 6.91 
 
 7.00 
 
 7.10 
 
 7.10 
 
 7.20 
 
 7'. 
 
 43 
 
 
 
 
 
 6.72 
 
 6.81 
 
 6.91 
 
 7.00 
 
 7.08 
 
 7. 
 
 44 
 
 
 
 
 
 6.52 
 
 6.62 
 
 6.72 
 
 6 81 
 
 6.91 
 
 
 45 
 
 
 
 
 
 6.43 
 
 6.52 
 
 6.62 
 
 6.62 
 
 6.72 
 
 6. 
 
 
 
 
 
 
 
 
 I 
 
 
MISCELLANEOUS TABLES. 
 
 165 
 
 TABLE SHOWING REFRIGERATING EFFECT OF ONE CUBIC 
 
 FOOT OF AMMONIA GAS AT DIFFERENT CONDENSER 
 AND SUCTION (BACK) PRESSURES IN B. T. UNITS. 
 
 o . 
 
 * 
 
 Temperature of the Liquid in Degrees F. 
 
 gfc 
 
 g s.S 
 
 65 70 75 80 85 90 95 100 105 
 
 D (U 
 
 1J? 
 
 
 -t-> be 
 
 W* 1 a! 
 
 $ a a 
 
 
 |c 
 
 Ifj 
 
 Corresp'g. Condenser Pressure (gauge), Ibs. per sq. in. 
 
 8 
 
 H 
 
 c^ 
 
 103 115 127 139 153 168 184 200 218 
 
 
 G. Pres. 
 
 
 
 
 
 
 
 
 
 
 27 
 
 1 
 
 27.30 
 
 27.01 
 
 26.73 
 
 26.44 
 
 26.16 
 
 25.87 
 
 25.59 
 
 25.30 
 
 25.02 
 
 20 
 
 4 
 
 33.74 
 
 33.40 
 
 33.04 
 
 32.70 
 
 32.34 
 
 31.99 
 
 31.64 
 
 31.30 
 
 30.94- 
 
 15 
 
 6 
 
 36.36 
 
 3B.48 
 
 36.10 
 
 35.72 
 
 35.34 
 
 34.96 
 
 34.58 
 
 34.20 
 
 33.82 
 
 10 
 
 9 
 
 42.28 
 
 41.84 
 
 41.41 
 
 40.97 
 
 40.54 
 
 40.10 
 
 39.67 
 
 39.23 
 
 38.80 
 
 5 
 
 13 
 
 48.31 
 
 47.81 
 
 47.32 
 
 46.82 
 
 46.33 
 
 45.83 
 
 45.34 
 
 44.84 
 
 44.35 
 
 
 
 16 
 
 54.88 
 
 54.32 
 
 53.76 
 
 53.20 
 
 52.64 
 
 52.08 
 
 51.52 
 
 50.96 
 
 50 40 
 
 5 
 
 20 
 
 61.50 
 
 60.87 
 
 60.25 
 
 59.62 
 
 59.00 
 
 58.37 
 
 57.75 
 
 57.12 
 
 56.60 
 
 10 
 
 24 
 
 68.66 
 
 67.97 
 
 67.27 
 
 66.58 
 
 65.88 
 
 65.19 
 
 64.49 
 
 63.80 
 
 83.10 
 
 15 
 
 28 
 
 75.88 
 
 75.12 
 
 74.35 
 
 73.59 
 
 72.82 
 
 72.06 
 
 71.29 
 
 70.53 
 
 69.76 
 
 20 
 
 33 
 
 85.15 
 
 84.30 
 
 83.44 
 
 82.59 
 
 81.73 
 
 80.88 
 
 80.02 
 
 79.17 
 
 78.31 
 
 25 
 
 39 
 
 95.50 
 
 94.54 
 
 93.59 
 
 92.63 
 
 91.68 
 
 90.72 
 
 89.97 
 
 88.81 
 
 87.86 
 
 30 
 
 45 
 
 106.21 
 
 105.15 
 
 104.09 
 
 103.03 
 
 101.97 
 
 100.91 
 
 99.85 
 
 98.79 
 
 97.73 
 
 35 
 
 51 
 
 115.69 114.54 123.39 
 
 112.24 
 
 111.09 
 
 109.94 
 
 108.79107.64 
 
 106.49 
 
 TABLE GIVING NUMBER OF CUBIC FEET OF GAS THAT MUST 
 
 BE PUMPED PER MINUTE AT DIFFERENT CONDENSER 
 
 AND SUCTION PRESSURES, TO PRODUCE ONE TON 
 
 OF REFRIGERATION IN TWENTY-FOUR HOURS. 
 
 
 
 
 Temperature of the Gas in Degrees F. 
 
 O . 
 
 v ^ * 
 
 
 
 q P .5 
 
 65 70 75 80 85 90 95 100 105 
 
 g| 
 
 II? 
 
 
 ft 
 
 f|| 
 
 Corresp'g. Condenser Pressure (gauge;, Ibs. per sq. in. 
 
 1" 
 
 l j 
 
 103 115 127 139 153 168 184 200 218 
 
 27 
 
 G. Pres. 
 
 7.22 
 
 7.3 
 
 7.37 
 
 7.46 
 
 7.54 
 
 7.62 
 
 7.70 
 
 7.79 
 
 7.88 
 
 20 
 
 4 
 
 5.84 
 
 5.9 
 
 5.96 
 
 6.03 
 
 6.09 
 
 6.16 
 
 6.23 
 
 6.30 
 
 6.43 
 
 15 
 
 6 
 
 5.35 
 
 5.4 
 
 5.46 
 
 5.52 
 
 5.58 
 
 5.64 
 
 5.70 
 
 5.77 
 
 5.83 
 
 -10 
 
 9 
 
 4.66 
 
 4.73 
 
 4.76 
 
 4.81 
 
 4.86 
 
 4.91 
 
 4.97 
 
 5.05 
 
 5.08 
 
 - 5 
 
 13 
 
 4.09 
 
 4.12 
 
 4.17 
 
 4.21 
 
 4.25 
 
 4.30 
 
 4.35 
 
 4.40 
 
 4.44 
 
 
 
 16 
 
 3.59 
 
 3.63 
 
 3.66 
 
 3.70 
 
 3.74 
 
 3.78 
 
 3.83 
 
 3.87 
 
 3.91 
 
 5 
 
 20 
 
 3.20 
 
 3.24 
 
 3.27 
 
 3.30 
 
 3.34 
 
 3.38 
 
 3.41 
 
 3.45 
 
 3.49 
 
 10 
 
 24 
 
 2.87 
 
 2.9 
 
 2.93 
 
 2.96 
 
 2 99 
 
 3.02 
 
 3.06 
 
 3.09 
 
 3.12 
 
 15 
 
 28 
 
 2.59 
 
 2.61 
 
 2.65 
 
 2.68 
 
 2.71 
 
 2.73 
 
 2.76 
 
 2.80 
 
 2.82 
 
 20 
 
 33 
 
 2.31 
 
 2.34 
 
 2.36 
 
 2.38 
 
 2.41 
 
 2.44 
 
 2.46 
 
 2.49 
 
 2.51 
 
 25 
 
 39 
 
 2.06 
 
 2.08 
 
 2.10 
 
 2.12 
 
 2.15 
 
 2.17 
 
 2.20 
 
 2.22 
 
 2.24 
 
 30 
 
 45 
 
 1.85 
 
 1.87 
 
 1.89 
 
 1.91 
 
 1.93 
 
 1.95 
 
 1.97 
 
 2.00 
 
 2.01 
 
 35 
 
 51 
 
 1.70 
 
 1.72 
 
 1.74 
 
 1.76 
 
 1.77 
 
 1.79 
 
 1.81 
 
 1.83 
 
 1.85 
 
166 MISCELLANEOUS TABLES. 
 
 ANHYDROUS AMMONIA. 
 
 Ammonia is a compound of one volume of 
 nitrogen with three volumes of hydrogen, and 
 is therefore represented by the chemical form- 
 ula NH 3 . It contains by weight 82.35 per cent 
 nitrogen and 17.65 per cent hydrogen. Its mole- 
 cular weight is 17. 
 
 Ammonia is a colorless gas possessing a very 
 characteristic pungent smell. It is much lighter 
 than air, having a specific gravity (air 1) of 0.586, 
 one liter of gas weighing, at the normal temper- 
 ature and pressure, 0.76193 grams. By mechan- 
 ical pressure and cooling, it is converted from 
 a gaseous to a liquid state (liquid anhydrous am- 
 monia) which boils under the ordinary atmos- 
 pheric pressure at 28 T 6 below zero, or 240^ 
 lower than the boiling point of water under the 
 same conditions. One pound of the liquid at 32 
 will occupy 21.017 cubic feet of space when 
 evaporated at the atmospheric pressure. The 
 specific heat of ammonia gas, as determined by 
 Regnault (capacity for heat), is 0.50836. Its 
 latent heat of evaporation is about 560 thermal 
 units at 32 Fahrenheit, at which temperature 
 one pound of the liquid, evaporated under a 
 pressure of fifteen pounds per square inch, will 
 occupy twenty-one cubic feet. 
 
 TESTING ANHYDROUS AMMONIA. 
 
 Usually ammonia manufacturers sell their 
 goods subject to the condition and agreement, 
 on the part of the purchaser, that a sample be 
 drawn from each cylinder upon arrival and sub- 
 jected to a test before emptying the contents, 
 
MISCELLANEOUS TABLES. 167 
 
 no reclamation being- allowed on account of de- 
 ficiency in quality or strength after a cylinder 
 has been emptied or partly emptied. Therefore 
 it is important that the consumer satisfy him- 
 self of the purity of the ammonia before drawing 
 off the contents of the cylinder. 
 
 EVAPORATION TEST. 
 
 Any dealer in chemical supplies will furnish 
 an 8-ounce, flat bottom, wide neck, Bohemian 
 glass boiling- flask (in case of breakag-e it is well 
 to have several of these). Fit in the neck a 
 stopper having- a ^-inch vent hole punctured 
 through for escape of the gas. Insert in this 
 hole a short g-lass tube. Procure a piece of 
 3/8-inch iron pipe, threaded at one end; bend the 
 pipe to such a shape that the threaded end can 
 be connected with the cylinder valve; put the 
 wrench on the valve of the cylinder and open 
 it gently; allow a little of the ammonia gas to 
 escape at first in order to purge the pipe and 
 valve, then draw into the test flask from 2^ to 
 4 ounces of the liquid ammonia. When this is 
 accomplished, remove the test flask at once, 
 and insert in the neck the stopper with vent 
 tube, then place it in such a position as will 
 allow a small stream of water to flow over the 
 sides of the flask. Under these conditions the 
 ammonia will boil quickly and soon evaporate. 
 Any residue remaining in the flask indicates 
 impurities. Care is necessary in drawing off 
 the sample, as a very little moisture in the test 
 flask or in the pipe, or a brief exposure to the 
 atmosphere, will at once affect it. 
 
 OF 
 
168 
 
 MISCELLANEOUS TABLES. 
 
 COMPARISONS OF THERMOMETER SCALES, SHOWING 
 RELATIVE INDICATIONS OF THE CELSIUS, FAHREN- 
 HEIT AND REAUMUR THERMOMETER SCALES. 
 
 In the United States and England the Fahrenheit scale is generally 
 used; in France and in all scientific investigations and treatises, the 
 Celsius scale is uniformly used; and in Germany the Reaumur scale is 
 the one generally adopted. 
 
 c. 
 
 F. 
 
 R. 
 
 C. 
 
 F. 
 
 R. 
 
 C. 
 
 F. 
 
 R. 
 
 100 
 
 212.0 
 
 80.0 
 
 53 
 
 127.4 
 
 42.4 
 
 6 
 
 42.8 
 
 4.<S 
 
 99 
 
 210.2 
 
 79.2 
 
 5'i 
 
 125.6 
 
 41.6 
 
 5 41.0 
 
 4.0 
 
 98 
 
 208.4 
 
 78.4 
 
 51 
 
 123.8 
 
 40.8 
 
 4 
 
 39.2 
 
 3.2 
 
 97 
 
 206.6 
 
 77.6 
 
 50 
 
 122.0 
 
 40.0 
 
 3 
 
 37.4 
 
 2.4 
 
 9i 
 
 204.8 
 
 76.8 
 
 49 
 
 120.2 
 
 39.2 
 
 2 
 
 35.6 
 
 lx.0 
 
 93 
 
 203.0 
 
 76.0 
 
 48 
 
 118.4 
 
 38.4 
 
 1 
 
 33.8 
 
 O.H 
 
 U 
 
 201.2 
 
 75.2 
 
 47 
 
 116.6 
 
 37.6 
 
 Zero 
 
 32.0 
 
 Zero 
 
 93 
 
 199.4 
 
 74.4 
 
 46 
 
 114.8 
 
 36.8 
 
 1 
 
 30.2 
 
 0.8 
 
 92 
 
 197.6 
 
 73.6 
 
 45 
 
 113.0 
 
 36.0 
 
 2 
 
 28.4 
 
 1.6 
 
 91 
 
 195.8 
 
 72.8 
 
 44 
 
 111.2 
 
 35.2 
 
 3 
 
 26.6 
 
 2.4 
 
 90 
 
 194.0 
 
 72.0 
 
 43 
 
 109.4 
 
 34.4 
 
 4 
 
 24.8 
 
 3.2 
 
 89 
 
 192.2 
 
 71.2 
 
 42 
 
 107-6 
 
 38.6 
 
 5 
 
 23.0 
 
 4.0 
 
 88 
 
 190.4 
 
 70.4 
 
 41 
 
 105.8 
 
 32.8 
 
 6 
 
 21.2 
 
 4.8 
 
 87 
 
 188.8 
 
 69.6 
 
 40 
 
 104.0 
 
 32.0 
 
 7 
 
 19.4 
 
 5.6 
 
 86 
 
 186.8 
 
 68.8 
 
 39 
 
 102.2 
 
 31.2 
 
 8 
 
 17.6 
 
 6.4 
 
 85 
 
 185.0 
 
 68.0 
 
 38 
 
 100.4 
 
 30.4 
 
 9 
 
 16.8 
 
 7.2 
 
 84 
 
 183.2 
 
 67.2 
 
 37 
 
 98.6 
 
 29.6 
 
 10 
 
 14.0 
 
 8.0 
 
 b3 
 
 181.4 
 
 66.4 
 
 36 
 
 6.8 
 
 28.8 
 
 11 
 
 12 2 
 
 8.8 
 
 82 
 
 179.6 
 
 65.6 
 
 36 
 
 95.0 
 
 28.0 
 
 12 
 
 10.4 
 
 9.6 
 
 81 
 
 177.8 
 
 64.8 
 
 34 
 
 93.2 
 
 27.2 
 
 13 
 
 8.6 
 
 10.4 
 
 80 
 
 176.0 
 
 64.0 
 
 33 
 
 91.4 
 
 26.4 
 
 14 
 
 6.8 
 
 11.2 
 
 79 
 
 174.2 
 
 63.2 
 
 32 
 
 89.6 
 
 25.6 
 
 15 
 
 5.0 
 
 12.0 
 
 78 
 
 172.4 
 
 62.4 
 
 31 
 
 87.8 
 
 24.8 
 
 16 
 
 3.2 
 
 12.8 
 
 77 
 
 170.6 
 
 61.6 
 
 30 
 
 86.0 
 
 24.0 
 
 17 
 
 1.4 
 
 13.6 
 
 76 
 
 168.8 
 
 60.8 
 
 29 
 
 84.2 
 
 23.2 18 
 
 
 14.4 
 
 75 
 
 167.0 
 
 60.0 
 
 28 
 
 82.4 
 
 22.4 19 
 
 2.2 
 
 15.2 
 
 74 
 
 165.2 
 
 59.2 
 
 27 
 
 80.6 
 
 21.6 20 
 
 4.0 
 
 lfl.0 
 
 73 
 
 163.4 
 
 58.4 
 
 26 
 
 78.8 
 
 20.8 ! 21 
 
 5.8 
 
 16.8 
 
 72 
 
 161.6 
 
 57.6 
 
 25 
 
 77.0 
 
 20.0 ! 22 
 
 7.6 
 
 17.6 
 
 71 
 
 159.8 
 
 56.8 
 
 24 
 
 75.2 
 
 19.2 23 
 
 9.4 
 
 18.4 
 
 70 
 
 158.0 
 
 56.0 
 
 23 
 
 73.4 
 
 18.4 || 24 
 
 11.2 
 
 19.2 
 
 69 
 
 156.2 
 
 55.2 
 
 22 
 
 71.6 
 
 17.6 25 
 
 13.0 
 
 20.0 
 
 68 
 
 154.4 
 
 54.4 
 
 21 
 
 69.8 
 
 16.8 ! 26 
 
 14.8 
 
 20.8 
 
 67 
 
 152.6 
 
 53.6 
 
 20 
 
 68.0 
 
 16.0 i 27 
 
 16 6 
 
 21.6 
 
 66 
 
 ISO. 8 
 
 52.8 
 
 19 
 
 66 2 
 
 15.2 ! 28 
 
 18.4 
 
 22.4 
 
 65 
 
 149.0 
 
 52.0 
 
 18 
 
 64.4 
 
 14.4 | 29 
 
 20.2 
 
 23.2 
 
 64 
 
 147.2 
 
 51.2 
 
 17 
 
 62.6 
 
 13.6 
 
 30 
 
 22.0 
 
 24.0 
 
 63 
 
 146.4 
 
 50.4 
 
 16 
 
 60.8 
 
 12.8 
 
 81 
 
 23.8 
 
 24. 8 
 
 62 
 
 143.6 
 
 49.6 
 
 15 
 
 59.0 
 
 12.0 
 
 32 
 
 25.6 
 
 25.6 
 
 61 
 
 141.8 
 
 48.8 
 
 14 
 
 57.2 
 
 11.2 II 33 
 
 27.4 
 
 26.4 
 
 60 
 
 140.0 
 
 48.0 
 
 13 
 
 .55.4 
 
 10.4 i 34 
 
 29.2 
 
 27.2 
 
 59 
 
 138.2 
 
 47.2 
 
 12 
 
 53.6 
 
 9.6 
 
 35 
 
 31.0 
 
 28.0 
 
 58 
 
 136.4 
 
 46.4 
 
 11 
 
 51.8 
 
 8.8 
 
 36 
 
 32.8 
 
 28.8 
 
 57 
 
 134.3 
 
 45.6 li 10 
 
 50.0 
 
 8.0 
 
 37 
 
 34.6 
 
 29.6 
 
 56 
 
 132.8 
 
 44.8 9 
 
 48.2 
 
 7.2 
 
 38 
 
 36.4 
 
 30.4 
 
 55 
 
 131.0 
 
 44.0 
 
 8 
 
 46.4 
 
 6.4 
 
 39 
 
 38.2 
 
 31.2 
 
 54 
 
 129.2 
 
 43.2 
 
 7 
 
 44.6 
 
 5.8 
 
 40 
 
 40.0 
 
 32.0 
 
MISCELLANEOUS TABLES. 
 
 169 
 
 MEAN PRESSURE OF DIAGRAM OF AMMONIA 
 COMPRESSOR. 
 
 Reprinted from the Catalogue of the De La Vergne Refrigerating 
 Machine Co. 
 
 Oi 4^ CO 
 
 Men CD 
 
 ... 
 
 tO M M g 3! 
 
 OO5CO COO54^ to <W 
 
 ? | 
 
 Condens 
 pera 
 
 Condense] 
 
 m 
 
 to i ' i 
 
 O O O 
 
 1 1 I 1 |l 
 
 MM tO g ^ 
 
 enoen oeno S- 
 ooo ooo pg. 
 
 er Tem- 
 ture. 
 
 Pressure. 
 
 4- 4- *- 
 O CO en 
 
 . _ 
 
 -4 I OO 
 
 ^. ^ _ _ __ _ 
 I O5 en 4^ tO M 
 
 05 
 
 L 
 
 en MO 
 
 bO 05 05 
 
 oooo 
 
 00004^ 
 
 -4 CD OO 4^ ^1 4^ 
 
 4* rfi. C5 O tO O5 
 
 'o 
 
 CO 
 
 ^' 
 
 -4 CO M 
 
 01 en en 
 to to to 
 
 Oi en 4^ 4^ 4^ 4^ 
 h- ' O CD 4 Oi CO 
 
 -4 
 
 ' 
 
 2 
 
 CO O5 4*- 
 0-40 
 
 -4 Oi M CO CO CD 
 
 cc O5 en oo oo M 
 
 
 
 K 
 
 O CD O 
 
 to ro en 
 
 en en en 
 'en '4> ^4 
 
 CO 4^ -4 
 
 en en en en 45>. *>. 
 en 4^ to o -4 05 
 
 4 M 4^ CO CD CO 
 O O5 tO CO O 4- 
 
 -4 
 
 to 
 
 4 
 
 OS 05 05 
 I M -4 
 
 o: 4* en 
 
 O5 O5 O5 
 
 to to ' 
 
 -4 tO I 1 
 
 en co co 
 
 Oi Oi en enC'irf^ 
 CD -4 en co o oo 
 
 oc oc o o * -4 
 
 
 
 co 
 
 CD 
 
 O5 O5 O5 
 -4 OO 00 
 
 O^ O5 O5 
 
 O5 O5 en en en en 
 CO i > 00 O5 CO M 
 
 GO 
 
 M 
 
 Oi CO 4i. 
 tO Oi 05 
 
 CD o en 
 
 OO tO M 
 
 O5 4i> CD tO *> tO 
 -4 O 4 Ol O CO 
 
 O 
 
 CO 
 
 -4 -J -a 
 
 4-4-4- 
 
 CO I 1 CD 
 
 S 050 gencg 
 
 CD 
 
 M 
 
 %%Z 
 
 to oc oc 
 
 CO M05 
 
 81^ ^SS 
 
 
 
 OC 
 
 sbe 
 
 00 05 *- 
 4^ O5 tO 
 
 i O5 05 05 en en 
 t 1 oo en to oo os 
 
 O5 O5 Oi M OO M 
 tO tO CO O5 O5 M 
 
 1 
 
 2 
 
 ajgg 
 
 00 OO -4 
 CO i 00 
 
 4 4 05 05 05 en 
 
 en to oc en M oo 
 
 h- ' 
 
 r 
 
 -j CD en 
 
 0000 00 
 
 O5 CO Oi 
 
 OO CO CD 
 
 O5 tO OO t ' : Oi 
 M tO M 4^- O 4^ 
 
 O 
 
 p 
 
 CO CD CD 
 4- CO M 
 
 OC OO GO 
 OO O5 tO 
 
 4 4 *4 O5 O5 O5 
 
 CD Oi tO OO 4^ O 
 
 t * 
 
 to 
 
 en > > to 
 
 tO CD CD 
 
 CD ' CD 
 M OO -4 
 
 O5 OO O O O CD 
 I 1 4^ GO CO OO CD 
 
 I 
 
 00 
 
 (12) 
 
170 
 
 MISCELLANEOUS TABLES. 
 
 PROPERTIES OF SATURATED STEAM, 
 
 Total pressure 
 per 
 square inch. 
 
 Temperature 
 in Fahrenheit 
 degrees. 
 
 Total heat, 
 in Fahrenheit 
 degrees, from 
 water at 32 F. 
 
 Latent heat, 
 Fahrenheit 
 degrees. 
 
 Density, or 
 weight of one 
 cubic foot. 
 
 Volume of one 
 pound 
 of steam. 
 
 Relative vol- 
 ume or cubic 
 feet of steam 
 from one cubic 
 foot of water. 
 
 Lbs. 
 
 Fahr. 
 
 Fahr. 
 
 Fahr. 
 
 Lbs. 
 
 Cubic Feet 
 
 Rel. Vol. 
 
 1 
 
 102.1 
 
 1112.5 
 
 1042.9 
 
 .0030 
 
 330.36 
 
 20600 
 
 2 
 
 126.3 
 
 1119.7 
 
 1025.8 
 
 .0058 
 
 172.08 
 
 10730 
 
 3 
 
 141.6 
 
 1124.6 
 
 1015.0 
 
 .0085 
 
 117.52 
 
 7327 
 
 4 
 
 153.1 
 
 1128.1 
 
 1006.8 
 
 .0112 
 
 89.62 
 
 5589 
 
 5 
 
 162.3 
 
 1130.9 
 
 1000.3 
 
 .0138 
 
 72.66 
 
 4530 
 
 6 
 
 170.2 
 
 1133.3 
 
 994.7 
 
 .0168 
 
 61.21 
 
 3816 
 
 7 
 
 176.9 
 
 1135.3 
 
 990.0 
 
 .0189 
 
 52.94 
 
 3301 
 
 8 
 
 182.9 
 
 1137.2 
 
 985.7 
 
 .0214 
 
 46.69 
 
 2911 
 
 9 
 
 188.3 
 
 1138.8 
 
 981.9 
 
 .0239 
 
 41.79 
 
 2606 
 
 10 
 
 193.3 
 
 1140.3 
 
 978.4 
 
 .0264 
 
 37.84 
 
 2360 
 
 11 
 
 397.8 
 
 1141.7 
 
 975.2 
 
 .0289 
 
 34.63 
 
 2157 
 
 12 
 
 202.0 
 
 1143.0 
 
 972.2 
 
 .0314 
 
 31.88 
 
 1988 
 
 18 
 
 205.9 
 
 1144.2 
 
 969.4 
 
 .0338 
 
 29.57 
 
 1844 
 
 14 
 
 209.6 
 
 1145.3 
 
 966.8 
 
 .0362 
 
 27.61 
 
 1721 
 
 14.7 
 
 212.0 
 
 1146. 1 
 
 965.2 
 
 .0380 
 
 26.36 
 
 1642 
 
 15 
 
 213.1 
 
 1146.4 
 
 964.3 
 
 .0387 
 
 25.85 
 
 1611 
 
 16 
 
 216.3 
 
 1147.4 
 
 962.1 
 
 .0411 
 
 24.32 
 
 1516 
 
 J7 
 
 219.6 
 
 1148.3 
 
 959.8 
 
 .0435 
 
 22.96 
 
 1432 
 
 18 
 
 222.4 
 
 1149.2 
 
 957.7 
 
 .0459 
 
 21.78 
 
 1357 
 
 19 
 
 225.8 
 
 1150.1 
 
 955.7 
 
 .0483 
 
 20.70 
 
 1290 
 
 20 
 
 228.0 
 
 1150.9 
 
 952.8 
 
 .0507 
 
 19.72 
 
 1229 
 
 21 
 
 230.6 
 
 1151.7 
 
 951.3 
 
 .0531 
 
 18.84 
 
 1174 
 
 22 
 
 233.1 
 
 1152.5 
 
 949.9 
 
 .0555 
 
 18.03 
 
 1123 
 
 23 
 
 235.5 
 
 1153.2 
 
 948.5 
 
 .0580 
 
 17.26 
 
 1075 
 
 24 
 
 237.8 
 
 1153.9 
 
 946.9 
 
 .0601 
 
 16.64 
 
 1036 
 
 25 
 
 240.1 
 
 1154.6 
 
 945.3 
 
 .0625 
 
 15.99 
 
 996 
 
 26 
 
 242.3 
 
 1155.3 
 
 943.7 
 
 .0650 
 
 15.38 
 
 958 
 
 27 
 
 244.4 
 
 1155.8 
 
 942.2 
 
 .0673 
 
 14.86 
 
 926 
 
 28 
 
 246.4 
 
 1158.4 
 
 940.8 
 
 .0696 
 
 14.37 
 
 895 
 
 29 
 
 248.4 
 
 1157.1 
 
 939.4 
 
 .0719 
 
 13.90 
 
 866 
 
 30 
 
 250.4 
 
 1157.8 
 
 937.9 
 
 .0743 
 
 13.46 
 
 838 
 
 31 
 
 252.2 
 
 1158.4 
 
 936.7 
 
 .0766 
 
 13.05 
 
 813 
 
 32 
 
 254.1 
 
 1158.9 
 
 935.3 
 
 .0789 
 
 12.67 
 
 789 
 
 33 
 
 255.9 
 
 1159.6 
 
 934.0 
 
 .0812 
 
 12.31 
 
 767 
 
 34 
 
 257.6 
 
 1160.0 
 
 932.8 
 
 .0835 
 
 11. U7 
 
 74fl 
 
 35 
 
 259.3 
 
 1160.5 
 
 931.6 
 
 .0858 
 
 11.65 
 
 726 
 
 36 
 
 260.9 
 
 1161.0 
 
 930.5 
 
 .0881 
 
 11.34 
 
 707 
 
 37 
 
 262.6 
 
 1161.5 
 
 929.3 
 
 .0905 
 
 11.04 
 
 688 
 
 38 
 
 264.2 
 
 1162.0 
 
 928.2 
 
 .0929 
 
 10.76 
 
 671 
 
 39 
 
 265.8 
 
 1162.5 
 
 927.1 
 
 .0952 
 
 10.51 
 
 655 
 
 40 
 
 267.3 
 
 1162.9 
 
 926.0 
 
 .0974 
 
 10.27 
 
 640 
 
 41 
 
 268.7 
 
 1163.4 
 
 924.9 
 
 .0996 
 
 10.03 
 
 625 
 
 42 
 
 270.2 
 
 1163.8 
 
 923.9 
 
 .1020 
 
 9.81 
 
 611 
 
 43 
 
 271.6 
 
 1164.2 
 
 922.9 
 
 .1042 
 
 9.59 
 
 698 
 
 44 
 
 273.0 
 
 1164.6 
 
 921.9 
 
 .1065 
 
 9.39 
 
 585 
 
 45 
 
 274.4 
 
 1165.1 
 
 920.9 
 
 .1089 
 
 9.18 
 
 572 
 
 40 
 
 275.8 
 
 1165.5 
 
 919.9 
 
 .1111 
 
 9.00 
 
 561 
 
 47 
 
 277.1 
 
 1165.9 
 
 919.0 
 
 .1133 
 
 8.82 
 
 550 
 
 48 
 
 278.4 
 
 1166.3 
 
 918.1 
 
 .1156 
 
 8.65 
 
 539 
 
 49 
 
 279.7 
 
 1166.7 
 
 917.2 
 
 .1179 
 
 8.48 
 
 529 
 
 50 
 
 281.0 
 
 1167.1 
 
 916.3 
 
 .1202 
 
 8.31 
 
 518 
 
 51 
 
 282.3 
 
 1167.5 
 
 915.4 
 
 .1224 
 
 8.17 
 
 509 
 
 62 
 
 283.5 
 
 1167.9 
 
 914.5 
 
 .1246 
 
 8.04 
 
 500 
 
 53 
 
 284.7 
 
 1168.3 
 
 913.6 
 
 .1269 
 
 7.88 
 
 491 
 
 54 
 
 285.9 
 
 1168.6 
 
 912.8 
 
 .1291 
 
 7.74 
 
 482 
 
 55 
 
 287.1 
 
 1169.0 
 
 912.0 
 
 .1314 
 
 7.61 
 
 474 
 
 66 
 
 288.2 
 
 1169.3 
 
 911.2 
 
 .1336 
 
 7.48 
 
 466 
 
MISCELLANKOUS TABLES. 
 
 171 
 
 PROPERTIES OF SATURATED STEAM. CONT. 
 
 Total pressure 
 per 
 square inch, j 
 
 Temperature 
 in Fahrenheit 
 degrees. 
 
 Total heat, 
 in Fahrenheit 
 degrees, from 
 water at 32 F. 
 
 Latent heat, 
 Fahrenheit 
 degrees. 
 
 i 
 Density, or 
 weight of one 
 cubic foot. 
 
 Volume of one 
 pound 
 of steam. 
 
 Relative vol- 
 ume or cubic 
 feet of steam 
 from one cubic 
 foot of water. 
 
 Lbs. 
 
 Fahr. 
 
 Fahr. 
 
 Fahr. 
 
 Lbs. 
 
 Cubic Feet 
 
 Rel. Vol. 
 
 57 
 
 289.3 
 
 1169.7 
 
 910.4 
 
 .1364 
 
 7.38 
 
 458 
 
 68 
 
 290.4 
 
 1170.0 
 
 909.6 
 
 .1380 
 
 7.24 
 
 451 
 
 59 
 
 291.6 
 
 1170.4 
 
 908.8 
 
 .1403 
 
 7.12 
 
 444 
 
 60 
 
 292.7 
 
 1170.7 
 
 908.0 
 
 .1425 
 
 7.01 
 
 437 
 
 61 
 
 293.8 
 
 1171.1 
 
 907.2 
 
 .1447 
 
 6.90 
 
 430 
 
 62 
 
 204.3 
 
 1171.4 
 
 906.4 
 
 .1469 
 
 6.81 
 
 424 
 
 63 
 
 295.9 
 
 1171.7 
 
 905.6 
 
 .1493 
 
 6.70 
 
 417 
 
 64 
 
 296.9 
 
 1172.0 
 
 904.9 
 
 .1516 
 
 6.60 
 
 411 
 
 65 
 
 298.0 
 
 1172.3 
 
 904.2 
 
 .1538 
 
 6.49 
 
 405 - 
 
 66 
 
 299.0 
 
 1172.6 
 
 903.5 
 
 .1560 
 
 6.41 
 
 399 
 
 67 
 
 300.0 
 
 1172.9 
 
 902.8 
 
 .1583 
 
 6.32 
 
 393 
 
 68 
 
 300.9 
 
 1173.2 
 
 902.1 
 
 .1605 
 
 6.23 
 
 388 
 
 69 
 
 301.9 
 
 1173.5 
 
 901.4 
 
 .1627 
 
 6.15 
 
 383 
 
 70 
 
 302.9 
 
 1173.8 
 
 900.8 
 
 .1648 
 
 6.07 
 
 378 
 
 71 
 
 303.9 
 
 1174.1 
 
 900.3 
 
 .1670 
 
 5.99 
 
 373 
 
 72 
 
 304.8 
 
 1174.3 
 
 899.6 
 
 .1692 
 
 5.91 
 
 368 
 
 73 
 
 305.7 
 
 1174.6 
 
 898.9 
 
 .1714 
 
 5.83 
 
 363 
 
 74 
 
 306.6 
 
 1174.9 
 
 898.2 
 
 .1736 
 
 5.75 
 
 359 
 
 75 
 
 307.5 
 
 1175.2 
 
 897.5 
 
 .1759 
 
 5.68 
 
 353 
 
 76 
 
 308.4 
 
 1175.4 
 
 896.8 
 
 .1782 
 
 5.61 
 
 349 
 
 77 
 
 309.3 
 
 1175.7 
 
 896.1 
 
 .1804 
 
 5.54 
 
 345 
 
 78 
 
 310.2 
 
 1176.0 
 
 895.5 
 
 .1826 
 
 5.48 
 
 341 
 
 79 
 
 311.1 
 
 1176.3 
 
 894.9 
 
 .1848 
 
 5.41 
 
 337 
 
 80 
 
 312.0 
 
 1176.5 
 
 894.3 
 
 .1869 
 
 5.35 
 
 333 
 
 81 
 
 312.8 
 
 1176.8 
 
 893.7 
 
 .1891 
 
 5.29 
 
 329 
 
 82 
 
 313.6 
 
 1177.1 
 
 893.1 
 
 .1913 
 
 5.23 
 
 325 
 
 83 
 
 314.5 
 
 1177.4 
 
 892.5 
 
 .1935 
 
 5.17 
 
 321 
 
 84 
 
 315.3 
 
 1177.6 
 
 892.0 
 
 .1957 
 
 5.11 
 
 318 
 
 85 
 
 316.1 
 
 1177.9 
 
 891.4 
 
 .1980 
 
 5.05 
 
 314 
 
 86 
 
 316.9 
 
 1178.1 
 
 890.8 
 
 .2002 
 
 5.00 
 
 311 
 
 87 
 
 317.8 
 
 1178.4 
 
 890.2 
 
 .2024 
 
 4.94 
 
 308 
 
 88 
 
 318.6 
 
 1178.6 
 
 889.6 
 
 .2044 
 
 4.89 
 
 305 
 
 89 
 
 319.4 
 
 1178.9 
 
 889.0 
 
 .2067 
 
 4.84 
 
 301 
 
 90 
 
 320.2 
 
 1179.1 
 
 888.5 
 
 .2089 
 
 4.79 
 
 298 
 
 91 
 
 321.0 
 
 1179.3 
 
 887.9 
 
 .2111 
 
 4.74 
 
 295 
 
 92 
 
 321.7 
 
 1179.6 
 
 887.3 
 
 .2133 
 
 4.69 
 
 292 
 
 93 
 
 322.5 
 
 1179.8 
 
 886.8 
 
 .2155 
 
 4.64 
 
 289 
 
 94 
 
 323.3 
 
 1180.0 
 
 886 3 
 
 .2176 
 
 4.60 
 
 288 
 
 95 
 
 324.1 
 
 1180.3 
 
 886 8 
 
 .2198 
 
 4.56 
 
 283 
 
 96 
 
 324.8 
 
 1180.5 
 
 885.2 
 
 .2219 
 
 4.51 
 
 281 
 
 97 
 
 325.6 
 
 1180.8 
 
 884.6 
 
 .2241 
 
 4.46 
 
 278 
 
 98 
 
 326.3 
 
 1181.0 
 
 884.1 
 
 .2263 
 
 4.42 
 
 275 
 
 99 
 
 327.1 
 
 1181.2 
 
 883.6 
 
 .2285 
 
 4.37 
 
 272 
 
 100 
 
 327.9 
 
 1181.4 
 
 883 1 
 
 .2307 
 
 4.33 
 
 270 
 
 101 
 
 328.5 
 
 1181.6 
 
 882.6 
 
 .2329 
 
 4.29 
 
 267 
 
 102 
 
 329.1 
 
 1181.8 
 
 882 1 
 
 .2351 
 
 4.25 
 
 265 
 
 103 
 
 329.9 
 
 1182.0 
 
 881.6 
 
 .2373 
 
 4.21 
 
 262 
 
 104 
 
 330.6 
 
 1182.2 
 
 881 1 
 
 .2393 
 
 4.18 
 
 20 
 
 105 
 
 331.3 
 
 1182.4 
 
 880.7 
 
 .2414 ! 4.14 
 
 287 
 
 106 
 
 331.9 
 
 1182.6 
 
 880 2 
 
 .2435 ' 4.11 
 
 255 
 
 107 
 
 332.6 
 
 1182.8 
 
 879.7 
 
 .2456 j 4.07 
 
 253 
 
 108 
 
 333.3 
 
 1183.0 
 
 879.2 
 
 .2477 1 4.04 
 
 251 
 
 109 
 
 334.0 
 
 1183.3 
 
 878 7 
 
 .2499 
 
 4.00 
 
 249 
 
 110 
 
 334.6 
 
 1183.5 
 
 878.3 
 
 .2521 
 
 3.97 
 
 ?47 
 
 111 
 
 335.3 
 
 1183.7 
 
 877.8 
 
 .2543 
 
 3.93 
 
 246 
 
 112 
 
 336.0 
 
 1183.9 
 
 877.3 
 
 .2564 
 
 3.90 
 
 243 
 
 113 
 
 336. 7 
 
 1184.1 
 
 876.8 
 
 .2586 
 
 3.86 
 
 241 
 
172 
 
 MISCELLANEOUS TABLES. 
 
 PROPERTIES OF SATURATED STEAM. CONT. 
 
 Total pressure]! 
 per 
 square inch. | 
 
 Temperature 
 in Fahrenheit 
 degrees. 
 
 Total heat, 
 in Fahrenheit 
 degrees, from 
 water at 32 F. 
 
 Latent heat, 
 Fahrenheit 
 degrees. 
 
 1 
 Density, or 
 weight of one 
 cubic foot. 
 
 Volume of one 
 pound 
 of steam. 
 
 mi 
 Kl! 
 
 Illll 
 
 Lbs. 
 
 Fahr. 
 
 Fahr. 
 
 Fahr. 
 
 Lbs. 
 
 Cubic Fest 
 
 Rel. Vol. 
 
 114 
 
 337.4 
 
 1184.3 
 
 876.3 
 
 .2607 
 
 3.&3 
 
 239 
 
 115 
 
 338.0 
 
 1184.5 
 
 875.9 
 
 .2628 
 
 3.80 
 
 237 
 
 116 
 
 338.6 
 
 1184.7 
 
 875.5 
 
 .2649 
 
 i.77 
 
 2*5 
 
 117 
 
 339.3 
 
 1164.9 
 
 875.0 
 
 .2652 
 
 3.74 
 
 2:w 
 
 118 
 
 339.9 
 
 1185.1 
 
 874.5 
 
 .2674 
 
 3.71 
 
 231 
 
 119 
 
 340.5 
 
 1185.3 
 
 874.1 
 
 .2696 
 
 3.68 
 
 229 
 
 120 
 
 341.1 
 
 1185.4 
 
 873.7 
 
 .2738 
 
 3.65 
 
 227 
 
 121 
 
 341.8 
 
 1185.6 
 
 873.2 
 
 .2759 
 
 3.62 
 
 225 
 
 122 
 
 342 4 
 
 1185.8 
 
 872.8 
 
 .2780 
 
 3.59 
 
 224 
 
 123 
 
 343.0 
 
 1186.0 
 
 872.3 
 
 .2801 
 
 3.56 
 
 2^2 
 
 124 
 
 343.6 
 
 1186.2 
 
 871.9 
 
 .2822 
 
 3.54 
 
 221 
 
 125 
 
 344.2 
 
 1186.4 
 
 871.5 
 
 .2845 
 
 3.51 
 
 219 
 
 126 
 
 344.8 
 
 1186.6 
 
 871.1 
 
 .2867 
 
 3.49 
 
 - I ' 
 
 127 
 
 345.4 
 
 1186.8 
 
 870.7 
 
 .2889 
 
 3.46 
 
 215 
 
 128 
 
 346.0 
 
 1186.9 
 
 870.2 
 
 .2911 
 
 3.44 
 
 214 
 
 129 
 
 346.6 
 
 1187.1 
 
 869.8 
 
 .2933 
 
 3.41 
 
 212 
 
 130 
 
 347.2 
 
 1187.3 
 
 8*0.4 
 
 .2955 
 
 3.38 
 
 211 
 
 131 
 
 347.8 
 
 1187.5 
 
 869.0 
 
 .2977 
 
 3.35 
 
 209 
 
 132 
 
 348.3 
 
 1187.6 
 
 868.6 
 
 .2999 
 
 3.33 
 
 20S 
 
 133 
 
 348.9 
 
 1187.8 
 
 868.2 
 
 .3020 
 
 3.31 
 
 206 
 
 134 
 
 349.5 
 
 1188.0 
 
 867.8 
 
 .3040 
 
 3.29 
 
 205 
 
 135 
 
 350.1 
 
 1188.2 
 
 867.4 
 
 .3060 
 
 3.27 
 
 203 
 
 136 
 
 K50.6 
 
 1188.3 
 
 867.0 
 
 .3080 
 
 3.25 
 
 202 
 
 137 
 
 351.2 
 
 1188.5 
 
 866.6 
 
 .3101 
 
 3.22 
 
 200 
 
 138 
 
 351.8 
 
 1188.7 
 
 866.2 
 
 .3121 
 
 3.20 
 
 199 
 
 139 
 
 352.4 
 
 1188.9 
 
 865.8 
 
 .3142 
 
 3.18 
 
 198 
 
 140 
 
 352.9 
 
 1189.0 
 
 865.4 
 
 .3162 
 
 3.16 
 
 197 
 
 141 
 
 353.5 
 
 1189.2 
 
 865.0 
 
 .3184 
 
 3.14 
 
 195 
 
 142 
 
 364.0 
 
 1189.4 
 
 864.6 
 
 .3206 
 
 3.12 
 
 194 
 
 143 
 
 354.5 
 
 1189.6 
 
 864.2 
 
 .3228 
 
 3.10 
 
 193 
 
 144 
 
 355.0 
 
 1189.7 
 
 863.9 
 
 .3250 
 
 3 08 
 
 102 
 
 145 
 
 355.6 
 
 1189.9 
 
 863.5 
 
 .3273 
 
 3.06 
 
 190 
 
 146 
 
 356.1 
 
 1190.0 
 
 863.1 
 
 .3294 
 
 3.04 
 
 189 
 
 147 
 
 356.7 
 
 1190.2 
 
 862.7 
 
 .3315 
 
 3.02 
 
 18.H 
 
 148 
 
 35T.2 
 
 1190.3 
 
 862.3 
 
 .3H36 
 
 3.00 
 
 187 
 
 149 
 
 357.8 
 
 1190.5 
 
 861.9 
 
 .3357 
 
 2.98 
 
 186 
 
 150 
 
 358.3 
 
 1190 7 
 
 861.5 
 
 .3377 
 
 2.96 
 
 184 
 
 155 
 
 361.0 
 
 1191.5 
 
 859.7 
 
 .3484 
 
 2.87 
 
 179 
 
 160 
 
 363.4 
 
 1192.2 
 
 857 9 
 
 .3590 
 
 2.79 
 
 174 
 
 165 
 
 366.0 
 
 1192.9 
 
 856.2 
 
 .3695 
 
 2.71 
 
 169 
 
 170 
 
 368.2 
 
 1193.7 
 
 854.5 
 
 .3798 
 
 2.63 
 
 164 
 
 175 
 
 370.8 
 
 1194.4 
 
 852.9 
 
 .3899 
 
 2.56 
 
 159 
 
 180 
 
 372.9 
 
 1195.1 
 
 851.3 
 
 .4009 
 
 2.49 
 
 155 
 
 185 
 
 375.3 
 
 1195.8 
 
 849.6 
 
 .4117 
 
 2.43 
 
 151 
 
 190 
 
 377.5 
 
 1196.5 
 
 848.0 
 
 .4222 
 
 8.37 
 
 14S 
 
 195 
 
 379.7 
 
 1197.2 
 
 846.5 
 
 .4327 
 
 2.31 
 
 144 
 
 200 
 
 381.7 
 
 1197.8 
 
 845.0 
 
 .4431 
 
 2.26 
 
 141 
 
 210 
 
 386.0 
 
 1199.1 
 
 841.9 
 
 .4634 
 
 2.16 
 
 135 
 
 220 
 
 389.9 
 
 1200.3 
 
 839.2 
 
 .4842 
 
 2.06 
 
 129 
 
 230 
 
 393.8 
 
 1201.5 
 
 836.4 
 
 .6052 
 
 .98 
 
 123 
 
 240 
 
 397.5 
 
 1202.6 
 
 833. 8 
 
 .5248 
 
 .90 
 
 119 
 
 250 
 
 401.1 
 
 1203.7 
 
 831.2 
 
 .5464 
 
 .83 
 
 114 
 
 260 
 
 404.5 
 
 1204.8 
 
 828.8 
 
 .56K9 
 
 .76 
 
 110 
 
 270 
 
 407.9 
 
 1205.8 
 
 826.4 
 
 .5868 
 
 .70 
 
 108 
 
 280 
 
 411.2 
 
 1206.8 
 
 824.1 
 
 .6081 
 
 .64 
 
 102 
 
 290 
 
 414.4 
 
 1207.8 
 
 821.8 
 
 .6273 
 
 .59 
 
 99 
 
 300 
 
 417.5 
 
 1208.7 
 
 819.6 
 
 .6486 
 
 .54 
 
 93 
 
MISCELLANEOUS TABLES. 
 
 173 
 
 MEAN EFFECTIVE PRESSURE OF DIAGRAM 
 OF STEAM CYLINDER. 
 
 
 
 $553313 BaSSSRStS 
 
 sis* 
 
 The M. E. P. for any initial pressure not given in the table can be found 
 by multiplying- the (absolute) given pressure by the M.E. P. per pound 
 of initial, as given in the third horizontal line of the table. 
 
174 
 
 MISCELLANEOUS TABLES. 
 
 HEAD OF WATER AND EQUIVALENT PRESS- 
 URE IN POUNDS PER SQUARE INCH. 
 
 II 
 
 
 
 d .5 
 rti; 
 
 w.s 
 
 
 
 ' C 4J 
 
 & 
 
 
 
 M.S 
 
 1 
 
 Id' 
 &* 
 
 
 
 1 
 
 0.43 
 
 ~41 
 
 17.75 
 
 81 
 
 35.08 
 
 121 
 
 52.41 
 
 161 
 
 69.74 
 
 2 
 
 0.86 
 
 42 
 
 18.19 
 
 82 
 
 35.52 
 
 122 
 
 52.84 
 
 162 
 
 70.17 
 
 3 
 
 1.30 
 
 43 
 
 18.62 
 
 83 
 
 35.95 
 
 >123 
 
 53.28 
 
 163 
 
 70.61 
 
 4 
 
 1.73 
 
 44 
 
 19.05 
 
 84 
 
 36.39 
 
 124 
 
 53.71 
 
 164 
 
 71.04 
 
 5 
 
 2.16 
 
 45 
 
 19.49 
 
 85 
 
 36.82 
 
 125 
 
 54.15 
 
 165 
 
 71.47 
 
 6 
 
 2.59 
 
 46 
 
 19.92 
 
 86 
 
 37.25 
 
 126 
 
 54.58 
 
 166 
 
 71.91 
 
 7 
 
 3.03 
 
 47 
 
 20.35 
 
 87 
 
 37.68 
 
 : 127 
 
 55.01 
 
 167 
 
 72.34 
 
 8 
 
 3.46 
 
 48 
 
 20.79 
 
 88 
 
 38.12 
 
 128 
 
 55.44 
 
 168 
 
 72.77 
 
 9 
 
 3.89 
 
 \ 49 
 
 21.22 ; 
 
 89 
 
 38.55; 129 
 
 55.88 
 
 169 
 
 73.20 
 
 10 
 
 4.33 
 
 50 
 
 21.65 
 
 90 
 
 39.98 
 
 130 
 
 56.31 
 
 170 
 
 73.64 
 
 11 
 
 4.76 
 
 51 
 
 22.09 
 
 91 
 
 39.42 
 
 131 
 
 56.74 
 
 171 
 
 74.07 
 
 12 
 
 5.20 
 
 52 
 
 22.52 
 
 92 
 
 39.85 
 
 132 
 
 57.18 
 
 172 
 
 74.50 
 
 13 
 
 5.63 
 
 53 
 
 22.95 
 
 93 
 
 40.28 
 
 133 
 
 57.61 
 
 173 
 
 74.94 
 
 14 
 
 6.06 
 
 54 
 
 23.39 
 
 94 
 
 40.72 
 
 134 
 
 58.04 
 
 174 
 
 75.37 
 
 15 
 
 6.49 
 
 55 
 
 23.82 
 
 95 
 
 41.15 
 
 135 
 
 58.48 
 
 175 
 
 75.80 
 
 16 
 
 6.93 
 
 56 
 
 24.26 
 
 96 
 
 41.58 
 
 136 
 
 58.91 
 
 176 
 
 76.23 
 
 17 
 
 7.36 
 
 57 
 
 24.69 
 
 97 
 
 42.01 
 
 137 
 
 59.34 
 
 177 
 
 76.67 
 
 18 
 
 7.79 
 
 58 
 
 25.12 
 
 98 
 
 42.45 
 
 138 
 
 59.77 
 
 178 
 
 77.10 
 
 19 
 
 8.22 
 
 59 
 
 25.55' 
 
 99 
 
 42.88 
 
 139 
 
 60.21 
 
 179 
 
 77.53 
 
 20 
 
 8.66 
 
 60 
 
 25.99 
 
 100 
 
 43.31 
 
 ,140 
 
 60.64 
 
 180 
 
 77.97 
 
 21 
 
 9.09 
 
 61 
 
 26.42: 
 
 101 
 
 43.75 
 
 141 
 
 61.07 
 
 181 
 
 78.40 
 
 22 
 
 9.53 
 
 62 
 
 26.85 
 
 102 
 
 44.18 
 
 142 
 
 61.51 
 
 182 
 
 78.84 
 
 23 
 
 9.96 
 
 63 
 
 27.29 
 
 103 
 
 44.61 
 
 143 
 
 61.94 
 
 183 
 
 79.27 
 
 24 
 
 10.39 
 
 64 
 
 27.72 
 
 104 
 
 45.05 
 
 144 
 
 62.37 
 
 184 
 
 79.70 
 
 25 
 
 10.82 
 
 65 
 
 28.15 1 
 
 105 
 
 45.48 
 
 145 
 
 62.81 
 
 185 
 
 80.14 
 
 26 
 
 11.26 
 
 66 
 
 28.58 
 
 106 
 
 45.91 
 
 ;146 
 
 63.24 
 
 186 
 
 80.57 
 
 27 
 
 11.69 
 
 67 
 
 29.02 
 
 107 
 
 46.34 
 
 147 
 
 63.67 
 
 187 
 
 81.00 
 
 28 
 
 12.12 
 
 68 
 
 29.45 
 
 108 
 
 46.78 
 
 148 
 
 64.10 
 
 188 
 
 81.43 
 
 29 
 
 12.55 
 
 69 
 
 29.88 
 
 109 
 
 47.21 
 
 149 
 
 64.54 
 
 189 
 
 81.87 
 
 30 
 
 12.99 
 
 70 
 
 30.32 
 
 110 
 
 47.64 
 
 150 
 
 64.97 
 
 190 
 
 82.30 
 
 31 
 
 13.42 
 
 71 
 
 30.75 
 
 111 
 
 48.08 
 
 151 
 
 65.49 
 
 191 
 
 82.77 
 
 32 
 
 13.86 
 
 72 
 
 31.18 
 
 112 
 
 48.51 
 
 152 
 
 65.84 
 
 192 
 
 83.13 
 
 33 
 
 14.29 
 
 73 
 
 31.62 l lll3 
 
 48.94 
 
 153 
 
 66.27 
 
 193 
 
 83.60 
 
 34 
 
 14.72 
 
 74 
 
 32.05 
 
 114 
 
 49.38 
 
 154 
 
 66.70 
 
 194 
 
 84.03 
 
 35 
 
 15.16 
 
 75 
 
 32.48 
 
 115 
 
 49.81 
 
 155 
 
 67.14 
 
 195 
 
 84.47 
 
 36 
 
 15.59 
 
 76 
 
 32.92 
 
 116 
 
 50.24 
 
 156 
 
 67.57 
 
 196 
 
 84.90 
 
 37 
 
 16.02 
 
 77 
 
 33.35 
 
 117 
 
 50.68 
 
 157 
 
 68.00 
 
 197 
 
 85.33 
 
 38 
 
 16.45 
 
 78 
 
 33.78 
 
 118 
 
 51.11 
 
 158 
 
 68.43 
 
 198 
 
 85.76 
 
 39 
 
 16.89 
 
 79 
 
 34.21 
 
 119 
 
 51.54 
 
 |159 
 
 68.87 
 
 199 
 
 86.20 
 
 40 
 
 17.32 
 
 80 
 
 34.65J 120 
 
 51.98 
 
 1160 
 
 69.31 
 
 200 
 
 86.63 
 
MISCELLANEOUS TABLES. 
 
 175 
 
 TABLE SHOWING PROPERTIES OF SOLUTION 
 OF SALT. 
 
 (Chloride of Sodium.) 
 
 Percentage 
 of Salt by M 
 Weig-ht. 
 
 Pounds of 
 Salt per 
 Gallon of w 
 Solution. 
 
 3 
 
 C !-> 
 "|? 
 
 Q$ rt 
 
 Weight per 
 Gallon at ^ 
 39 P.-4 C. 
 
 5 
 
 a o 
 
 |T 
 
 *!. 
 
 6 
 
 y 
 
 -^ 
 J) o) 
 
 W 
 
 Freezing- 
 Point, -a 
 Fahrenheit. 
 
 1 
 
 9 
 
 0.084 
 169 
 
 4 
 g 
 
 8.40 
 8 46 
 
 1.007 
 1 015 
 
 0.992 
 
 30.5 
 29 3 
 
 2 5 
 
 212 
 
 10 
 
 8 50 
 
 1 019 
 
 
 28 6 
 
 3 
 
 256 
 
 12 
 
 8 53 
 
 1 023 
 
 
 27 8 
 
 3 5 
 
 300 
 
 14 
 
 8 56 
 
 1 026 
 
 
 27 1 
 
 4 
 
 344 
 
 16 
 
 8 59 
 
 1 030 
 
 
 26 6 
 
 5 
 
 0.433 
 
 20 
 
 8.65 
 
 1.037 
 
 0.960 
 
 25.2 
 
 6 
 
 523 
 
 24 
 
 8 72 
 
 1 045 
 
 
 23 9 
 
 7 
 
 617 
 
 28 
 
 8 78 
 
 1 053 
 
 
 22 5 
 
 8 
 
 708 
 
 32 
 
 8 85 
 
 1 061 
 
 
 21 2 
 
 9 
 10 
 
 0.802 
 0.897 
 
 36 
 40 
 
 8.91 
 8.97 
 
 1.068 
 1.076 
 
 6 '.892 
 
 19.9 
 18.7 
 
 12 
 15 
 20 
 
 1.092 
 
 1.389 
 1.928 
 
 48 
 60 
 80 
 
 9.10 
 9.26 
 9.64 
 
 1.091 
 1.115 
 1.155 
 
 6 '.855 
 0.829 
 
 16.0 
 12.2 
 6.1 
 
 24 
 
 2 376 
 
 96 
 
 9 90 
 
 1 187 
 
 
 1 2 
 
 25 
 26 
 29 
 
 2.488 
 2.610 
 
 100 
 
 9.97 
 10.04 
 
 1.196 
 1.204 
 
 0.783 
 
 .5 
 1.1 
 
 4.7 
 
 To determine the weig-ht of one cubic foot of brine, multiply the values 
 given in column 4 by 7.48. 
 
 To determine the weig-ht of salt to one cubic foot of brine, multiply the 
 values given in column 2 by 7.48. 
 
 PROPERTIES OF SOLUTION OF CHLORIDE 
 OF CALCIUM. 
 
 Percentage 
 by Weight. 
 
 Specific 
 Heat. 
 
 Spec. Grav. 
 at 60 F. 
 
 Freezing 
 Point, 
 Degrees F. 
 
 Freezing Point, 
 Deg. Cels. 
 
 1 
 
 0.996 
 
 1.009 
 
 31 
 
 0.5 
 
 5 
 
 0.964 
 
 1.043 
 
 27.5 
 
 2.5 
 
 10 
 
 0.896 
 
 1.087 
 
 22 
 
 5.6 
 
 15 
 
 0.860 
 
 1.134 
 
 15 
 
 9.6 
 
 20 
 
 0.834 
 
 1.182 
 
 - 1.5 
 
 14.8 
 
 25 
 
 0.790 
 
 1.234 
 
 21.8 
 
 22.1 
 
176 
 
 MISCELLANEOUS TABLES. 
 
 DIAMETERS, AREAS AND CIRCUMFERENCES 
 OF CIRCLES. 
 
 Diam. | 
 Inches. 
 
 Circumf. 
 Inches. 
 
 I- 
 
 <s 
 
 ll 
 
 E^ ao 
 1 
 
 ^x; 
 
 i* 
 
 if 
 
 a "> 
 B <u 
 
 3Z 
 
 ^ ' 
 o> 
 
 QC 
 
 b G 
 b w 
 
 *& 
 
 QC 
 
 S 
 o 
 
 <ti 
 
 1 
 
 3.14159 
 
 0.78540 
 
 4 
 
 12.5664 
 
 12 566 
 
 8 
 
 25 1327 
 
 50.265 
 
 , jtj 
 
 3.3379.4 
 
 0.88664' 
 
 1*0 
 
 12.7627 
 
 12.962 
 
 '/8 
 
 25 5224 
 
 ;>1.849 
 
 1 '4 
 
 3.53429 
 
 0.99402 
 
 1 
 
 12.9591 
 
 13.364 
 
 *4 
 
 2f>. 91 8 1 
 
 53.456 
 
 ft 
 
 3.73064 
 
 .1076 
 
 , 3 * 
 
 13.1554 
 
 13.772 
 
 % 
 
 26.3108 
 
 56.0b8 
 
 
 3.92699 
 
 .2272 
 
 k 
 
 13.3518. 
 
 14.186 
 
 l /2 
 
 26.7035 
 
 56.746 
 
 i s l 
 
 4.12334 
 
 .3530 
 
 i 5 f, 
 
 13.5481 
 
 14.607 
 
 X 
 
 27.0962 
 
 58.426 
 
 x 
 
 4.31969 
 
 .4849 
 
 % 
 
 13.7445 
 
 15.033 
 
 % 
 
 27. 4889 
 
 60.132 
 
 1 6 
 
 4.51604 
 
 .6230 
 
 J 7 6 
 
 13.9408 
 
 15.466 
 
 
 27. f 816 
 
 61.862 
 
 Va 
 
 4.71239 
 
 .7671 
 
 K 
 
 14.1372 
 
 15.904 
 
 9 
 
 28.2743 
 
 63.617 
 
 ," 6 
 
 4.90874 
 
 .9175 
 
 ft 
 
 14.3335 
 
 16.349 
 
 H 
 
 28. 6670 
 
 65.397 
 
 % 
 
 5.10509 
 
 2.0739 
 
 % 
 
 14.5299 
 
 16.1-00 
 
 H 
 
 29.0597 
 
 67.201 
 
 U 
 
 5.30144 
 
 2.236C 
 
 {I 
 
 14.7^62 
 
 17.257 
 
 % 
 
 29.4624 
 
 69.029 
 
 a 4 
 
 5.49779 
 
 2.4053 
 
 
 
 14. 9226 
 
 17.721 
 
 % 
 
 29.8451 
 
 70.882 
 
 1 3 
 
 5.69414 
 
 2.5802 
 
 n 
 
 15.1189 
 
 18.190 
 
 % 
 
 30.2378 
 
 72.760 
 
 X 
 
 5.89049 
 
 2.7612 
 
 % 
 
 15.3153 
 
 18.665 
 
 % 
 
 30.6305 
 
 74.662 
 
 18 
 
 6.08684 
 
 2.9483 
 
 \i 
 
 15.5116 
 
 19.147 
 
 % 
 
 31.0232 
 
 76.689 
 
 2 
 
 6.2*319 
 
 3.1416 
 
 5 
 
 15.70PO 
 
 19 635 
 
 10 
 
 31 4159 
 
 78.540 
 
 ,!B 
 
 6.47953 
 
 3.3410 
 
 A 
 
 15.9043 
 
 20.129 
 
 y 
 
 32.2013 
 
 82.516 
 
 M 
 
 6.67588 
 
 3.546 
 
 % 
 
 16.1007 
 
 20.629 
 
 Yz 
 
 32.9*67 
 
 86.590 
 
 ft 
 
 6.87223 
 
 3.7583 
 
 A. 
 
 16.2970 
 
 21.135 
 
 \ 
 
 33.7721 
 
 90.763 
 
 J4 
 
 7.06858 
 
 3.9761 
 
 H 
 
 16.4934 
 
 21.648 
 
 11 
 
 3-4.5575 
 
 95.033 
 
 1 5 6 
 
 7.26493 
 
 4.2000 
 
 1*8 
 
 16.6897 
 
 22.166 
 
 1 A 
 
 35.3429 
 
 99.402 
 
 % 
 
 7.46128 
 
 4.4301 
 
 % 
 
 16.8861 
 
 22.6H1 
 
 
 
 36.1283 
 
 103.87 
 
 
 7.65763 
 
 4.6664 
 
 I 7 * 
 
 17.0824 
 
 23.221 
 
 K 
 
 36.9137 
 
 108.43 
 
 */2 
 
 7.85398 
 
 4.9087 
 
 K 
 
 17.2788 
 
 23.758 
 
 12 
 
 37.6991 
 
 113.10 
 
 1 9 8 
 
 8.05033 
 
 5.1572 
 
 : ! 9 8 
 
 17.4751 
 
 24.301 
 
 y* 
 
 38.4845 
 
 117.86 
 
 H 
 
 8.24668 
 
 5.4119 
 
 % 
 
 17.6715 
 
 24.850 
 
 % 
 
 39.2699 
 
 122.72 
 
 H 
 
 8.44303 
 
 5,6727 
 
 \l 
 
 17.8678 
 
 25.406 
 
 % 
 
 40.0563 
 
 127.68 
 
 \ 
 
 8.63938 
 
 5.9396 
 
 X 
 
 18.0642 
 
 25 967 
 
 13 
 
 40.8407 
 
 132.73 
 
 1* 
 
 8.83573 
 
 6.2126 
 
 tf 
 
 18.2605 
 
 26.535 
 
 H 
 
 il.6261 
 
 137.89 
 
 % 
 
 9.03208 
 
 6.4918 
 
 % 
 
 18.4569 
 
 27 .'109 
 
 V4 
 
 42.4115 
 
 143.14 
 
 11 
 
 9.22843 
 
 6.7771 
 
 18 
 
 18.6532 
 
 27.688 
 
 M 
 
 43.1969 
 
 148.49 
 
 3 
 
 9.424:8 
 
 7.0686 
 
 6 
 
 18.8496 
 
 28.274 
 
 14 
 
 43.9823 
 
 153.94 
 
 iVs 
 
 9.62113 
 
 7.3662 
 
 H 
 
 19.2423 
 
 29.465 
 
 y\ 
 
 44.7671 
 
 159.48 
 
 H- 
 
 9.81748 
 
 7.6699 
 
 H 
 
 19.6350 
 
 30.680 
 
 Vz 
 
 45.5531 
 
 165.13 
 
 > 3 6 
 
 10.0138 
 
 7.9798 
 
 % 
 
 20.0277 
 
 31.919 
 
 X 
 
 46.3385 
 
 170.87 
 
 H 
 
 10.2102 
 
 8.2958 
 
 1 A' 
 
 20.4204 
 
 33.183 
 
 15 
 
 47.1239 
 
 176.71 
 
 IB 
 
 10.4065 
 
 8.6179 
 
 % 
 
 20.8131 
 
 34.472 
 
 H 
 
 47.9'093 
 
 182.65 
 
 %' 
 
 10.P029 
 
 8.9462 
 
 % 
 
 21.2058 
 
 35.785 
 
 54 
 
 48.6947 
 
 188.69 
 
 1 ? R 
 
 10.7992 
 
 9.2806 
 
 % 
 
 21.5984 
 
 37.122 
 
 
 49.48D1 
 
 194.83 
 
 H 
 
 10.9956 
 
 9.6211 
 
 1 
 
 21.9911 
 
 38.485 
 
 16 
 
 50.2655 
 
 201.06 
 
 ft" 
 
 11.1919 
 
 9.9678 
 
 y* 
 
 22.3838 
 
 39.871 
 
 y* 
 
 51.0509 
 
 207.39 
 
 
 
 11.3883 
 
 10.321 
 
 M 
 
 22.7765 
 
 41.282 
 
 H 
 
 51.8363 
 
 213.82 
 
 Ji 
 
 11.5846 
 
 10.680 
 
 % 
 
 23.1692 
 
 42.718 
 
 \ 
 
 52.6217 
 
 220.35 
 
 % 
 
 11.7810 
 
 11.045 
 
 l /2 
 
 23.5619 
 
 44.179 
 
 17 
 
 53.4071 
 
 226.98 
 
 ia 
 
 I <> 
 
 11.9772 
 
 11.416 
 
 5jj 
 
 23.9546 
 
 45.664 
 
 k 
 
 54.1925 
 
 233.71 
 
 fe 
 
 12.1737 
 
 11.793 
 
 % 
 
 24.3473 
 
 47.173 
 
 l /2 
 
 54.9779 
 
 240.53 
 
 .18 
 
 12.3700 
 
 12.177 
 
 7 /9 
 
 24.7400 
 
 48.707 
 
 
 #5.7(533 
 
 247.45 
 
MISCELLANEOUS TABLES. 
 
 177 
 
 DIAMETERS, AREAS AND CIRCUMFERENCES 
 OF CIRCLES. CONTINUED. 
 
 a| 
 .2-3 
 
 Qfl 
 
 Circumt". 
 Inches. 
 
 1 
 
 ll 
 
 Diam. 
 Inches. 
 
 Circumf. 
 Inches. 
 
 > . 
 
 Diam. I 
 Inches. 
 
 Circumf. 
 Inches. 
 
 s 
 
 18 
 
 56.5487 
 
 254.47 
 
 J3 
 
 100 531 
 
 804 25 
 
 46 
 
 144.513 
 
 1661.9 
 
 
 57 3341 
 
 261.59 
 
 /4 
 
 101.316 
 
 816.86 
 
 /4 
 
 145.21)9 
 
 1680.0 
 
 H 
 
 58.1195 
 
 268 80 
 
 Yz 
 
 102.102 
 
 829.58 
 
 Yz 
 
 146 U84 
 
 1698.2 
 
 X 
 
 58.9049 
 
 276.12 
 
 % 
 
 102 887 
 
 842.39 
 
 3 4 
 
 146 86!) 
 
 1716 5 
 
 19 
 
 59.6903 
 
 283.53 
 
 33 
 
 103 673 
 
 855.30 
 
 47' ' 
 
 147 65.' 
 
 1734 9 
 
 
 60 47.37 
 
 291.04 
 
 
 104.458 
 
 868.31 
 
 /4 
 
 148.440 
 
 1753.5 
 
 Yz 
 
 61.2611 
 
 208.65 
 
 Yz 
 
 105 243 
 
 881.41 
 
 Yz 
 
 149.226 
 
 1772 J 
 
 % 
 
 62.0465 
 
 306'. 35 
 
 ?4 
 
 106.029 
 
 894.62 
 
 % 
 
 150.011 
 
 1790.8 
 
 20 
 
 62.8319 
 
 314.16 
 
 34 
 
 106.814 
 
 907.92 
 
 48 
 
 150.796 
 
 1809 6 
 
 
 63.6173 
 
 322.06 
 
 
 107.600 
 
 921.32 
 
 
 151.582 
 
 1828.5 
 
 Yz 
 
 64.4036 
 
 330.06 
 
 Yz 
 
 108.385 
 
 934.82 
 
 Yz 
 
 152.367 
 
 1847.5 
 
 "X 
 
 66.1830 
 
 338.16 
 
 % 
 
 109.170 
 
 948.42 
 
 % 
 
 153.153 
 
 1866.5 
 
 21 
 
 65.9734 
 
 346.36 
 
 35' 
 
 109.956 
 
 962.11 
 
 49 
 
 153.938 
 
 1885.7 
 
 
 66.7588 
 
 354.66 
 
 X 
 
 110.741 
 
 975.91 
 
 Y\ 
 
 154.723 
 
 1905.0 
 
 V 
 
 67.5442 
 
 363.05 
 
 Yz 
 
 111.627 
 
 989. 80 
 
 Yz 
 
 155.509 
 
 1924.2 
 
 X 
 
 68.3398 
 
 371.54 
 
 
 112.312 
 
 1003.8 
 
 $4. 
 
 156.294 
 
 1943.9 
 
 
 69.1150 
 
 380.13 
 
 36 4 
 
 113.097 
 
 1017.9 . 
 
 50 
 
 157.080 
 
 1963.5 
 
 1 
 
 69.9004 
 
 388.82 
 
 \2 
 
 113.883 
 
 1032.1 
 
 \i 
 
 157.865 
 
 1983.2 
 
 % 
 
 70.6858 
 
 397.61 
 
 % 
 
 114.668 
 
 1046.3 
 
 Yz 
 
 158.650 
 
 2003.0 
 
 ^ 
 
 71 4712 
 
 406.49 
 
 % 
 
 115.454 
 
 1060.7 
 
 
 159.436 
 
 2022.8 
 
 23 
 
 72.2566 
 
 415.48 
 
 3? 
 
 116.239 
 
 1075.2 
 
 51 4 
 
 160.221 
 
 2042.8 
 
 
 73.0420 
 
 424.56 
 
 Y 117.024 
 
 1089.8 
 
 
 161.007 
 
 2062.9 
 
 /4 
 
 73.8274 
 
 433.74 
 
 M 
 
 117.810 
 
 1104.5 
 
 Yz 
 
 161.792 
 
 2083.1 
 
 24 
 
 74.6128 
 
 443.01 
 
 X 
 
 118.596 
 
 1119.2 
 
 % 
 
 162 577 
 
 2103.3 
 
 24 
 
 75.3982 
 
 452.39 
 
 38 
 
 119.381 
 
 1134.1 
 
 52 
 
 163.363 
 
 2123.7 
 
 
 76.1836 
 
 461.86 
 
 X 
 
 120.166 
 
 1149.1 
 
 
 164.148 
 
 2144.2 
 
 ^2 
 
 76.9690 
 
 471.44 
 
 
 120.951 
 
 1164.2 
 
 ~" Yz 
 
 164.934 
 
 2164.8 
 
 Jj 
 
 77.7544 
 
 481.11 
 
 % 
 
 121.737 
 
 1179.3 
 
 % 
 
 165.719 
 
 2185.4 
 
 25 
 
 78.5398 
 
 490.87 
 
 39 
 
 122.522 
 
 1194.6 
 
 53 
 
 166.504 
 
 2206.2 
 
 \,' 
 
 79.3252 
 
 500.74 
 
 
 123.308 
 
 1310.0 
 
 J4 
 
 167.290 
 
 2227.0 
 
 Yt 
 
 80.1106 
 
 510.71 
 
 Yz 
 
 124.093 
 
 1225.4 
 
 Yz 
 
 168.075 
 
 2248.0 
 
 
 80.8960 
 
 620.77 
 
 
 124.878 
 
 1241.0 
 
 94 
 
 168.861 
 
 2269.1 
 
 26^ 
 
 81.6814 
 
 630.93 
 
 40 4 
 
 125.664 
 
 1266.6 
 
 54 
 
 169.. 646 
 
 2290.3 
 
 
 82.4668 
 
 541. 19 
 
 
 126.449 
 
 1272.4 
 
 
 170.431 
 
 2311.5 
 
 i^ 
 
 83.2522 
 
 551.55 
 
 y* 
 
 127.235 
 
 1288.2 
 
 Yz 
 
 171.217 
 
 2332.8 
 
 2 ' 
 
 84.0376 
 
 562.00 
 
 
 128.020 
 
 1304.2 
 
 
 172.002 
 
 2354.3 
 
 27* 
 
 84.8230 
 
 572.66 
 
 41 4 
 
 128.805 
 
 1320.3 
 
 55^ 
 
 172.788 
 
 2376.8 
 
 
 85.6084 
 
 583.21 
 
 
 129.591 
 
 1336.4 
 
 X 
 
 173.573 
 
 2397.5 
 
 Yt 
 
 86.3938 
 
 593.96 
 
 X 
 
 130.376 
 
 1352.7 
 
 
 174.358 
 
 2419.2 
 
 94 
 
 87.1792 
 
 604.81 
 
 94 
 
 131.161 
 
 1369.0 
 
 94 
 
 175.144 
 
 2441.1 
 
 28 
 
 87.9646 
 
 615.75 
 
 42 
 
 131.947 
 
 1385.4 
 
 56 
 
 175.929 
 
 2463.0 
 
 J4 
 
 88.7500 
 
 626.80 
 
 J4 
 
 132. 732 
 
 1402.0 
 
 
 176.715 
 
 2485.0 
 
 !4 
 
 89.5354 
 
 637.94 
 
 
 133.518 
 
 1418.6 
 
 4 
 
 177.500 
 
 2607.2 
 
 a^ 
 
 90.3208 
 
 649.18 
 
 24 
 
 134.303 
 
 1436.4 
 
 
 178.285 
 
 2529.4 
 
 29 
 
 91.1062 
 
 660.52 
 
 43- 
 
 135.088 
 
 1452.2 
 
 57 4 
 
 179.071 
 
 2551.8 
 
 /4 
 
 91.8916 
 
 671.96 
 
 i 
 
 135.874- 
 
 1469.1 
 
 /4 
 
 179.856 
 
 2574.2 
 
 Yz 
 
 92.67 r <0 
 
 683.49 
 
 Y 
 
 136.659 
 
 1486.2 
 
 y* 
 
 180.642 
 
 2596.7 
 
 % 
 
 93.4624 
 
 695.13 
 
 X 
 
 137 445 
 
 1503.3 
 
 24 
 
 181.427 
 
 2619.4 
 
 30 
 
 94.2478 
 
 706.86 
 
 44 
 
 138.230 
 
 1620.5 
 
 58 
 
 182.212 
 
 2642.1 
 
 
 95.0332 
 
 718.69 
 
 
 139.015 
 
 1537.9 
 
 i^ 
 
 182.998 
 
 2664.9 
 
 8 
 
 95.8186 
 
 730.62 
 
 Yz 
 
 139.801 
 
 1555.3 
 
 <y 
 
 183.783 
 
 2687.8 
 
 
 96.6040 
 
 742.64 
 
 94 
 
 140.586 
 
 1572.8 
 
 % 
 
 184.569 
 
 2710.9 
 
 31. 4 
 
 97.3894 
 
 754.77 
 
 45 
 
 141.372 
 
 1590.4 
 
 59 
 
 1&5.354 
 
 2734.0 
 
 
 98.1748 
 
 766.99 
 
 X 
 
 142.157 
 
 1608.2 
 
 
 186.139 
 
 2757.2 
 
 % 
 
 98.9602 
 
 779.31 
 
 Yz 
 
 142.942 
 
 1626.0 
 
 Yz 
 
 186.925 
 
 2780.5 
 
 % 
 
 99.7466 
 
 791.73 
 
 
 143.728 
 
 1643.9 
 
 % 
 
 187. 7JO 
 
 2803.9 
 
178 
 
 MISCELLANEOUS TABLES. 
 
 DIAMETERS, AREAS AND CIRCUMFERENCES 
 OF CIRCLES. CONTINUED. 
 
 rig 
 
 *H 
 
 g en 
 
 f3 
 
 at 
 
 ii 
 
 
 d 
 
 S 
 
 J 
 
 1 
 
 S 
 
 3,a 
 
 M 
 
 $? 
 
 ! 
 
 QC 
 
 XA 
 ^d 
 
 o" 
 
 
 ll 
 
 d.a 
 o o 
 ^a 
 O w 
 
 M 
 
 60 
 
 188.496 
 
 2827.4 
 
 74 
 
 232.478 
 
 4300.8 
 
 88 
 
 276.460 
 
 6082.1 
 
 % 
 
 189.281 
 
 2851.0 
 
 k. 
 
 233.263 
 
 4329.9 
 
 /4 
 
 277.246 
 
 6116.7 
 
 2 
 
 190.066 
 
 2874.8 
 
 
 234.049 
 
 4359.2 
 
 Y~ 
 
 278.031 
 
 6151.4 
 
 
 190.852 
 
 2898.6 
 
 5 
 
 234.834 
 
 4388.5 
 
 % 
 
 278.816 
 
 6186.2 
 
 61* 
 
 191.637 
 
 2922.5 
 
 75 
 
 235.619 
 
 4417.9 
 
 89 
 
 279.602 
 
 6221.1 
 
 
 192.423 
 
 2946.5 ! 
 
 
 236.405 
 
 4447.4 
 
 
 280.387 
 
 6256.1 
 
 'Yz 
 
 193.208 
 
 2970.6 
 
 y 2 
 
 237.190 
 
 4477,0 
 
 y?. 
 
 281.173 
 
 6291.2 
 
 % 
 
 193.993 
 
 2994:8 ! 
 
 % 
 
 237.976 
 
 4506.7 
 
 % 
 
 281.958 
 
 6326.4 
 
 i 
 
 194.779 
 
 3019.1 
 
 76 
 
 238.761 
 
 4536.5 
 
 90 
 
 282.743 
 
 6361.7 
 
 
 195.564 
 
 3043.5 
 
 y 
 
 239.546 
 
 4566.4 
 
 Ji 
 
 283.629 
 
 6397.1 
 
 Vt 
 
 196.35JU 
 
 3068.0 
 
 Yz 
 
 240.332 
 
 4596.3 
 
 Yt 
 
 284.314 
 
 6432.6 
 
 
 197.135 
 
 3092.6 
 
 
 241.117 
 
 4626.4 
 
 
 285.100 
 
 6468.2 
 
 63* 
 
 197.920 
 
 3117.2 
 
 77 
 
 241.903 
 
 4656.6 
 
 91* 
 
 288.885 
 
 6503.9 
 
 
 198.706 
 
 3142.0 
 
 /4 
 
 242. 688 
 
 4686.9 
 
 /4 
 
 286.670 
 
 6539.7 
 
 Yz 
 
 199.491 
 
 3166,9 
 
 Yz 
 
 243.473 
 
 4717.3 
 
 
 287.466 
 
 6575 5 
 
 
 200.277 
 
 3191.9 
 
 %. 
 
 244.259 
 
 4747.8 
 
 2i 
 
 288.241 
 
 6611.5 
 
 64 4 
 
 201.062 
 
 3217.0 
 
 78 
 
 245.044 
 
 4778.4 
 
 92 
 
 289.027 
 
 6647.6 
 
 
 201.847 
 
 3242.2 
 
 
 245.830 
 
 4809.0 
 
 
 289.812 
 
 6683.8 
 
 Yz 
 
 202.633 
 
 3267.5 
 
 Yz 
 
 246.615 
 
 4839.8 
 
 Yz 
 
 290.597 
 
 6720.1 
 
 % 
 
 203.418 
 
 3292.8 
 
 3L' 
 
 247.400 
 
 4870.7 
 
 M 
 
 291.383 
 
 6766.4 
 
 65 
 
 204.204 
 
 3318.? 
 
 79 
 
 248.186 
 
 4901.7 
 
 93 
 
 292.168 
 
 6792.9 
 
 
 204.989 
 
 3343.9 
 
 y*. 
 
 248.971 
 
 4932.7 
 
 /4 
 
 292.954 
 
 6829. 5 
 
 Yz 
 
 205.774 
 
 3369.6 
 
 y* 
 
 249.757 
 
 4963.9 
 
 Yz 
 
 293.739 
 
 6866.1 
 
 % 
 
 206.560 
 
 3395.3 
 
 
 250.542 
 
 4995.2 
 
 % 
 
 294.524 
 
 6902.9 
 
 66 
 
 207.345 
 
 3421.2 
 
 80*. 
 
 261.327 
 
 5026.5 
 
 94 
 
 295.310 
 
 6939.8 
 
 /4 
 
 208.131 
 
 3447.2 
 
 i> 
 
 252.113 
 
 5058.0 
 
 !/ 
 
 296.095 
 
 6976.7 
 
 V6 
 
 208.916 
 
 3473T2 
 
 H 
 
 252.898 
 
 5089.6 
 
 Yz 
 
 296.881 
 
 7013.8 
 
 9 
 
 209.701 
 
 3499.4 
 
 
 253.684 
 
 5121.2 
 
 % 
 
 297.666 
 
 7051.0 
 
 67 
 
 210.487 
 
 3526." 
 
 81* 
 
 254.469 
 
 5153.0 
 
 95 
 
 298.451 
 
 7088.2 
 
 /4 
 
 211.272 
 
 3552.0 
 
 H 
 
 255.254 
 
 5184.9 
 
 14 
 
 299.237 
 
 7125.6 
 
 i^ 
 
 212.058 
 
 3578.5 
 
 Yz 
 
 256.040 
 
 5216.8 
 
 i/ 
 
 300.022 
 
 7163.0 
 
 M 
 
 212.843 
 
 3605.0 
 
 
 256.825 
 
 5248.9 
 
 If 
 
 300.807 
 
 7200.6 
 
 68' 
 
 213.628 
 
 3631.7 
 
 82* 
 
 257.611 
 
 5281.0 
 
 96 
 
 301.593 
 
 7238.2 
 
 /4 
 
 214.414 
 
 3658.4 
 
 /4 
 
 258.396 
 
 5313.3 
 
 \A 
 
 302.378 
 
 7276.0 
 
 14 
 
 215.199 
 
 3685.3 
 
 Yz 
 
 259.181 
 
 5345.6 
 
 Yz 
 
 303.164 
 
 7313.8 
 
 3 i 
 
 215.984 
 
 3712.2 
 
 % 
 
 259.967 
 
 5378.1 
 
 
 303.949 
 
 7361.8 
 
 69 
 
 216.770 
 
 3739.3 
 
 83 
 
 260.752 
 
 5410.6 
 
 97 /4 
 
 304.734 
 
 7389.8 
 
 K 
 
 217.555 
 
 3766.4 
 
 y 
 
 261.538 
 
 5443.3 
 
 /4 
 
 305.520 
 
 7428.0 
 
 H 
 
 2I8.-341 
 
 3793-7 
 
 Yz 
 
 262.323 
 
 5^76 
 
 Yz 
 
 306.305 
 
 7466:2 
 
 
 219.126 
 
 3821.0 
 
 %. 
 
 263.108 
 
 5508.8 
 
 % 
 
 307.091 
 
 7504.5 
 
 70* 
 
 219.911 
 
 3848. 5 
 
 84 . 
 
 263.894 
 
 5541.8 
 
 98 
 
 307.876 
 
 7543.0 
 
 / 
 
 220.697 
 
 3876.0 
 
 
 264.679 
 
 5574.8 
 
 H 
 
 308.661 
 
 7581:5 
 
 Yz 
 
 221.482 
 
 3903.6 
 
 y* 
 
 265.465 
 
 5607.9 
 
 
 309.447 
 
 7620.1 
 
 % 
 
 222.268 
 
 3931.4 
 
 % 
 
 266.260 
 
 5641.2 
 
 % 
 
 310-232 
 
 7658.9 
 
 71 
 
 223.053 
 
 3959.2 
 
 85 
 
 267.035 
 
 5674.5 
 
 99 
 
 311.018 
 
 7697.7 
 
 "/ 
 
 223.838 
 
 3987.1 
 
 i/ 
 
 267.821 
 
 5707.9 
 
 M 
 
 311.803 
 
 7736.6 
 
 Va 
 
 224.624 
 
 4015.2 
 
 Yz 
 
 268.606 
 
 5741.5 
 
 Yz 
 
 312.588 
 
 7775.6 
 
 % 
 
 225. 409 
 
 4043.3 
 
 % 
 
 269.392 
 
 5775.1 
 
 % 
 
 313.374 
 
 7814.8 
 
 72 
 
 226.195 
 
 4011.5 
 
 86 
 
 270.177 
 
 5808.8 
 
 100 
 
 314.159 
 
 7854 
 
 /i 
 
 226.980 
 
 4099.8 
 
 /4 
 
 270. 962 
 
 5842.6 
 
 
 
 
 y 2 
 
 227.765 
 
 4128.2 
 
 Yz 
 
 271.748 
 
 5876.5 
 
 
 
 
 3 
 
 228.551 
 
 4156.8 
 
 % 
 
 272.533 
 
 5910.6 
 
 
 
 
 ""S 
 
 229.336 
 
 4185.4 
 
 87 
 
 273.319 
 
 5944.7 
 
 
 
 
 Ji 
 
 230.122 
 
 4214.1 
 
 
 274.104 
 
 5978.9 
 
 
 
 
 i4 
 
 230.907 
 
 4242.9 
 
 Yz 
 
 274.889 
 
 6013.2 
 
 
 
 
 
 231.692 
 
 4271.8 
 
 
 275.675 
 
 r>047.fi 
 
 
 
 
MISCELLANEOUS TABLES. 179 
 
 TABLE OF PISTON SPEEDS. FEET PER MINUTE 
 
 Stroke in 
 Inches. 
 
 s 
 
 .00 co oo 
 
 ) O X*. to 
 
 1 00 -4 O 
 
 . *- O 00 Oi .>. OO tG O O 00 00 
 i oo O <> O<iOJ O -^ 00 O I C^ 
 
 
 58l 8 
 
 )<l OS V yi i*^ >U >U ; 
 ' t* O OS M 00 >U O < 
 
 > C O O O O O C i 
 
 > o o o o ^ 
 
 IS3SSI 
 
 
 4w Ci 
 
 ^^C^ 
 
 ;58l.i 
 
 li_i-ii _M 
 
 "to~to to - i-n 
 
 liil i 
 
 
 rf^. C5 OiiOOOO*i*OtC4X.O 
 
 PllfSillilSSjggStSSfeSg! 
 
 _o i 1 o_o ojo oa o o CT> oo o ? oo-o <i. w oo o oo -^ m i 
 
 "iC CO.'ltC K>"tO >-*" M t-i i-i' i^Ti- i-i " " ~ 
 
 ~co co"oo tototcrc>-'M> h^i-n-ii-i 
 
 ^88g8S: 
 
 
 
 !3 SS 
 
 )<JO I O 
 
 ^ O O O O ^C Oi O O O5 OC' O Ci 00 O O ' 
 
 o^Ooo^>o;ooo5>-'C5--iSo- : b< 
 
ADVERTISEMENTS. 
 
 *jot3C:<3 
 
 f | S, 5 K- 5 I mm 
 
 "1 C (D J 3 f" 1 *> 
 
 SJBpBBP^S p-n g 
 
 T CO IT" ~ PHHI 
 
 W3 O P^ > ^^ / O ^PV *r _^t 
 
 mifiB * s iiii a 
 
 05 O (t 2 S O & 1 ^B'-R* 1 
 
 09 p< i R) n i 
 
ADVERTISEMENTS. 
 
 GARDNER T. VOORHEES, S. B 
 
 Refrigerating 
 
 engineer 
 
 OPINIONS, ESTIMATES, PLANS, ETC., 
 
 FOR 
 
 Refrigerating^Ice Plants 
 
 INDICATOR CARDS 
 WORKED UP, ETC. 
 
 41 RICHMOND STREET 
 BOSTON 
 
ADVERTISEMENTS. 
 
 HOW DO 
 YOU KNOW 
 
 Whether your ENGINE is 
 working- ECONOMICALLY 
 and developing- FULL POW- 
 ER for FUEL consumed ? 
 NOTHING but an INDICA- 
 TOR will give you this knowl- 
 edge, and there is no INDICATOR su- 
 perior to the IMPROVED ROBERTSON 
 THOMPSON, and the price is about one- 
 third lower than any other. 
 
 works WET steam or BOILER foams, 
 a HINE ELIMINATOR will correct both 
 at trifling- cost. 
 
 IF YOUR ENGINE 
 
 WET steam or BOILER fc 
 E ELIMINATOR will correct 
 ing- cost. 
 
 JAS. L. ROBERTSON & SONS, 204 Fulton Street, NEW YORK 
 
 "BOYLE" 
 
 ice Making and Refrigerating Machinery 
 
 BUILT BY THE 
 
 Pennsylvania Iron Works Company 
 
 PHILADELPHIA 
 
 New York Office, 621 Broadway 
 
 A HANDSOMELY ILLUSTRATED CATALOGUE SENT ON APPLICATION. 
 
 Also Builders of the.... 
 
 Qas and Gasoline 
 Engines.... 
 
 For Stationary and Marine Service. 
 
ADVERTISEMENTS. 
 
 STflR BRflSS MFG. GO. 
 
 MANUFACTURERS OF 
 
 HIGHEST 
 GRADE 
 
 Ammonia Gages 
 
 FOR 
 
 Ice and 
 Refrigerating 
 
 Machines 
 
 ALSO 
 ORIGINAL 
 AND 
 
 EXCLUSIVE 
 MANUFACTURERS 
 OF 
 
 "Non -Corrosive'' 
 Pressure and 
 Vacuum Gages 
 
 OF ALL 
 DESCRIPTIONS 
 
 ALSO 
 
 Solid Nickel Seated Pop Satety Valves. 
 
 NOTE Our gages are used exclusively by the 
 Quincy Market Cold Storage Co.. Boston. 
 
 SPECIFY THEM ON NEW EQUIPMENT 
 
 108-114 East Dedham Street, 
 BOSTON, MASS. 
 
 THIRD EDITION 
 
 Compend of 
 
 Mechanical 
 
 Refrigeration 
 
 BY 
 
 PROF. J. E. SIEBEL. 
 
 DnirwJ Bound in Cloth, - $8.00 
 ' ' v - 1 in Morocco, 3.50 
 
 ON RECEIPT OF PRICE 
 
 H. S, RICH & CO., 
 
 Publishers 
 
 206 BROADWAY 177 LA SALLE ST. 
 
 NEW YORK CHICAGO 
 
ADVKRTISKMENTS. 
 
 TUB BJCHELDER "ST IIDICBTOR 
 
 AND IDEAL REDUCING WHEEL 
 
 COMPLETE, 
 
 COMPACT 
 
 AND 
 
 RELIABLE 
 
 JOHN s. BUSHNELL,SOLE MANUFACTURER 
 
 (SUCCESSOR TO THOMPSON &. BUSHNELL) 
 
 120 AND 122 LIBERTY ST., NEW YORK 
 
 Practical 
 Ice Making and 
 
 Refrigerating 
 
 A practical, common sense treatise 
 on the construction and operation 
 of Ice Making- and Refrigerating- 
 Machinery and Apparatus : : : : 
 
 El LJ G E IM E: T. S K I IVJ K l_ El . 
 
 "THE BOY" 
 
 BOUND ix CLOTH, ........ $1.50 
 
 j BOUND IN MOROCCO, ........ 2.00 
 
 SENT PREPAID TO ANY ADDRESS ON RECEIPT OF PRICE. 
 
 & CO., Rutoli 
 
 177 La s : il I., st., CHICAGO 
 206 Broadway, NEW YORK 
 

 39 (402s) 
 
ml *-^/^ 
 I OOUO 
 
 THE FRED W. WOLF Co. 
 
 Cable A 
 
 Manufacturers Export 
 
 and 
 Engineers and Architects A. B. c. Code Used. 
 
 MANUFACTUKKKS OK 
 
 THE LINDE ICE MAKING 
 
 in actual operation, and Refrigerating Machine 
 
 4 times as many as 
 any other ice machine. 
 
 For Durability, Simplicity and 
 It Has No Equal 
 
 Ammonia Fittings 
 
 Ice Factory Supplies 
 
 T^J-32 
 
 Ammonia Condensers, Ice Can Thawing Dumps, 
 
 Baudelot Coolers, Ice Tools, 
 
 Direct Expansion Piping, Pumps, 
 
 Brine Piping, Derricks, Etc. 
 
 General Offices, 139=143 Rees Street, Foot of Dayton 
 Factory, 302-330 Hawthorne Avenue 
 
 CHICAGO, U. S. A. 
 
 Catalogs Sent on Application. 
 
 : , ' ;" "'-', 
 
 \