MMMMMMI PRACTICAL STEAM AND HOT WATER HEATING i) VENTILATION LFRED G.KING Illilll Hi WSe. maunm JLIH& /9A5" dpt. Ento eertog PRACTICAL STEAM AND HOT WATER HEATING AND VENTILATION BY ALFRED G. KING PRACTICAL STEAM AND HOT WATER HEATING AND VENTILATION A MODERN PRACTICAL WORK ON STEAM AND HOT WATER HEATING AND VENTILATION, WITH DESCRIPTIONS AND DATA OF ALL MATERIALS AND APPLIANCES USED IN THE CONSTRUCTION OF SUCH APPARATUS; RULES, TABLES, ETC. BY ALFRED G. K^ING AUTHOR OF "PRACTICAL HEATING ILLUSTRATED," ETC. SECOND EDITION, EEVISED CONTAINING OVER THREE HUNDRED SPECIALLY MADE ILLUSTRATIONS SHOWING IN DETAIL ALL OF THE VARIOUS HEATING SYSTEMS, WITH PIPE, RADIATOR PNO BOILER CONNECTIONS NEW YORK THE NORMAN W. HENLEY PUBLISHING COMPANY 132 NASSAU STREET 1913 ttt, Engineering library COPYRIGHT, 1908, BY THE NOEMAN W. HENLEY PUBLISHING COMPANY COPYRIGHT, 1912, BY THE NORMAN W. HENLEY PUBLISHING COMPANY COMPOSITION, ELECTROTYPING AND PRESS- WORK BY TROW DIRECTORY, PRINTING AND BOOKBINDING COMPANY, NEW YORK, U. S. A. PREFACE FROM a more or less experimental stage to one of an exact science has been the progress of the art of artificial heating and ventilation during the period covering the past twenty-five or thirty years. In the early days of this industry there were but few competent fitters located outside of the larger cities. However, of later years the above conditions have changed, due in a great measure to the constant advancement and education of the steam fitting trade. To-day it is not an uncommon thing to find in a small city or town one or more steam fitters entirely competent to install almost any kind of a steam or hot-water heating appa- ratus. This education of the steam fitter has been accomplished largely by the frequent publication in the trade papers of much practical information, accompanied by drawings and data which could be readily understood by him. The publication of a number of books on the subject of Steam and Hot-Water Heating and Ventilation has also been of great assistance to the steam fitter in his mental advancement. How- ever, much of the matter contained in these books is too technical and of a nature too difficult to be clearly understood by a man of average education. In presenting this work the author wishes to give a brief history of the science of steam and hot-water heating and ventilation and the early methods of constructing work, and to describe and illus- trate the advancement and improvements over the earlier methods. By the illustrations, rules and explanations given, we shall aim to make plain to the steam fitter or apprentice the best methods of 8 PREFACE estimating and installing heating work by any one of the modern methods or systems now in use. To keep pace with the means and methods employed we must be continually studying and actively interesting ourselves in the improvements as they are brought out. The methods of a score of years ago have given place to other and improved methods and further experimenting and study by the wdde-awake American mechanics are bound to result in still further progress. To those authors and authorities from whose works we have quoted and to the manufacturers of heating appliances who have so kindly assisted us, we extend our thanks. Our effort is not to criticise but rather to comment upon the various heating and ventilating systems in vogue at the present time and to instruct the steam fitter in a practical way regarding their application and installation. We have also added such tables, rules and general informa- tion as will make this valuable as a reference book for the con- tracting steam fitter. A. G. KING. OCTOBER, 1912. CONTENTS CHAPTER I PAGE Introduction Modern methods of steam and hot-water heating and ventilation Evolution of steam and hot-water heating and ventilation The practice of heating and ventilation Steam and hot-water heating and ventilation A practical treatise Steam and hot-water heating and ventilation and practice 15 CHAPTER II Heat Nature of heat How measured How transmitted The heat unit (B. T. U.) Radiating power of bodies Absorption of heat .... 18 CHAPTER III Evolution of artificial heating apparatus Open fire-places Stoves Furnaces Average life and cost Healthfulness Early type of boilers Steam boilers, Hot-water heaters CHAPTER IV Boiler surfaces and settings Grate surface Water surface Boiler setting The safety valve The steam gauge The automatic damper regulator The water column and gauge glass The blow-off cock The firing tools and brushes The fusible plug 40 CHAPTER V The chimney flue Sizes of chimneys Elements of a good fliie Proper construc- tion of chimney flues Heights of chimneys Table of heights and areas . 56 9 10 CONTENTS CHAPTER VI PAGE Pipe and fittings Pipe Table of sizes Threading of pipe Bending of pipe Expansion of pipe Table of pipe expansion Wrought-iron or steel pipe Nipples Couplings Fittings Branch tees Flanges Table of flanges Measuring pipe and fittings 63 CHAPTER VII Valves, various kinds Air valves, various kinds 73 CHAPTER VIII Forms of radiating surfaces Radiators Pipe coils Coil building ... 81 CHAPTER IX Locating of radiating surfaces Direct radiators Indirect radiators Table of air ducts Direct-indirect radiators 91 CHAPTER X Estimating radiation Rules for estimating For steam For hot water Some dependable rules 97 CHAPTER XI Steam-heating apparatus The circuit system The divided-circuit system The one-pipe system Dry returns The overhead system The two-pipe system Advantages of steam heating Tables Sizes of mains . . . .103 CHAPTER XII Exhaust-steam heating Value of exhaust steam Necessary fixtures Heating capacity of exhaust steam 115 CHAPTER XHI Hot-water heating Two-pipe system Sizes of mains for two-pipe system The expansion tank Water connection Table of expansion-tank sizes The overhead system Expansion-tank connections for overhead system The circuit system Sizes of mains for circuit system Why water circulates . 120 CONTENTS 11 CHAPTER XIV PAGE Pressure systems of hot-water work Table of temperatures Expansion-tank connections for pressure work Evans and Almirall systems .... 141 CHAPTER XV Hot-water appliances The altitude gauge The hot-water thermometer Floor and ceiling plates Pressure appliances The Honeywell system The Phelps heat retainer 146 CHAPTER XVI Greenhouse heating Early method Modern greenhouse heating Estimating radiation for greenhouses Table of temperatures Methods of greenhouse piping 155 CHAPTER XVII Vacuum vapor and vacuum exhaust heating Explanation of a vacuum Im- proved methods of exhaust heating The Webster system The Paul system The Van Auken system Mercury seal systems The K.M.C. system The Trane system The Ryan system Vapor heating The Broomell system Vacuum vapor heating The Gorton system The vacuum-vapor system Dunham vacuo-vapor system The future of vacuum heating . 163 CHAPTER XVIII Miscellaneous heating The heating of swimming pools Heating water for domestic purposes Steam for cooking and manufacturing .... 189 CHAPTER XIX Radiator and pipe connections Steam radiator connections, hot-water radiator connections Improper use of tees Methods of pipe construction Artificial water-lines Cross-connecting boilers Pipe measurements for 45 and other angles .199 CHAPTER XX Ventilation Importance of ventilation Air necessary for ventilation Amount of air required Methods of ventilation . 211 12 CONTENTS CHAPTER XXI PAGE Mechanical ventilation and hot-blast heating Growth and improvement Methods employed Exhaust and plenum Heat losses and heating capacity required Quality of the air supplied An ideal system Fans for blowing and exhausting. Types of heaters Methods of driving fans Some details of construction Factory heating Relative cost of installation and opera- tion Apparatus for testing 224 CHAPTER XXII Steam appliances Steam traps Return traps Separators Oil separators Steam separators Feed-water heaters Steam pumps Boiler feed pumps Vacuum pumps Pump governors and regulators Back-pressure valves Pressure-reducing valves Injectors Inspirators Automatic water feeders . 262 CHAPTER XXIII District heating Early methods Modern methods Central station hot-water heating Scale of hot-water temperatures 288 CHAPTER XXIV Pipe and boiler covering Importance of covering pipes Saving effected by covering Materials used Underground covering 293 CHAPTER XXV Temperature regulation and heat control Automatic steam damper regulator, automatic temperature regulators The Powers thermostat, the Powers system The National regulator The D. & R. regulator The Howard regulator The Minneapolis regulator The Lawler thermostatic regulator The Johnson pneumatic system 299 CHAPTER XXVI Business methods Estimating Proposal and bid Specifications for steam heat- ing Specifications for hot-water heating Special features of contracts . 316 CONTENTS 13 CHAPTER XXVII PAGE Miscellaneous Care of heating apparatus Summer care Proper attention to boilers Removal of oil and dirt Summer tests to determine efficiency Care of tools Labor-saving suggestions Bronzing, painting, and decoration Guaranty Boiler explosions Prevention of boiler explosions Utilizing waste heat . . 329 CHAPTER XXVIH Rules, Tables, and Useful Information 347 PRACTICAL HEATING AND VENTILATION CHAPTER I Introduction IT is well in beginning the study and consideration of the science of heating and ventilation to look back to the start of what has grown to be one of our most important industries. We may properly term it Domestic Engineering, as on the work of the heating and ventilating engineer depends largely the health, and consequently the happiness, of the great body of civ- ilized people of the world. There is no doubt that the use of hot water for heating pur- poses antedates the use of steam. We have a more or less obscure record of the use of hot water in this respect by the Romans. In the beginning of the eighteenth century we have records of green- houses (at that time called " hothouses ") being successfully heated by hot water and later in the same century, about the year 1775, we find a Frenchman, Bonnemain, using hot water to heat a brooder on a chicken farir. This may be said to be the beginning of the practical application of hot water for heating purposes. Steam was probably first used for heating purposes in the early part of the nineteenth century, when efforts were made to heat a factory by steam at a high pressure. The development of steam heating from that date to the present time has been both rapid and constant, although the last decade has seen this industry ad- vanced to a state of perfection never dreamed of by the early heating engineers. From a loose and haphazard method of figur- ing and installing work of this character, it has reached a scientific stage, and as such is more or less understood by^ a large majority of those engaged in the business. 15 16 PRACTICAL HEATING AND VENTILATION Heating and Ventilation are kindred trades and sciences, each, in a measure, dependent on the other. The early effort to ventilate the British House of Commons, in 1723, was probably the real be- ginning of artificial ventilation. Dr. J. F. Desaguliers, a French boy, whose father removed to England when Desaguliers was but an infant, was, without doubt, the most distinguished student of physics and mechanics of that time. To him was intrusted the problem of ventilating the House of Commons. Previous to this date, however, other plans had been tried to provide a means of ventilation, but we believe the first scientific study and experiments were conducted by Dr. Desaguliers. Efforts were put forth during the early part of the nineteenth century to improve on this ventilating apparatus by the pro- viding of large fans or blowers, which were propelled by hand. The ventilation of other public buildings was then undertaken and the science had advanced to such a stage that in the year 1824 an English engineer, Tredgold by name, published a book entitled " Principles of Warming and Ventilating Public Buildings " a standard work still referred to at this date. While the history of the sciences of heating and ventilation and the endeavors of many engineers of eminence may be both interesting as well as instructive, we refer only to the beginning in order that our readers may realize, to the fullest extent, the evolution of the methods of heating by steam and hot water and ventilating by natural or mechanical means. To such men as Tredgold, Dr. Reid, Charles Hood, E. Peclet, Robert Briggs and others of earlier date, and Mills, Billings, Baldwin, Carpenter and other engineers of these latter times, are we indebted for the advancement and perfecting of the various methods of estimating and constructing the warming and ventilat- ing systems of to-day. The remainder of the credit is justly due to those who manu- facture and install the work and who have, by the use of modern machinery and up-to-date ideas, reduced the cost of steam and hot-water warming and ventilating apparatus to such an extent as to place it within the reach of those in moderate circumstances. Our public schools are better warmed and ventilated than ever INTRODUCTION 17 before, as are also the majority of our other public and semi-public buildings. Our architects now study and consider the subject of heating and ventilation and we firmly believe that the coming decade will witness far greater advancement in these sciences than we have known before. An estimate made in the year 1906 shows that but a little over one tenth of our homes and public buildings are provided with steam or hot-water heating apparatus. Such an estimate further reveals the fact that less than two per cent of our homes are pro- vided with even a partial ventilating apparatus. As a nation we seem to have been satisfied to roast one side of our body while the other side was chilled, or, when fresh air was absolutely needed in the room, to open the door or window, re- gardless of the outside temperature or the condition of the weather. These sudden changes, of course, produced colds and bodily ills of like nature, which, no doubt, in many cases, proved fatal. We knew of no uniformity in either the temperature of the house or the purity of the atmosphere in the several rooms. Becoming aware of our mistakes of the past, we now demand a uniform temperature within our homes; we are swiftly coming to the conclusion that we might better pay the coal dealer for the energy to produce heat, ventilation and comfort than to pay our physician for doctoring the ills resulting from our carelessness. It will be readily noted what a tremendous field there is for study and work along these lines, and to the journeyman steam fitter or contractor who fits himself thoroughly for this work, we see an abundant reward in store. CHAPTER II Heat HEAT is motion, or a form of energy. Scientists tell us that it is their belief that all matter is made up of small vibrating par- ticles called molecules. The faster these particles move or vibrate, the more heat is produced, and the more the matter or body is expanded. This expansion may be carried to such an extent as to transform the body into another state. For example, note the formation of gas from coal or oil, or the formation of steam from water. With a hammer we may pound upon a piece of iron until it becomes hot. The Indians started a fire by briskly rubbing to- gether two pieces of wood, the energy of motion producing the necessary heat to ignite the dry moss, or other material used for kindling. The nature of heat is peculiar and it is well that we become somewhat acquainted with these peculiarities. Heat cannot be measured as to quantity, but the intensity of heat may be measured by a thermometer, and this measure we call temperature, and for registering this temperature we use the Fah- renheit scale. For example, water freezes at 32 F. and boils at 212 F. (Fahrenheit was a German, who in 1721 made the first mercurial thermometer. ) Heat may be transferred from one body to another by three distinct methods, namely, Conduction, Convection and Radiation. Lay a piece of hot iron upon another piece of iron, or a different object, and a certain proportion of the heat from the heated iron is transferred to the under object. This method is by Conduction. Water which has been heated and transferred to a storage tank through pipes makes the tank hot. This is heating by Convection. We may place a chair too near a heated stove and burn or blister the paint or finish upon same. The chair has not been 18 HEAT 19 against the stove, neither has there been any direct connection between it and the heat producer, yet it has received the heat from the stove to such an intensity as to damage it. This damage was caused by radiation of heat, the heat being carried to the chair upon waves of air usually imperceptible to the eye. It is this latter method of heat transfer which is employed in the warming of buildings. The energy is developed at a boiler, or heater, placed usually in the basement of the building, the heat being transferred to the radiators, or radiating surfaces placed within or adjacent to the room to be heated and the heat again transferred to the room by radiation. While we cannot properly measure heat itself, we may measure it by the effect it produces, and this is accomplished by the so-called Heat Unit. The Heat Unit as adopted for engineering and scien- tific purposes is of three measures : viz., British, French and Ger- man. In this country it is the former that has come into general use. A British Thermal Heat Unit (B. T. U.) is the amount of heat required to raise the temperature of a pound of water one degree Fahrenheit, or one degree on the Fahrenheit scale of measuring. The British system of measuring heating work, or the effect pro- duced by the action of heat, is by what is known as foot pounds. Professor Allen's definition of this term foot pounds is as simple as we have come across. He says : " Ten units of work or ten foot pounds would be the amount of work done in raising ten pounds one foot high, or one pound ten feet high." Professor Allen thus calls our attention to the definite relationship between heat and work, which was probably first determined by Joule in 1838 while conducting a series of experiments. In measuring work the term horse power (H. P.) is fre- quently made use of. A horse power is 33,000 foot pounds per minute, or the amount of work required to raise 33,000 pounds one foot high per minute, and this is equivalent to 42.5 heat units per minute. As in this country the capacity of all engines and machinery, and all tubular and power boilers, is expressed by horse power, it is well to remember that a horse power represents the energy de- veloped by evaporating 2.655 pounds of water into steam, and which is sufficient to supply 100 square feet of radiation. Fur- 20 PRACTICAL HEATING AND VENTILATION thermore, a horse power represents the condensation from 100 square feet of direct cast-iron radiation, or approximately 90 square feet of pipe radiation or heating coils. The steam is condensed by loss of heat or cooling, and we must know in what manner certain elements act upon the heating surface to cool it, and again in what manner the heat is given off from the radiator or heated body. All building material is porous and there is a loss of heat through walls and window glass. Again, a ventilating register may be open in the room. There is a constant loss of heat through this aperture until such time as it is closed. Therefore, to de- termine upon the amount of heat necessary we must take into con- sideration all heat losses and this we shall discuss later on in this work. Heat is radiated in straight lines or in waves from a heated body. If certain objects are placed in the line of these waves they will absorb the heat and transmit it again to some cooler body. On the contrary, such substances as magnesia, asbestos, hair felt, and the like, will prevent the radiation of the heat beyond their influence. For example, note the plastic covering on boilers, or the asbestos and hair-felt coverings placed on steam and hot-water pipes. Air and other gases are almost transparent to heat and, in fact, in many cases assist in conveying it from the source of energy to the body to be warmed. The radiating power of bodies differs materially. Polished or enameled surfaces radiate less heat than rough or unfinished sur- faces. , Peclet gives the following table of the radiating power of bodies, the figures equaling heat units given off from a square foot of surface per hour for a difference of one degree Fahrenheit : TABLE NO. I RADIATING POWER OF BODIES Polished Copper 0327 Sheet Iron 0920 Glass 5940 Cast Iron (rusted) 6480 Stone, Wood or Brick 7358 Woolen Material 7522 Water... 1.0850 HEAT 21 A cast-iron radiator will radiate much less heat when enameled than when painted with bronze or a mineral paint. Specific heat is the amount of heat necessary to raise the tem- perature of a solid or liquid body a certain number of degrees, taking water as a unit or standard of comparison. Some bodies absorb heat more rapidly than others. According to Walter Jones, M.E., the heat necessary to raise one pound of water one degree will raise 32 Ibs. of Lead 31 Ibs. of Mercury 9 Ibs. of Iron 4l/ 2 Ibs. of Air or 52 Ibs. of Ice one degree. For the practical purposes of the steam fitter it is necessary only that he consider: 1. The energy necessary to produce a certain amount of heat, or number of heat units ; how produced, and how measured. #. How these heat units may be transferred, radiated or con- ducted from one body to another. 3. The effect of this heat upon the cooler body to which it is transferred, or the so-called cooling surfaces of a room or building. 4. The percentage of loss of energy by radiation, or other- wise, between the production of the heat and its delivery to the body to be warmed. In the discussion of radiation, ventilation, etc., we shall give other peculiarities and facts regarding the loss of heat, the causes leading to the same and rules for providing against the amount of heat loss under varying conditions. CHAPTER III Evolution of Artificial Heating Apparatus THE arrangement of some form or method of securing warmth within our homes or buildings is a matter to which our attention has grown in keeping with our advancement as a nation. History relates that among the ancient Romans it was custom- ary for the poorer class to build fires upon a stone or brick floor located at one side or end of a room, the smoke and soot passing out of the room through holes in the roof. The wealthier class used braziers in their living rooms, in which was burned carefully dried wood. The heating apparatus of our forefathers was the open fire- place, and it is related of the old New England type of fireplace that it was six or eight feet in length and so deep that the children had blocks on which they sat far within, where they could see the stars up the chimney. Large logs of wood were used for fuel. Later, after coal could be purchased, the fireplace was built very much smaller. In either case a very large proportion of the heat thus obtained escaped up the chimney, probably from seventy-five to ninety per cent being lost in this manner. As the country grew in population, cities and towns sprang up and fuel became scarcer. Larger buildings were erected and the number of rooms increased until, as a matter of economy, it became necessary to provide some other form of heating apparatus. To this end the old Franklin stove was designed, followed by later styles more improved, all in order to provide better combus- tion and save the lost heat. Again was " necessity the mother of invention," as, to save labor of carrying fuel and ashes for many fires, the idea of cen- tralizing the heating apparatus and of warming several rooms from one fire, led to the adoption of the inclosed stove. Tin or 22 EVOLUTION OF HEATING APPARATUS 23 sheet-iron pipes were used to convey the heated air to each separate room and from this arrangement developed the modern furnace. Experiments were next conducted with heated water and steam as means of conveying heat from a central point to various parts of a building, a form of heating which has been carried to such a state of perfection as to warrant the use of either system under almost any known condition, and the establishing of foundries and shops for the manufacture of heating apparatus. The develop- ment has been such that at the present time there are many millions of dollars invested in the business of manufacturing and installing apparatus for heating by steam and hot water. The relative efficiency of the several methods of heating may be given as follows : 1. Open Fireplaces. 2. Stoves. 3. Hot-Air Furnaces. 4. Steam. 5. Hot Water. In classifying them in this order, we consider not only efficiency, but healthfulness, durability, and cost of maintenance, i. e., cost for fuel. Were healthfulness alone considered, we should prefer the open fireplace to either stoves or furnaces. The waste of fuel in fireplaces and stoves, largely also in hot-air furnaces, is too well known to need many comments. Fireplaces radiate the heat from one side of the room only, and stoves warm but in spots. Furnaces fail to produce the right results when placed in build- ings not well protected from the wind ; and there is no uniformity in temperature where any one of the three above-mentioned sys- tems are used. Furnaces as ordinarily installed are not much more satisfactory than stoves, and nine tenths of them are too small. They are used in preference to a steam or hot-water apparatus because of the apparent saving in cost. We say apparent saving in cost, as after all things are weighed, there is no saving in using a furnace in preference to steam or hot water, and it is well that the steam fitter or heating contractor has this fact clearly in mind. There- 24 PRACTICAL HEATING AND VENTILATION fore, we shall discuss this feature of furnace heating very freely and shall consider the matter, endeavoring to show a comparison between the furnace and steam or hot-water heat. First: As to cost and average life of the apparatus. Second: As to comfort and healthfulness. Average Life and Cost Where a furnace too small is installed, it is necessary, in ex- treme cold weather, to raise the heating surfaces to an exceedingly high temperature, often a red heat, in order to secure comfort. As a result, the expansion and contraction loosens the joints of the furnace and allows the sulphurous and carbonic-oxide gases and other poisonous products of combustion to escape through the hot- air pipes into the rooms above. This is true of both wrought- iron and cast-iron furnaces. Again, heating the furnace to this extremely high temperature shortens the life of the apparatus, with the result that ten per cent of the first cost is needed for repairs during the first five years, while, as a rule, the next five years find the furnace entirely worn out. A steam-heating apparatus has an average life of probably twenty-five years, the first ten years of this period without any repairs except of a trivial nature, such as the repacking of valves, etc. A hot-water-heating apparatus will last an even greater length of time, without the expense of repairs, the system being practi- cally indestructible. Thus it will be readily seen that while the cost of a furnace, as usually installed, is but one half that of a steam-heating apparatus, or probably two fifths that of a hot- water-heating apparatus, it is, as an investment, not counting healthfulness or the excess amount of fuel consumed, by far the more costly of the three systems. In pondering the question of cost, we have not taken into con- sideration the long list of fires and damaged buildings resulting from the " defective flue," nor the damage to house furnishings, due to dust and dirt from the furnace. The housewife, more than anyone else, knows of the constant dusting and cleaning and the frequency with which it is necessary to renew carpets and draperies. EVOLUTION OF HEATING APPARATUS 25 Healthfulness of Furnace Heating GO" cT o" r-T o o o o o o o GC GO GO *O *O *O *O i>* O CO CO CO CO *O CD -^ CO flQ 00 ^ *4i ^> Q O CD 9 OP - o ecfri 1-S.2 !! >4*0 Cu. Ft. in 1 Lineal Ft. of Pipe. Weight of Water in 1 Ft. of Pipe. Pounds. ! 11 - 3 o -^< cr a iS ^ Length of Pipe Per Sq. Ft. Outside. Surface. H .068 .24 27 2513. .024 0.0583 9.44 .088 .42 18 1383.3 .044 0.1041 7.075 % .091 .56 18 751.5 .082 0.1917 5.657 % .109 .84 14 472.4 .132 0.3048 4.547 H .113 1.12 14 270.00 .25 0.5333 3.637 .134 1.67 HH 160.90 .006 .37 0.8627 2.903 1M .140 2.24 ii}% 96.25 .010 .647 1.496 2.301 iK .145 2.68 11^ 70.66 .014 .881 2.038 2.010 2 .154 3.61 HH 42.91 .023 1.45 3.356 1.608 WA .204 5.74 8 30.10 .032 2.07 4.784 1.328 3 .217 7.54 8 19.50 .051 3.20 7.388 1.091 3^ .226 9.00 8 14.57 .069 4.28 9.887 0.955 4 .237 10.66 8 11.31 .088 5.50 12 . 730 0.849 4J-2 .246 12.49 8 9.02 .111 6.92 15.961 0.764 5 " .259 14.50 8 7.20 .138 8.63 19.990 0.687 6 .280 18.76 8 4.98 .197 12.25 28.889 0.577 7 .301 23.27 8 3.72 .270 16.87 38.738 0.501 8 .322 28.18 8 2.88 .340 21.61 50.039 0.443 9 .344 33.70 8 2.29 .440 27.25 62 . 733 0.397 10 .366 40.00 8 1.82 .550 34.50 ^78.838 0.355 64 PRACTICAL HEATING AND VENTILATION The pipe used for steam, water and gas is graded in size from %" upward to the larger sizes. The internal diameter forms the basis of the pipe size as given. Pipe at present is manufac- tured in three thicknesses or weights, known commercially as " Standard," " Extra Strong " and " Double Extra Strong," the " Standard " weight being used on all steam and hot-water heat- ing work, and all reference to pipe in this book will apply to the standard weight unless stated otherwise. Among the tables published in the last chapter of this work will be found tables of sizes, weights, etc., of " Extra Strong " and " Double Extra Strong " pipe. Pipe up to and including 1%" in size is what is known as " butt welded," 1%" and larger, being " lap welded " and is manu- factured in lengths varying from 16 to 20 feet. Threading of Pipe All pipe is now threaded uniformly, the Briggs' standard of pipe-thread sizes being used by all manufacturers. The taper is an inclination of 1 in 32 to the axis, or %" to 1 foot. Bending of Pipe Some years ago it was a common occurrence to bend pipe, where offsets were needed, or change of direction required. The piece of pipe to be bent was filled with sand and both ends capped, the sand acting as an aid in preserving the form of the pipe, without flattening. It was then heated to a cherry-red color and bent to the desired form. In these later years but very little pipe is bent, the offsets or changes of direction being made with the use of cast- iron or malleable-iron fittings. The smaller sizes of pipe, such as are used for water or gas service, are frequently bent by the plumber without heating and without the use of sand. When it becomes necessary to do any considerable amount of work of this character, it is better to use bending blocks or bending forms. Expansion of Pipe In heating work the expansion of pipe, when heated, must al- ways be taken into consideration and opportunity given the pipe PIPE AND FITTINGS 65 to stretch without breaking fittings or straining joints. To this end all mains should be hung or supported by expansion hangers as shown by Fig. 45. Pipe connections, particularly on steam work, should be made by using elbows to form a swing or expan- sion joint. We shall speak of this more fully in discussing methods of steam piping. Whenever pipe is run through boxing, tile or other form of conduit, a roller support (see Fig. 46) should be used. FIG. 46. Roller support for piping. FIG. 45. Expansion pipe hangers. Pipe heated from 30 degrees to 212 degrees will expand about 1%" in 100 feet of length. The following table gives the expansion of 100 lineal feet of pipe heated to various degrees of temperature. TABLE VII EXPANSION OF WROUGHT-!RON PIPE Temperature of the Air When Pipe Is Fitted. Length of Pipe When Fitted. Length of Pipe When Heated to 215 265 297 338 Ft. Ft. In. Ft. In. Ft. In. Ft. In. Zero 100 100 1.72 100 2.12 100 2.31 100 2.70 32 100 100 1.47 100 1.78 100 2.12 100 2.45 ' 64 100 100 1.21 100 1.61 100 1.87 100 2.19 The number of degrees pipe is heated, corresponding approx- imately to steam pressure, as follows : 215= 1 Ib. pressure. 265 = 25 Ibs. pressure. 297 = 50 Ibs. pressure. , 338 = 100 Ibs. pressure. 66 PRACTICAL HEATING AND VENTILATION Wrought-iron or Steel Pipe Up to the year 1885, approximately, all pipe was made of wrought iron. At about this time the manufacture of welded steel pipe on a commercial basis was started. The difficulties experi- enced before in its manufacture, principally in welding, had been overcome by improvement, so that it could now be readily welded. The first of the steel pipe seemed hard and brittle and the steam fitter had considerable trouble in threading it. However, as now manufactured it is soft and tough in fiber and a die, if blunt, will tear the thread. Consequently it is necessary that the die be sharp in threading steel pipe. In appearance, iron pipe is rough and has a heavy scale, while steel pipe has a lighter scale, underneath which the surface is smooth. The grain of steel pipe is fine, while that of wrought-iron pipe is coarse. The author of this work is located near the center of the iron and steel industry and has endeavored to ascertain the difference in value between steel and wrought-iron pipe and our investigation may be summed up as follows : Steel pipe costs less to manufacture than wrought-iron pipe; it is, therefore, cheaper. With improved dies, threads may be cut on steel pipe as good, but not as quickly, as on wrought- iron pipe. When steel pipe is new it has a higher tensile strength than wrought iron. We are told that after a few years' use the reverse is the case. There seems to be no doubt but that wrought-iron pipe will last much longer than pipe made of steel, as it is less liable to cor- rode, the difference in longevity, under certain conditions, more than making up for the increased cost. To Ascertain Whether Pipe Is Made of Iron or Steel The following test is given us by an officer of an iron company : " Cut off a short piece of pipe file the end smooth to oblit- erate the marks of the cutting tool. Suspend the piece of pipe in a solution of nine parts of water, three parts of sulphuric acid and one part muriatic acid. Place the water in a porcelain or glass dish, adding the sulphuric and then the muriatic acid. Suspend the pipe in such a manner that the end will not touch the bottom PIPE AND FITTINGS 67 of the dish. After an immersion of about two hours, remove the piece of pipe and wash off the acid. If the pipe is steel, the end will present a bright, solid, unbroken surface; if made of iron, FIG. 47. Wrought-iron and steel pipe. it will show faint ridges or rings, displaying the different layers of iron and streaks of cinder," as shown by Fig. 47. Nipples Short pieces of standard pipe threaded at both ends are called " nipples " and are known commercially as " close," " short," or " long." A close nipple is one so short that in threading the ends, the threads join at the center of the nipple, and by the use of which two fittings or valves may be joined together close to each other. From this fact the nipple is called " close." The short nipple is one showing a small amount of bare pipe between the threads, the length varying from 1%" for % 7/ to i/o" nipples to 5" for nipples made from 1" to 12" pipe. SHOULDER NIPPLE CLOSE NIPPLE FIG. 48. Nipples. Long nipples run from 2" to G 1 /^" in length, according to the size of pipe. Fig. 48 shows the two kinds of .nipples and the following table gives lists of lengths and sizes. 68 PRACTICAL HEATING AND VENTILATION TABLE VIII WROUGHT-!RON NIPPLES Close. Short. Length in Inches. Long. Sizes. * 43^ 8 5 6 7 8 9 ]() Couplings Pipe is joined together by what is known as a coupling a sleeve of wrought iron tapped out or threaded right hand on the inside. Pipe mills furnish one coupling with each full length of pipe. They may also be obtained tapped right and left hand, if desired, although it is customary when using a right and left coupling to use one made of malleable iron. Reducing couplings WROUGHT IRON COUPLING R d L. MALLEABLE. COUPLING FIG. 49. Couplings. are also made of malleable iron, reducing from one pipe size to another of smaller size. Fig. 49 shows the wrought-iron right- hand coupling and the malleable right and left hand coupling. PIPE AND FITTINGS 69 Fittings The fittings used in connection with steam, gas or water pipe are of two general kinds, viz. : those made of cast iron and those made of malleable iron. By fittings we mean elbows, tees, crosses, flanges, bushings, caps, plugs, etc. For heating work the cast-iron fitting is used ; for gas piping, the malleable-iron fitting, and for domestic water supply, the gal- vanized malleable-iron fitting. We shall illustrate and describe only the cast-iron fitting. Cast-iron fittings are of two kinds, viz. : those having a flat bead, and those having a round bead, Fig. 50. " Straight " fit- ELBOW, ROUND BEAD ELBOW, FLAT BEAD FIG. 50. Beaded fittings. tings are those having all openings tapped for the same size of pipe. " Reducing " fittings are those tapped for different sizes of pipes. Fig. 51 shows a group of flat beaded fittings. The terms " male " and " female " fittings are sometimes used. By " male " fitting we mean one with the threads on the outside ; by " female " fitting we mean one with the threads on the inside. When reading or describing a tee fitting, the run is named first, the side opening last. If the run is tapped reducing, the larger tapping is read first. Thus a tee whose tappings are 3" X 2" X I 1 /;/' is read: three by two by one and one half inch. The top and side outlets of a cross are all of the same size, while the inlet may be the same size or larger. Thus a 2 X 1 X 1" cross would indicate that the bottom or inlet was 2" and the top and side outlets 1" in size. Branch Tees A fitting used largely on coil work is known as a Branch Tee, frequently (but erroneously) called a Branch Header. Shown by Fig. 52. All branch tees are tapped right hand in the run and 70 PRACTICAL HEATING AND VENTILATION in the branches, excepting when used in making box coils, when the branches are tapped left hand and the back opening right hand. R.i L. ELBOW 45 ELBOW FLANGED UNION REDUCING TEE ECCENTRIC TEE ECCENTRIC TEE RETURN BEND, WIDE PATTERN BACK OUTLET FIG. 51. Types of cast-iron fittings. Cast-Iron Flanges Cast-iron flanges are now made according to two uniform stand- ards. A joint committee of the Master Steam Fitters Association PIPE AND FITTINGS 71 and the American Society of Heating Engineers recommended a standard for a working pressure up to 125 pounds. This stand- ard has been adopted by all manufacturers, who also have a stand- INLET OPEN NO.3. FOR BOX COILS FIG. 52. Branch tees. ard of their own for pressures up to 250 pounds. The following gives all measurements for flanges, as used on heating work. TABLE IX SCHEDULE OF STANDARD FLANGES Size of Flange Pipe Size X Diam. 2 X 6 ty\/ v/ ri s"x ns> A x 8^ 4X9 5 X10 6 Xll 7 8 9 X15 10 X16 12 X19 14 X21 15 X22i^ 16 X23H 18 X25 20 Diameter of Bolt Circle. 6 7 7M 8 1 ! 18% 20 25 Num- ber of Bolts. 4 4 4 4 4 8 8 8 8 8 12 12 12 12 16 16 16 20 Size of Bolts, Pressure Under 80 Lbs. Size of Bolts, Pressure 80 Lbs. and Over. MX3 1 X4M Flange Thick- ness at Hub for Iron Pipe. Flange Thick- ness at Edge Width of Flange Face. 2 2M 3M Do not drill bolt holes on center line but symmetrically each side. 72 PRACTICAL HEATING AND VENTILATION Measuring Pipe and Fittings The proper method of measuring pipe and fittings is by " end- to-center " measure, or " center to center," the former being used in measuring a piece or length of pipe with a fitting on one end ; for example, with an elbow on the end of the pipe, measure from end of pipe to center of the elbow, or in case of a tee, measure from end of pipe to center of the side outlet of the tee. FIG. 53. Measuring pipe and fittings. In measuring center to center measurements, Fig. 53 shows the method employed. The illustration shows two elbows, a valve, a union and a tee, with dotted lines indicating method of measure- ment. When ordering pipe " cut to sketch " this manner of in- dicating measurements, no matter how crude the drawing, will guard against possible errors. CHAPTER VII Valves THE method employed in blocking or stopping the flow of steam or hot water in the piping or in the supply to the radiating surfaces of a steam or water warming apparatus is the placing of a cock or valve at some convenient point or points on the system, which may be opened or closed at will. The early types of cocks and valves, as used in connection with a heating apparatus, were very crude when compared with those used at the present time, and there is probably no part of the heat- ing apparatus which has received closer attention in the way of improvement in manufacture, utility and appearance, than the steam, water and air valves. The valves used in shutting off or supplying steam or water to the radiators are customarily called Radiator Valves. These are of several kinds, and, as a matter of convenience in connecting piping to a radiator, are usually provided with a union connection. As a rule, radiator valves are nickel plated all over, the body of the valve being left rough, the other portion being finished or polished. Fig. 54 shows the regular form of steam radiator valve with union, and has a ground seat and composition disk, the Jenkins Disk being the standard. Fig. 55 shows the regular form of the hot-water radiator valve. This is known as a quick-opening valve from the fact that it is made in such a manner that a quarter turn of the wheel will open or close the valve. A sleeve, with opening in the side, is attached to the stem and fitted closely inside the body of the valve. To operate the valve the opening in the sleeve is turned in the direction of the discharge opening of the valve ; to close the valve the opening in the sleeve is turned back from the discharge opening of the valve. In the early days of steam and hot-water heating, the valves used on. hot-water radia- 73 74 PRACTICAL HEATING AND VENTILATION tors were of practically the same design as those used on steam radiators. A change in the construction of the hot-water radiator valve was found necessary, as with the old type the water within the radiator ceased circulating when the valve was closed. This FIG. 54. Steam radi- FIG. 55. Hot-water radi- ator valve with union, ator valve with union. FIG. 56. Union elbow. complete stoppage frequently resulted in a freezing of the water in the radiating surface. To overcome this difficulty the sleeve of a hot-water radiator valve is now made with a small opening through it, so that, though the valve be closed tight, there is still a slight circulation within the radiator, and this effectually pre- vents freezing of the water. FIG. 57. Globe valve. FIG. 58. Angle valve. FIG. 59. Gate valve. Hot-water radiator valves of other patterns are manufactured and quite extensively used. As a matter of appearance and also of convenience in con- necting the return end of a hot-water radiator with the piping, VALVES 75 a nickel-plated brass elbow, with union connection, is used. This is commonly called a Union Elbow and is illustrated by Fig. 56. The principal valves used on piping are the Globe Valve, Fig. 57, the Angle Valve, Fig. 58, and the Gate Valve, Fig. 59, and there are many varieties of each. Some globe valves are made with a solid metal disk and seat ; others have a seat made of soft metal, w r hile some are provided with a composition disk of the Jenkins type, or similar. The diaphragm of a globe valve forms an obstruction in the valve, as will be noticed by referring to Fig. 60, which illustrates the in- terior of the valve. Consequently it is well to use this valve only on a vertical pipe, unless so set that the stem of the valve is hori- zontal. The angle valve is used on the piping in place of an elbow c :> c FIG. 60. Interior of globe valve. FIG. 61. Interior of gate valve. when change of direction is desired and it is found convenient to place the valve at this point. The gate valve (known also as the straightway valve) has superseded the globe and angle types of valves on nearly all work, as it has so many important advantages in comparison. It should always be made use of on hot-water piping, owing to the fact that, when open, there is nothing to prevent the free flow of water through the valve. See illustration, Fig. 61. Extra large globe and gate valves are frequently provided with a yoke or saddle, as shown by Figs. 62 and 63. We have still another form of valve, known as the Cross Valve, which, in construction, is quite similar to the angle valve, with the exception, however, that it has two discharge openings instead 76 PRACTICAL HEATING AND VENTILATION of a single one. The cross valve is a convenient one to use when it is desired to discharge in opposite directions. All of the above valves, shown in Fig. 57 to Fig. 63, inclusive, may be had in the larger sizes with flanges for bolting to com- panion flanges on the piping. FIG. 62. Globe valve with yoke. FIG. 63. Gate valve with yoke. When it is desired that the flow through a pipe should be in one direction only, the result is secured by the use of a form of valve, known as a Check Valve. It takes its name from the fact that it checks the reverse flow of steam or water in the pipe. These valves are of three varieties, the horizontal check, the vertical check and the angle check. The common type of check valve is what is known as the Swinging Check Valve, and is illustrated by Fig. FIG. 64. Swing check valve. FIG. 65. Interior of swing check valve. 64 and Fig. 65, the views showing the exterior and interior of the valve. There are other types of valves manufactured for special pur- poses, but those as above described and illustrated are those gen- erally used by the heating contractor. VALVES Air Valves 7? Doubtless no portion of a heating apparatus has received more attention or has been more experimented with and improved than has the air valve. In all heating apparatus it is necessary to pro- vide a means of escape for the air in the system, piping or radia- tors, and this is accomplished by the use of an air valve. The simplest form of an air valve is the compression valve. Fig. 66 FIG. 66. Wood wheel compression air valve. shows the common type of a wood-wheel compression air valve. Fig. 67 shows the type of compression air valve as used on a hot- water system ; this air valve is operated with a key. While we wish our readers to become familiar with the various types of air valves, it would be next to impossible to illustrate or describe all of them in a book of this character, as there is such a multiplicity of styles. In fact, nearly all manufacturers of radia- tor valves also make several patterns or designs of air valves. FIG. 67. Lock and shield compression air valve. Air valves are of two general kinds : positive and automatic. The positive type is of the compression variety, which we have already described and illustrated. Automatic air valves are all made on the same general prin- ciple, although various different metals or substances are employed in their manufacture. Most of the automatic air valves close by 78 PRACTICAL HEATING AND VENTILATION the expansion of and open by the contraction of the metal or sub- stance employed in the interior of the valve. The early types of automatic air valves are the Breckenridge, shown by Fig. 68 and Fig. 69, the Baker, shown by Fig. 70 and Fig. 71. In this type FIG. 68. Breck- enridge auto- matic air valve. No. 1 No. 2 No. 3 FIG. 70. Baker automatic air valve. FIG. 72. Interior of Victor automatic air valve. FIG. 69. Breck- enridge auto- matic air valve with drip. FIG. 73. Victor automatic air valve with wood wheel. FIG. 71. Inte- rior of Baker automatic air valve. of valve the strip of brass or tube used in the interior of the valve, when expanded by contact with the steam, will seat or close the valve, which will again open when the steam pressure is removed. VALVES 79 As automatic valves are now manufactured, the expansion post or tube is made of carbon or a composite material, which will ex- pand more quickly than metal, as shown by Fig. 72 and Fig. 73. Others are made with a combination of the expansion post and a float, which temporarily closes the valve should there be any water forced through the air-valve opening of the radiator. Fig. 74 shows an air valve of this type. Still another variety is that shown by Fig. 75. The float of this valve is sealed and contains a liquid extremely sensitive to FIG. 74. Automatic air valve with expansion post and float. FIG. 75. Russell automatic air valve. heat, which vaporizes at a temperature of 151 Fahr., expanding the ends of the float, which are corrugated, closing the valve. Some makes of air valves are provided with a vacuum attach- ment, which, working in connection with the float and expansion post, allows the air to escape under pressure from the steam, clos- ing against the steam when all air is expelled. When the steam pressure is removed, or the system is cooled, the attachment ef- fectually closes the air port preventing the return again of air through the valve. Thus the system is placed under a partial vacuum. 80 PRACTICAL HEATING AND VENTILATION One of the greatest of the troubles that the steam fitter has to contend with is air in the system. The radiators or radiating surfaces becoming air bound, the steam cannot enter, nor the hot water circulate. It is of importance then that the steam fitter should use a type of air valve which will effectually do the work required. CHAPTER VIII Forms of Radiating Surfaces ONE of the most interesting parts of the study of the science of steam and hot-water heating is to be found in following up the improvements in the beauty and utility of the radiating surfaces emploj'ed in the distribution of heat. Perhaps no part of a heat- ing apparatus shows so well the effort of " Yankee " ingenuity FIG. 77. The Whittier radiator. FIG. 76. The Verona radiator. as the various styles of heating surfaces we to-day call radiators, for the radiator is of American origin. From the old pipe box coil, or the " pan " radiator made of sheet iron, to the American Radiator Company's. " Verona," as shown by Fig. 76, or, in fact, almost any one of the present orna- 81 82 PRACTICAL HEATING AND VENTILATION mental cast-iron radiators, is an achievement of which any person connected with the heating industry may be justly proud. FIG. 78. The Bundy loop radiator. FIG. 79. The Reed radiator. It is probable that the first direct radiator to be manufactured and sold in any quantity was the original " Bundy " radiator, FORMS OF RADIATING SURFACES 83 made with a cast-iron base into which were screwed short lengths of one-inch pipe capped at the top and covered with a cast-iron FIG. 80. The Union radiator. FIG. 81. The Pyro radiator. fretwork top. This was followed by other makes of pipe-tube radiators of similar design. The first of the cast-iron direct radiators were the " Whittier," FIG. 82. The Elite radiator. Fig. 77, and the " Bundy " loop radiator, shown by Fig. 78. These radiators were placed on the market about the year 1873 or 1874, the former by the H. B. Smith Co. and the latter by the 84 PRACTICAL HEATING AND VENTILATION A. A. Griffing Iron Co. Improvements in design and manufac- ture followed almost immediately, the H. B. Smith Co. bringing out the " Reed " radiator, Fig. 79, and still later the " Union," shown by Fig. 80. The A. A. Griffing Iron Co. followed the "Bundy" with the " Pyro," Fig. 81 (1876), and the "Elite," Fig. 82 (1877). The Exeter Machine Co., of Exeter, N. H., were early in the field with the " Exeter," a cast-iron radiator of double- tube construction. FIG. 83. The Gold Pin indirect radiator. Of the cast-iron indirect radiators the " Gold " pin radiator, Fig. 83, was the first, the original being manufactured as early as 1862, and is no doubt the oldest of the cast-iron radiators in any form used for heating. The illustration shows the improved style which, however, is quite similar to the original. The " Bundy Climax," Fig. 84, is another type of the early indirect radiators. FIG. 84. The Bundy Climax indirect radiator. Radiators may now be obtained in numerous heights and widths to fill any desired space and in a multitude of designs of orna- mentation, which when properly decorated become a thing of beauty as compared with the ugly looking box coil. Illustrative of this we show a low-down window radiator, Fig. 85, of such a height that a seat may be built over it, thus making not only a warm and comfortable window seat, but adding also largely to the beauty of the room. FORMS OF RADIATING SURFACES 85 Pipe coils in residence heating have been almost entirely su- perseded by what is known as the Wall Radiator, Fig. 86. This FIG. 85. Window radiator. type of radiator is largely used in narrow halls, bath rooms, or in fact, any place where there is an abundance of wall space and FIG. 86. Wall radiator. but little floor space, and while not so effective as a pipe coil, is much more effective than the regular type of radiator. 86 PRACTICAL HEATING AND VENTILATION Cast-iron radiators, direct and indirect, and direct-indirect, are now manufactured by many concerns, the largest of which is the American Radiator Company, originally formed by the merging of the Pierce Company, of Buffalo, and the Detroit and Perfection Radiator Companies, of Detroit. The extremely large output of this concern, together with the other manufacturers of radiators, bears witness to the great popularity of steam and hot-water heat- ing in this country. Pipe Coils Pipe coils are still used largely on factory or other work where their appearance is not objectionable. There are several styles of pipe coils as generally used. Fig. 87 illustrates the Miter Coil RETURN BRANCH TEE- MITRE COIL FIG. 87. Mitre pipe coil. made with branch tees and right and left elbows. The position of the air valve, as shown at A, is for hot water. If for steam, the coil should be vented at end marked B and the air valve should be placed on the branch tee just above the lowest pipe of the coil. In building all coils used for steam, expansion must be provided for, and the angles in this style of coil formed by the right and left elbows provide for the expansion. It should always be used on walls at the position shown in the illustration, with the miter end up, and it may also be used as a ceiling coil. Fig. 88 shows the Corner Coil. This coil as shown and vented is for hot water, but may also be used for steam. The Return Bend Coil, Fig. 89, is not so good for steam FORMS OF RADIATING SURFACES 87 Co FIG. 88. Corner pipe coil Return Bend Cc Return FIG. 89. Return bend pipe coil. ETURN RETURN BRANCH TEE COIL FIG. 90. Return branch tee pipe coil. 88 PRACTICAL HEATING AND VENTILATION as either of those already mentioned, as the steam must travel through the entire coil in a single pipe. When used for steam it should be vented at B ; when used for hot water it should be vented at A. Fig. 90 illustrates the Return Branch Tee Coil. Where the length of wall space is limited, this is a very compact type of coil Standing Wall Coil FIG. 91. Upright coil pipe. to use. It is made with one set of right hand elbows, the other set being right and left hand elbows. When used for hot water, vent as shown at A; when used for steam, vent at end marked B, but place vent lower down on the coil, as recommended for coil shown by Fig. 87. FORMS OF RADIATING SURFACES 89 A style of coil used for hot water is shown by Fig. 91. Do not use a coil of this character for steam, as suitable provision is not made for expansion and trouble would ensue. To those who have had no very great experience in building coils it may not be amiss to say a few words regarding coil building. There are many methods of procedure, any one of which when the details are properly worked out will result in a neat and well- proportioned coil. We will take the miter coil for illustration, and our method is as follows : Determine the center to center measurements of the openings of the branch tees to be used and with an ordinary chalked H A~ FIG. 92. Diagram for coil making. line snap as many chalk lines upon the shop floor as there are openings in the branch tees to be used, making the distance be- tween the lines the center to center measurement of the openings in the branch tees. Calling these the horizontal lines, make at one end the same number of vertical lines the same distance apart. Determine the length and height of coil according to the space to be used, and then lay the branch tees and R. and L. elbows on the marks as shown by Fig. 92. It is well to have the left hand thread of the elbow looking toward the short or expansion end of the coil. Accurate measurements for the pipes may now be taken. The line A is the longest pipe of the coil. The line B is the longest of the upright or expansion pipes. To make a symmetrical and 90 PRACTICAL HEATING AND VENTILATION neat appearing coil the shortest upright pipe C should be in length but one third that of D, the shortest horizontal pipe. Cut right hand threads on each end of the long pipes and a right hand thread on one end of the short pipes and a left hand thread on the other end. Make the right hand side of the elbows on one end of the long pipes and make the other end of the pipe into one of the branch tees, with the elbows in proper position to receive the short end of the coil. FIG. 93. Coil partially completed. This portion of the coil now looks as shown by Fig. 93. Next Legin with the pipe marked C on Fig. 92 and make this up in the usual manner of making right and left hand connec- tions, following with the next shortest pipe and so on until coil is completed. While yet on the shop floor, see that the alignment of the pipes is perfect. If not, make it so, when the coil is ready to hang in position. EXPANSION PLATE RING PLATE COIL STANDS FIG. 94. Hook plates and coil stands. The same general method of laying out measurements is used in making all styles of coils. Wall coils are held in place by hook plates fastened singly or in groups, as shown by Fig. 94. Ceil- ing coils are hung or suspended by different forms of hangers so arranged as to give the proper pitch or drip to the coil and to allow of expansion and contraction. CHAPTER IX Locating Radiating Surfaces THE proper location of the radiator, whether direct, indirect, or direct-indirect, has much to do with the success of a heating plant. Direct radiators should be located on outside walls or under the windows of the most exposed parts of a building. Indirect radia- 15^ FIG. 95. Xiocating radiators and registers. tors, or more properly speaking, the register openings from in- direct radiators, should be located on the warmer or less exposed side of the room. With direct-indirect radiators it is well, if pos- sible, to place them under windows. To illustrate this we show 91 92 PRACTICAL HEATING AND VENTILATION by Fig. 95 a room with two walls exposed. The dotted line divid- ing the room cornerwise shows the warm and cold or exposed parts of the room. If heated by a direct radiator, it should be located in either of the positions shown, and if heated by indirect radiation the register should be located in the floor or wall at or near either position shown on the illustration. When called upon to place and box an indirect radiator the steam fitter frequently becomes confused. As an aid to the proper hanging and boxing of indirects we shall illustrate and describe the usual methods followed. Fig. 96 shows a method of installing an indirect where the hot- air flue and register are placed in the wall. Figs. 97 and 98 show FRESH AIR X\ FIG. 96. Indirect radiator register in wall. two methods of installing indirect radiators when floor registers are used. The casing or boxing should fit snugly against the radiator sections in order that the air will pass through the radiator and not around it, and the cold-air supply or duct should always be provided with a damper. It is well to take the hot-air duct from the boxing at the end opposite to that where the cold air enters in order that the air will travel as great a distance through the radiator sections as possible. A number of sections of indirect radiation when nippled or bolted together are usually referred to as a " stack " of indirect LOCATING RADIATING SURFACES 93 radiation, or as an " indirect stack." The space between the top of a stack and the casing should be from eight to ten inches and the space between the bottom of the stack and the lower side of the casing should be six or eight inches. FIG. 97. Indirect radiator register in floor. The hot-air supply or area of the hot-air duct should be, for hot water, 2 sq. in. of area, or for steam 1% sq. in. of area for each sq. ft. of radiation in the stack. As a general rule, the cold- V \ I / V Ret FIG. 98. Indirect radiator register in floor. 94 PRACTICAL HEATING AND VENTILATION air supply or area of the cold-air duct should be from two thirds (66f^) to three fourths (75^) of the area of the hot-air flue. Cir- cumstances vary these figures somewhat, but the above represents a fair average. The following table gives the proper sizes of hot and cold air ducts and sizes of registers for both steam and hot-water indirect heating under ordinary conditions. TABLE X INDIRECT WORK. SIZES OF COLD AND HOT Am DUCTS AND REGISTERS FOR FIRST FLOOR INDIRECT HOT WATER INDIRECT STEAM Sq. ft. of Heating Surface. Sq. in. Cold-air Duct. Sq. in. Hot-air Duct. Size of Register. Sq. ft, of Heating Surface. Sq. in. Cold-air Duct. Sq. in. Hot-air Duct. Size of Register. 26 36 48 8X12 13 36 48 8X12 52 54 72 9X12 26 54 72 9X12 78 72 96 10X14 39 72 96 10X14 104 96 120 12X15 52 90 120 12X15 130 108 144 12X19 65 108 144 12X19 156 126 168 14X22 78 126 168 14X22 182 144 192 14X24 91 144 192 14X24 208 162 216 16X20 104 162 216 20X20 234 180 240 16X24 117 180 240 20X24 260 198 264 20X20. 130 198 264 20X24 286 216 288 20X24 143 216 288 24X24 312 234 312 20X24 156 234 312 24X24 NOTE. Registers and ho':-air ducts to upper floors should be from 25 to 30 per cent, smaller than for first floor as given above. It is well to be generous in the size of flues, as if properly dampered they may be reduced at any time as desired. There are two good methods in vogue of hanging a stack of indirect radiation. Fig. 99 shows one method, that of eye bolts screwed into the joists, suspending a cross bar of pipe on which the stack rests. Fig. 100 shows another method and one which we favor, owing to the fact that the weight of the radiator is dis- tributed across several joists. Heavy stacks suspended on a pair of supports or hangers in this manner will not weaken or strain the flooring as much as when the former method is employed. Casings may be made of wood lined with tin or of sheet iron, as may be desired. A casing of galvanized iron with joints seamed LOCATING RADIATING SURFACES 95 or bolted together is without doubt the best method to use, as it not only presents a neat appearance, but is the most durable. Fig. 101 shows the method of setting a direct-indirect radiator FIG. 99. Method of supporting indirect stack. BOX BASE DAMPER FIG. 100. Another method of supporting indirect stack. FIG. 101. Method of setting direct-indirect radiator. and while there are several modifications of this style, the principle for the setting of all direct-indirects is the same. The wall boxes, Fig. 102, are of standard size, conforming to brick measurements and are furnished by all manufacturers of ra- FIG. 102. Wall box for direct-indirect radiator. diators. The radiator itself is of the ordinary direct pattern. It is fitted with and rests on a box base. This base -is provided with a damper and is connected to the cold-air wall box by a boxing 96 PRACTICAL HEATING AND VENTILATION made of galvanized iron or tin. Fig. 103 shows a base of this kind. By closing the damper to the cold-air duct and opening the damper in the box base, the radiator may be used as a direct radiator. This FIG. 103. Box base for direct-indirect radiator. is of importance in connection with the heating of a cold room or when ventilation is not necessary. The " flue " type of radiator is the best design for direct-in- direct, owing to the length of air travel through the flues between FIG. 104. Flue type of direct-indirect radiator. the sections. Fig. 104 shows a section of a flue radiator. By refer- ence to the following chapter our readers will learn why we believe a radiator of this type is best adapted for work of this character. CHAPTER X Estimating Radiation HAVING considered the various forms of radiating surfaces and their proper location, we have now reached that part of the work which the steam fitter frequently finds confusing, viz. : the estimating of radiation. This requires careful thought and study on the part of the steam fitter, as no two jobs of heating are alike, excepting, of course, there be two buildings erected from the same plans; therefore, each job or contract for heating must be consid- ered separately and the radiation estimated accordingly. As a rule, all radiation is first estimated as direct, that is to say, the amount of direct radiation necessary to do the work required, and certain percentages are added if the radiation or any por- tion of it is to be direct-indirect or indirect. Many good rules are in vogue for estimating, any one of which will give proper results if applied with good judgment, but just as there are exceptions to all other rules, so that it is in estimating radiation. To use good judgment it is necessary that we should understand something of the cooling surfaces in a room or build- ing, the action of the heat from a radiator upon the air in a room and the heat loss from a radiator under certain varying con- ditions. The principal cooling surfaces of a room are the exposed or exterior walls and the glass surface (windows) and outside doors. A room with two sides exposed, for instance, a corner room, will require more radiation than an intermediate room with but one wall exposed, while a room having two windows and an outside door will require correspondingly more radiation than a room with but one window. Just how much more is determined by rule. Again, if there be no objects such as trees or adjacent buildings to protect any one of the sides of a house, the north, west, or 97 98 PRACTICAL HEATING AND VENTILATION northwest rooms will need more radiating surface than the rooms on the south, east, or southeast sides of the building. The rea- son for this is readily seen, as practically all the chilly winter winds come from the north, west, or northwest. A frame building without weather board or paper used in its construction requires more radiation than one with this additional protection, and either one requires more than a brick or stone building. FIG. 105. Circulation of air by direct radiator. As to the action of the heat from a radiator upon the air of the room, the radiator, if direct, should be placed in the coldest place in the room, as stated in the preceding chapter, for the rea- son that it meets and warms the cold air entering through the out- side walls and windows, tempers and heats it, causing it to cir- culate or turn in the room, thus warming all portions of the room to a uniform temperature. Fig. 105 shows the action of a direct radiator upon the air ESTIMATING RADIATION 99 in a room, the arrows indicating the direction of the air currents. We note that the heated air first rises to the ceiling where the air of the room is lighter than below, then passes to an inside wall, where it is forced downward and drawn across the floor again to the radiator, where it receives the same treatment as before, the rapidity of the circulation depending upon the volume of heat from the radiator. Note also the downward draught of the cold air entering at the window, and how it is prevented from entering the i/Screen FIG. 106. Circulation of air by indirect radiator. body of the room. Should the radiator be placed along an outside wall between two windows, or in a corner, the cold air entering through the windows would pass downward to the floor and then be drawn along the floor to the radiator. Heat, or more properly, heated air, from an indirect radiator passes directly to the ceiling, then across to the windows or out- side wall where, as it cools, it settles to the floor and is drawn across the floor again to the register as shown by Fig. 106. It 100 PRACTICAL HEATING AND VENTILATION is for this reason that churches or rooms with very high ceil- ings are very difficult to heat with indirect radiation without the assistance of some direct radiators to aid in turning the air of the room. Where direct-indirect radiation is placed the action upon the air in the room is similar to that of the direct radiator as shown by Fig. 105. Rules for Estimating Radiation Some one has aptly said, " We gain knowledge and profit by the mistakes of others," and truly this is exemplified in figuring radia- tion. Many years ago the writer was taught to estimate radiation by the following rule: For Steam To ascertain the amount of radiation required find the cubical contents and divide the result by the following factors Living rooms, ordinary exposure 50 Living rooms, extraordinary exposure 40 Bath and dressing rooms 40 Staircase halls 50- 70 Sleeping rooms 55- 70 School rooms 60- 80 Churches, theaters, halls, etc 65-100 Factories 75-150 For Hot Water Add one third to the result obtained for steam. For direct-indirect, add twenty-five per cent, and for indirect, add fifty per cent. It will readily be seen that the results obtained by this old rule, which is now almost entirely obsolete, were anything but cor- rect, and unless the person using the rule was thoroughly con- versant as to the requirements of certain rooms, or was endowed with extraordinary good judgment, many errors would result. Yet many heating contractors are to-day using this rule or some other " rule of thumb " just as antiquated. ESTIMATING RADIATION 101 Some Dependable Rules Baldwin's Rule: Divide the difference in temperature, be- tween that at which the room is to be kept and the coldest outside atmosphere, by the difference between the temperature of the steam pipes and that at which you wish to keep the room, and the product will be the square feet, or fraction thereof of plate or pipe surface to each square foot of glass (or its equivalent in wall surface). Thus: Temperature of room, 70 degrees; less temperature outside, ; difference, 70 degrees. Again : Temperature of steam pipe, 212 degrees; less temperature of room, 70 degrees; differ- ence, 142 degrees. Thus: 142 -=-70 equals 0.493, or about one- half a square foot of heating surface to each square foot of glass, or its equivalent. The above covers only the exposure of the room and is for a well-built building. Loose windows, poor construction, etc., must be taken into consideration and the proper allowances made. Another rule (and the one used by the author for quick fig- uring) is that of Mills, and briefly stated, is as follows: To find the amount of radiation required to heat a room with low-pressure steam to 70 Fahr. when the outside temperature is at Fahr., allow one square foot of radiation for each 200 cubic feet of contents, one square foot of radiation for each 20 square feet of outside wall surface, and one square foot of radiation for each 2 square feet of glass surface (counting outside doors as glass surface). The product of these results will be the amount of radiation required. For hot water add 60 per cent to this result. As an example consider a room 12' X 15' in size, having a 10 ft. ceiling. The cubical contents, found by multiplying 12 X 15 X 10, equals 1,800 cu. ft. One 12 ft. side is exposed wall: 102 PliAOTIC'AL HEATING AND VENTILATION 12 X 10 = 120 sq. ft. of exposed wall surface. The room has two windows 3 X 6' : 3 X 6 = 18 X 2 = 36 sq. ft. of glass surface. 1,800 200= 9 120 20= 6 36 2 = 18 Total 33 sq. ft. radiation. For hot water: 33 X 60$ = 19.8 + 33 = 52.8 sq. ft. of ra- diation required. It is the custom of the author to add 25^ to the amount of direct for direct-indirect, either steam or hot water, and for in- direct to add 50^ for steam and 60^ for hot water. While there are many rules for estimating* and some of them possibly a little more accurate than the above, we consider either Baldwin's or Mills's rule to be the simplest and best, as they are free from complicated methods not readily understood. The author has found that it was excellent practice to increase the radiation somewhat on the north and west sides of a building, also that when a building is heated intermittently (as is the case with some churches, halls, etc.) the radiation should be increased 25^ over and above the normal amount required should the build- ing be heated continuously. It is well to become familiar with two or more rules, using one as a check upon the other. CHAPTER XI Steam-Heating Apparatus IN one of the early chapters of this book we gave a brief his- tory of steam heating and its introduction in this country. We shall now take up the many various systems and consider the advantages or disadvantages of each, showing also the various styles of piping. The early method of heating by steam was with the two-pipe system, small sizes of pipe being used and a high pressure of steam maintained. As our knowledge of steam heating increased, larger piping and a lower pressure were made use of. At the present time there are many buildings, such as factories and offices, or commercial buildings, where a medium or compara- tively high pressure is used, the steam being generated at high pressure by the boilers and reduced for use in the heating system. On work of this character the water of condensation is returned to the boiler by return steam traps or by a pump. For the heating of residences and small buildings, we use what is called a " gravity system," the pressure of steam being from one to five pounds, the condensed steam returning to boiler by its own gravity. The boiler is located below the level of all mains and radiators. It is of this latter method that we shall treat, illustrat- ing and explaining each system. Low-pressure gravity steam heating may be divided into sev- eral systems or styles of construction, as follows : (a) The one-pipe system, where the radiators are connected by a single pipe which is used both as flow and return. (b) The two-pipe system, where each radiator has a separate flow and return pipe. This system also necessitates a double sys- tem of cellar piping. These two methods may be subdivided into several styles or systems, viz. : 103 104 PRACTICAL HEATING AND VENTILATION (a) The Circuit System. (b) The Divided Circuit System. (c) The One-pipe System with Dry Returns. (d) The Overhead System. Fig. 107 illustrates the regular circuit system. The steam main rises from the boiler as high as possible, or as high as circum- FIG. 107. Circuit system of steam heating. stances or height of basement will permit. This is the high point of the system, so far as the steam main is concerned. From this point the main makes a circuit of the building, as shown by illus- tration. This circuit is made at a distance of from two to six feet STEAM-HEATING APPARATUS 105 from basement wall (circumstances governing this distance), the main pitching downward from the boiler from %" to 1" in each ten feet of length. In making the circuit of the basement, the main is carried to a point as near to the boiler as is possible. At this point a reducing elbow is placed on the end of the main, re- ducing one or two sizes. Connection is then made with return opening of boiler. This reducing elbow should be tapped for an air vent and an automatic air vent be placed on the same. As the main acts as a steam reservoir to supply the various radiators, it is well to free it of all air, in order that the steam may be supplied to all radiators at the same time, thus allowing them to ^45 ELBOW ^-BRANCH TEE FIG. 108. Branching from main with 45 elbow. heat uniformly. The automatic air vent placed on the elbow at the end of the main accomplishes this purpose. The various branches should be taken from the main by the use of a nipple and a 45-degree elbow, as shown by Fig. 108. As a general rule, the branches should be one size larger than the vertical pipe or " spud " supplying the radiator valve, or one size larger than the risers which they feed. Most of the old-time steam fitters, as well as many fitters of the present day, make a practice of taking the connection for branch from the top of the main. This practice is wrong, as the con- densation returning through the branch to the main drops directly into the steam supply, saturating and cooling it. Fig. 109 illus- 106 PRACTICAL HEATING AND VENTILATION trates this. We may add, for example, that a main where all the branches are taken off with the use of 45-degree elbows, as shown by Fig. 108, will do 25^ more work, and prove 25^ more economi- cal than if taken off main from the top. Fig. 108 also shows how the water of condensation joins that in the main without interference with the steam, when 45-degree el- bows are used. The main on a circuit job of heating should not be reduced in size, but should be carried full size to point where air vent is used. The principal reason for this is that it is constantly being reduced ^-BRANCH "^90 ELBOW ^NIPPLE VTEE FIG. 109. Branching from main with 90 elbow. in area by the water of condensation from the various radiators entering it, so that its area at the end may not be more than one half the full capacity of the pipe. The branches should have a pitch upward from main of at least 1" in 5 feet of length, and a greater pitch is desirable. Special elbows, called pitch elbows, for use on end of branch, in order to throw the vertical spud or riser straight, may be purchased from those who deal in steam-fitting supplies. Where the circuit system can be used to advantage, we would recommend it on account of its utility and good appearance. For STEAM-HEATING APPARATUS 107 an L-shaped building, it is necessary to take a separate loop from the main circuit, as shown by Fig. 110; otherwise the work is similar to the single loop. FIG. 110. Circuit system of steam heating with loop. The Divided Circuit System When installing a steam-heating apparatus in a long building where the boiler is located near the center of the basement, and on either side of the same, we may use what is called the Divided 108 PRACTICAL HEATING AND VENTILATION Circuit System, as illustrated by Fig. 111. The convenience of installing this system can be readily seen from the illustration. In installing this system and also the Single Circuit, it is well to keep the end of mains at least 14" above the water line of the boiler. With the Divided Circuit System it is necessary that an auto- matic air vent be placed on the end of each loop. The returns should be connected together below the water line of the boiler, as shown by illustration. The One-pipe System Dry Returns When it is necessary to install steam heat in a long, narrow building, such as one side of a double house, where the radiators are all placed along the outside wall, this system, as illustrated by Fig. 112, is particularly adaptable. The flow pipes, as shown, pitch downward from the boiler to end of main. On the end of main a reducing elbow is placed. Into this elbow is connected a close nipple with a 90-degree elbow on the end of same, and from this elbow the return is taken dry to the boiler, as shown. These elbows should be " thrown " or turned upward until the top of the return is level with the bottom of the main, in order to gain head room. A short piece of pipe, with crooked thread on one end, should be used in starting the return ; the longer pipe should be attached to this piece with an ordinary coupling. In this manner the return may be taken to boiler almost directly under and par- allel to the main, making a good appearing and workmanlike job. At a point near the boiler, elbows should be placed on end of returns and drop made to return opening of boiler. These elbows should be tapped for air vent and automatic air vents placed on same, Note the coil shown on illustration. All pipe coils should be connected " two pipe " with return connected below the water line of the boiler. The Overhead System The Overhead System of steam heating is necessarily a combina- tion of the one and two pipe systems and it may have either a wet or a dry return, although the wet return is by far preferable. We illustrate by Fig. 113 an adaptation of the overhead system STEAM-HEATING APPARATUS 109 110 PRACTICAL HEATING AND VENTILATION STEAM-HEATING APPARATUS 111 and show the many different methods by which the radiators may be connected. The riser or risers (there may be more than one) rise directly to the top floor or attic of the building and here branch in the several directions necessary to feed the various drop risers sup- plying the radiators. The branches connecting these risers are PRACTICAL HEATING AND VENTILATION A STEAM-HEATING APPARATUS 113 taken from the side of the main. Should it be necessary to run the main any considerable distance from the boiler in the basement be- fore rising to top of building, it is well to " heel drip " the elbow at bottom of the riser and connect the drip with the wet return. At the left of the illustration in the basement we show one method of creating a false water line, in order that the returns from risers in an unexcavated portion of the basement may be con- nected into a wet return. We shall in a later chapter illustrate and describe the false water line more fully. At the right of the illustration we show in the basement a wall radiator for heating a basement room, which is warmed par- tially by steam, above the water line of the boiler, and partially by the water of condensation, below the water line of the boiler and is connected in such a manner, without valves, that it might be designated as a cooling coil. The illustration shown is composed of three sections of wall radiation, although a pipe coil could be used in the same manner. The Two-pipe System Illustrated by Fig. 114 we show the Two-pipe System of steam heating. This system has been discarded generally on ordinary work, being succeeded by the One-pipe System, although it still has some adherents among the fitters. Smaller piping for both flow and returns and flow and return risers is used for this system than for either of those already de- scribed. The cost of installation will, however, exceed that of either style of the single-pipe systems. It is customary when using the FIG. 115. Eccentric fittings the right method. two-pipe system, to reduce the size of the main as the various radiators are taken off. We would caution against reducing the main too rapidly, as so much friction would result that it would be necessary to carry a considerable pressure at the boiler in order to supply the radiators at the far end of the system and this 114 PRACTICAL HEATING AND VENTILATION would thereby destroy the economical features of the job. When- ever the main is reduced, a tee should be used and a drip con- nected to return, or, what is better, eccentric fittings should be used, FIG. 116. Common fittings the wrong method. as shown by Fig. 115. Unless this course is pursued, the water of condensation will lodge in the main (see Fig. 116) and cause " water hammer " or pounding in the piping. Advantages of Steam Heating The advantages of steam heating over other systems, not consid- ering the patented vacuum or vapor systems, are: (1) there is less liability of damage by frost; (2) smaller radiators and piping are used ; (3) rooms are more quickly warmed and cooled, and (4) where a system of ventilation is used, the air is more quickly purified. By the use of automatic damper regulators, safety valves, etc., the danger of explosion has been practically eliminated, so that now steam may be used with as great a degree of safety as any other system. TABLE XI SIZES OF STEAM MAINS ONE-PIPE SYSTEM. TWO-PIPE SYSTEM. Size of Radiation Supplied. Size of Steam Main. Radiation Supplied. Flow. Return. IW 125 to 250 sq. ft. W W 250 to 400 sq.ft. CfH 250 to 400 " " 2" W 400 to 650 2V 2 " 400 to 650 " " <&/<>" 2" 650 to 900 3" 650 to 900 " " 3" 2^2" 900 to 1,200 &w 900 to 1,200 " ' 3^" y 1,200 to 1,600 4" 1,200 to 1,600 " * 4" 3" 1,600 to 2,000 w 1,600 to 2,000 41^" 3^" 2,000 to 2,500 5" 2,000 to 2,500 5" 4" 2,500 to 3,500 6" 2,500 to 3,500 6" 4H" 3,500 to 5,000 7" 3,500 to 5,000 7* 5" 5,000 to 6,500 8" 5,000 to 6,500 8" 6" 6,500 to 8,000 CHAPTER XII Exhaust Steam Heating WHILE exhaust steam for many years has been used for heat- ing factories, its use in heating office and public buildings, stores, etc., may be said to cover a period of probably the past ten years. We mean by this its general use, as in the larger cities it has been more or less employed for the past score of years. Of later years numerous improvements have been made in utiliz- ing and controlling the steam, both live and exhaust, and the heat- ing contractor or engineer who does not familiarize himself with these new and improved methods is neglecting a very important part of his business education. We now desire to treat only of the value and utility of using the exhaust from the engine and the ordinary method of applying the same for heating purposes. The improved methods will be found illustrated and described in a later chapter of this book. Value of Exhaust Steam It is a lamentable fact that in many factories and business build- ings a very great percentage of the steam from the engines is al- lowed to exhaust into the outside atmosphere. We think we are perfectly safe in saying that over 50$ of the steam produced by the boilers is thus wasted. Could the value of this waste be brought directly and forcibly to the attention of the owners, in such a man- ner as to be thoroughly understood by them, without doubt they would lose no time in taking such steps as would be necessary to stop the loss. The amount of steam used by the average non- condensing engine is but about from 7%$ to 10$ of the amount produced by the boiler ; in other words, the steam exhausted from the engine has practically 90$ of its original energy and value. Should the exhaust be employed in supplying a feed-water heater, 115 116 PRACTICAL HEATING AND VENTILATION five per cent more should be deducted, leaving eighty-five per cent of the original amount available for heating purposes or other uses. Many concerns do not make a practice of heating their feed water, although some of them discharge their exhaust into an open well or tank and thus warm the water supply that is pumped to the boiler. Steam specialties such as feed-water heaters, separators, steam traps, etc., will usually pay for themselves by their saving in one or two seasons, and, when the excess steam is utilized for heating, the saving will equal about one half of the usual coal pile. When there is not a sufficient amount of exhaust steam to supply the heating system, the piping may be so arranged that enough live steam may be introduced into the heating system to make up the deficiency. There are many methods of arranging the piping and fixtures for making use of exhaust steam. We show one of them in the illustration, Fig. 117. Necessary Fixtures In connecting the exhaust to supply the heating system, care must be exercised not to increase the resistance and thus cause back pressure on the engine. A back pressure of from one to three pounds may be readily overcome by a slight increase of pressure at the boiler. A steam main of generous size for the heating sys- tem, as free from right-angle turns (elbows), or bends, as pos- sible, is recommended, and a back-pressure valve should be placed on the exhaust pipe a considerable distance from the engine. The engine delivers steam into the exhaust intermittently, that is, at the end of each stroke, the engine governor admitting only sufficient steam to the engine for the work required of it. It may be " run- ning light " with but a small proportion of the machinery in the factory in use. Thus the amount of exhaust steam delivered to the heating system may not be sufficient, in which case a supply of live steam is admitted to it. This steam supply is admitted at a re- duced pressure, hence a reducing-pressure valve is necessary on the live steam connection. A valve partially open or " throttled " may be used, but it is much better to have a reducing valve set to reduce to the pressure required. EXHAUST STEAM HEATING 117 HHHHHHHHHHHH 118 PRACTICAL HEATING AND VENTILATION In the exhaust as delivered by the engine, there is considerable water, which is more or less filled with particles of lubricating oil, small particles of dirt and packing. This must be removed before the steam is admitted to the heating system ; consequently a sepa- tor which will separate both oil and water is placed on the exhaust pipe before it is connected to the heating system. A small drip pipe or waste should be connected from the bottom of the separator to a trap, which will discharge outside the building or to a sewer. Were it not for this separator the oil, etc., in the exhaust would pass through the return of the heating system to the pump or trap feeding the boiler. This must be guarded against. Refer- ence to Fig. 117 will show in general the fixtures used and method of connecting the same. The exhaust may be taken direct from the engine to a large closed tank, which is provided with baffle plates for separating the oil and other impurities from the steam. This is called a " grease tank " and a drip should be taken from the bottom to a trap empty- ing to sewer in the same manner as though taken from a separator, as before described. A relief pipe may be used, connecting the tank with back-pressure valve. This tank should be placed at the top of the heating system, and from it connection to heating main should be made. ' Different engineers have various methods of making connec- tions. We have found that it is well to have the heating main connected as high above the engine as possible. An overhead sup- ply or overhead system is preferable to all others. When con- necting valves and fixtures, it is well to make frequent and gen- erous use of flanges, as these will be found of great convenience when changing valves or making repairs. Heating Capacity of Exhaust Steam For estimating the amount of exhaust steam available from a certain size of engine, many rules, more or less complicated, have been given by various authorities. For the practical use of the fitter would say a safe rule is to allow from 100 to 125 feet of direct radiation (pipe and fittings covered, or figured as radiation) per H. P. of the engine. Thus a 100 H. P. engine, working to its EXHAUST STEAM HEATING 119 regular capacity, should exhaust sufficient steam to heat the nec- essary feed-water for the boiler or boilers and have sufficient excess to heat 10,000 sq. ft. of direct radiation. Of the character of steam appliances or specialties we shall treat in a future chapter. CHAPTER XIII Hot-water Heating THE growth of hot-water heating in this country, as a means of warming our homes, has been little short of phenomenal. The personal experience of the writer, covering a little less than twenty years, shows that, where twenty years ago for residence heating there were four or five times as many steam boilers installed as there were hot-water heaters, at this period the great percentage is in favor of hot water. While we have no accurate data on the subject, the records of two or three manufacturers of heaters show a ratio of about ten or eleven to one in favor of hot water. Steam is, as a rule, used for heating factories, business build- ings, public and semipublic buildings, although for this class of work hot water is beginning to be more generally employed. There are two general systems of hot-water warming, namely, " low pressure " and " high pressure." It is the former method which is in general use. Low-pressure hot-water heating has many advantages to recommend it for residence work. Very little attention to the apparatus is required, aside from coaling the heater and removing the ashes. This is of considerable importance, however, as the man or men of the family may fre- quently be compelled to absent themselves from home for extended periods and the care of the heating apparatus be left to inexperi- enced hands. Hot-water heat is very easily controlled and an even tempera- ture can be readily maintained. Regulators are now used with hot-water apparatus, and it is possible to so adjust these that any desired temperature can be maintained within the rooms. As to consumption of fuel, the hot-water apparatus is the most economical of any of the various heating systems. As the average hot-water apparatus works at a temperature ranging from 100 to 120 degrees in mild weather, and from 160 to 120 HOT-WATER HEATING 121 180 degrees in cold weather, the heat from it is very mild and the at- mosphere is not robbed of any of its healthy qualities. Some years ago it was customary to maintain a temperature of from 180 to 212 degrees. Experience has demonstrated that the greatest economy and most satisfactory heat are obtained by carrying the water at a much lower temperature, and the heating contractor of to-day, as a rule, places sufficient radiation in the building to warm the same with the water at the lower temperature. Low-pressure hot-water heating may be divided into three sys- tems, or methods of piping, viz. : (a) The regular two-pipe system. (fo) The overhead system. (c) The single main or circuit style of piping. The Two-pipe System The two-pipe system is the oldest of the various styles of pip- ing for hot water, hence is best understood by the fitter and heating contractor, and is more generally used than either of the other systems. The flow pipe, or pipes, of sufficient size to feed the necessary amount of radiation, are carried to such a height above the heater as to allow of a proper pitch of the main. On the top of this riser an elbow is placed and the lateral pipe or main is run with a pitch upward of from one half to one inch in each ten feet of length to the end of the system, or to the branch supplying the radiator farthest from the boiler. The general design of this system is shown by Fig. 118. We show several styles of radiator connections, and attention is called to the manner of supplying the branch at the end of the main, the elbow on the end being tipped to an angle of 45, and a 45 elbow and nipple used in making the connection. This manner of con- necting the branch is a help to the circulation at this point and the radiator will heat better than when the connection is made with 90 elbows. All tees on the mains supplying branches should be tipped to an angle of 45 degrees and the branch supplied by using a nipple and 45 elbow. Many fitters seem to think that by taking branches PRACTICAL HEATING AND VENTILATION HOT-WATER HEATING 123 I 5. 8 I PRACTICAL HEATING AND VENTILATION out of the top they are increasing the circulation, but such is not the case, as every 90 elbow used on hot-water work increases the friction and impedes the circulation. Any " choking " of the cir- culation necessary to make radiators heat uniformly should be done by using a reducing elbow at the end of the branch. Great care should be taken not to reduce the size of the main too rapidly. Frequently the reducing in size of a short piece of pipe between two tees supplying branches, has " killed " the circulation beyond the point of reduction. As a better means of understanding this system we show by Fig. 119 a basement plan of the cellar piping of a hot-water ap- paratus. For convenience in illustrating we have shown branches taken from top of main; 45 connections are preferable, as ex- plained above. Where the flow pipe is divided in order to feed radiators in opposite directions, it is well to use double elbows. See Fig. 120. In fact, this fitting should be employed on all pip- ing either for steam or hot water. The tee as used " bull head " not only increases the friction but frequently is the means of caus- ing an uneven circulation in the piping supplied by it. TABLE XII SIZES OF MAINS TWO-PIPE HOT-WATER SYSTEM Size of Main. Radiation Supplied. IV" 125 to 175 to 300 to 475 to 700 to 1,000 to 1,400 to 1,750 to 2,200 to 175 sq. ft. 300 475 700 1,000 1,400 1,750 2.200 3,000 2" 3" 4'" 5" 6" There seems to be quite a difference of opinion among heating engineers as to the size of mains necessary for hot-water heating, many of them advocating much smaller piping than is given in the above table; that is, they increase the amount of radiation a cer- tain size of pipe will supply by from one third to one half of the amount as given above. HOT-WATER HEATING 125 In an experience covering nearly a score of years the writer has used both large and small piping, and we find that while the character of the work to a great extent governs the size of pipe to be used, it is well to be generous in the size of piping, par- ticularly for the main supply pipes. For all ordinary two-pipe FIG. 120. The double elbow. work we consider the sizes as given in the schedule conservative. Friction should be avoided and as the friction in a horizontal pipe is much greater than in a vertical pipe, the horizontal pipe must of necessity be larger than the vertical to accomplish the same service. The Expansion Tank As water heated to 180 or 212 degrees expands from one twenty-fourth to one thirtieth of its volume, it is necessary on hot-water work to make some provision for the increased volume of water and for this purpose we make use of a tank, which we call an " expansion tank." There are several methods of connect- ing this tank w r ith the hot-water system. It should, however, in each instance be located at least three feet above the highest radia- tor on the system and the expansion pipe should be connected to the return pipe of the radiator. The vent pipe leading from the top of the tank should be carried through the roof above the tank, or through the side of the building into the outside atmos- phere. This vent pipe may also be used as the overflow; in case the system overflows by reason of being filled too full, the excess water will empty on the roof or outside the building. When the expansion tank is placed in the bathroom of a resi- dence, many fitters make a practice of carrying the overflow into 126 PRACTICAL HEATING AND VENTILATION the closet tank, while others take the pipe to a basement drain. The former method is poor practice, and the latter a waste of mate- rial entirely unnecessary. By Fig. 121 we show the simplest form of connecting the ex- pansion tank. When this style of connection is used, the tank must be located in a room which is heated, or where there is no liability of freezing. < -VENT pipq RETURN FROM HIGHEST RADIATOR/ GAUGE FLOW AND RETURN CONNECTED TO HIGHEST RADIATOR FIG. 122. Connecting ex- pansion tank circulat- ing water to tank. FIG. 121. Connecting expansion tank- common method. Fig. 122 shows a method of tank connection where the water is circulated to the tank or directly underneath it. In employing this style of connection, one pipe must be connected to the flow and the other to the return pipe of one of the highest radiators on the system. When it is necessary to place the tank in a cold room or an exposed place, we recommend the connection as shown by Fig. 123. We also recommend that nothing less than 1" pipe HOT-WATER HEATING 127 be used for the connections. With this method the water in the tank is circulated or warmed. Either of the latter two methods .OVERFLOW WATER SUPPLY FIG. 123. Connecting expansion tank circulating water in tank. of connection will prove of assistance in keeping air out of the system. FIG. 124. Automatic expansion tank. A later style of expansion tank and one which has met with favor is the automatic expansion tank which operates with a ball 128 PRACTICAL HEATING AND VENTILATION cock and float. Fig. 124 shows an interior view of the tank. It is made of wood and has a copper lining. They are also constructed of steel and of a form similar in appearance to the regular style of tank. That illustrated has much the appearance of the regular closet tank and when placed in a bathroom or other occupied room is commendable for its neat appearance. No valves of any de- scription should be placed on any of the expansion-tank connec- tions. They are not only unnecessary, but are liable to be closed (by error) and the system thereby be put under pressure, with liability to damage by explosion. Water Connection The water connection to a hot-water heating apparatus should be made by connecting into the return pipe at the rear of the boiler. Where there is no regular water supply and it is necessary to fill the system by hand or with a pump, the connection must of neces- sity be made at the tank or the top of the system. Table of Expansion-tank Sizes The following table gives the proper size of expansion tank for any hot-water heating apparatus up to 6,000 sq. ft. of radiation. TABLE XIII Capacity. Size. 300 sq. ft. rad ation 10 gal. 12X20" 500 " 15 12X30" 700 " 20 14X30" 950 26 16X30" 1,300 32 16X36" 2,000 42 16X48" 3,000 66 18X60" 5,000 82 20X60" 6,000 100 22X60" The Overhead System A style of piping for hot water which, when it has been prop- erly erected, has met with much favor, is the so-called " overhead system." We do not hesitate to say that it is the best method of hot-water piping in use to-day, and while it is not adaptable HOT-WATER HEATING 129 130 PRACTICAL HEATING AND VENTILATION to all classes of buildings, there are many, such as flat or apart- ment buildings, store and office buildings, hotels or factories, where the character of construction, manner of dividing the space into living rooms, offices, etc., render the overhead system particularly serviceable. There are many advantages to be gained by the use of this system, the principal one being that but one riser or drop pipe is necessary for supplying a line of radiators, and also that the circulation of the water is both positive and rapid. No air vents are necessary at any point on the system, as the piping is so arranged that all air works to the top of the system into the expansion tank and through this to the atmosphere, thus keeping the system free from air at all times and as the removal of air from the heating system is one of the great troubles of the steam fitter, much good has been accomplished by this alone. MAIM .BRANCH DROP RISER FIG. 126. The overhead system branch from main. In illustrating this system (Fig. 125) we show in detail some of the many methods of connecting the radiators and the general mode of piping. The main flow pipe is taken from the top of the heater, as with the regular two-pipe system, and run to some con- venient point to allow it to be run vertically to the attic or top floor of the building. This should be the high point of the system and from this point the connection to the expansion tank should be made. From the top of the main riser, the various branch mains are run. These have a drop of at least one half inch in each ten feet of length and from these mains the branches supplying the drop risers are taken. Those shown on Fig. 125 are taken out of the side of the main. We favor a 45 connection as shown by Fig. 126. The size of the drop risers depends entirely upon HOT-WATER HEATING 131 the amount of radiation fed by them. As a rule, they should be larger at the top than at the bottom, reducing gradually as the various radiators are supplied. The radiator connections from the risers should be smaller at the top of the building, increasing in size (the same size of radiators considered) toward the bottom of the riser. FIG. 127. The O. S. distribu- ting fitting. FIG. 129. Straightway valve with union. FIG. 128. Application of O. S. distributing fitting. In the basement the risers are connected into returns in the same manner as with the regular two-pipe system, these returns being increased in size as the various branches are connected until finally the water is returned to the boiler through approximately the same size of pipe as the main riser. PRACTICAL HEATING AND VENTILATION An advantage where this system is used and one which should not be overlooked, is the ability to circulate the water through Branch out of Tee Main Return p IG jgQ Connecting radiator on a level with heater. and supply heat to radiators located on the same floor as the heater, or even lower than it. This is by reason of the weight of the FIG. 131. Connecting radiator on a level with heater. HOT-WATER HEATING 133 water or pressure on the system, there being one pound pressure for each two feet of height of the water in the system. We have shown by Fig. 125 several methods of using the ordinary tees on the riser from which connections to radiators are made. We also show on the two risers, at the right hand of the illustration, a special fitting (Fig. 127) known as the " O. S." fitting and we commend it to the use of all heating contractors as an aid to the reduction of friction and a quickening of the circulation, and also on account of the labor saved by its use. In order that it may be better understood, we show an enlarged riser (Fig. 128), illus- trating two radiators connected by the use of this fitting. A style of radiator valve which is particularly adaptable for use with this system is shown by Fig. 129. It is known as the FIG. 132. Base elbow. " straightway " valve, and is a quick-opening valve. As its name indicates, it is for use on a straight pipe or connection. When connecting radiators on or below the level of the heater, care must be taken not to make a connection which will get air bound. If the connection is taken from one of the overhead return pipes, we recommend that it be done as shown by Fig. 130. If taken from the drop riser it should be connected as shown by Fig. 131. The sizes of mains for the overhead system are practically the same as for the two-pipe system, although the main riser may be somewhat reduced in size. When this riser exceeds 3" in size, it is well to use a special elbow at its base (Fig. 132). This should be supported by a brick or cement pier, in order to relieve the building of the weight of water in this portion of the apparatus. 134 PRACTICAL HEATING AND VENTILATION Expansion Tank Connections The expansion tank should be placed somewhat higher than the fitting on the top of the main riser. A very simple method of con- necting the tank is shown by Fig. 133. The tank should be placed on a support or framework of sufficient strength to make it stationary. No gauge on the tank is necessary, although many fitters use it. Another method is that shown by Fig. 134. The tank is VENT AND OVERFLOW- EXPANSION TANK FIG. 133. Expansion tank connection overhead system. suspended in a horizontal position by iron straps hung from the roof timbers, which are strengthened sufficiently to support the ex- tra weight. The overflow may empty into a pan, from which there is a drip to the sewer in the basement. As is the case with the regular two-pipe system, no valves should be placed on the con- nections to the tank. There are several modifications of the overhead system, which lack of space will not allow us to illustrate. There is one method, HOT-WATER HEATING 135 ROOF :f#K^a ; FIG. 134. Expansion tank connection with drip overhead system. EXPANSION TANK^ Ij/VENT AND OVERFLOW FIG. 135. Modified overhead system. 186 PRACTICAL HEATING AND VENTILATION however, which we should be familiar w r ith. It is frequently nec- essary in heating a store or small building to place both boiler and radiators on the same floor. To do this successfully, the main flow pipe should be run on the ceiling as shown by Fig. 135. The illustration shows an elevation plan without the branch connections. The branches should be taken out of the side of the main. The drop pipes supplying radiators should be connected into the top of one end of the radiator, the return being taken from the bottom of the opposite end. The expansion tank should be hung horizon- tally from the ceiling, with vent and overflow to the roof. No air vents are necessary, as all air in the system works out through the expansion tank. The work may be put under pressure, if desired, by sealing the tank and using a safety valve, as described in a later chapter. The Circuit System of Hot-water Heating The circuit system commonly called the " single-main system," has in the past few years gained considerable favor among heating contractors. A single main pipe, which also acts as a return, is taken from the top of heater to a point as high as desired under the first floor joists. From this point the connection to expansion tank is made. This main pipe is then run around the basement, in a circuit, near to the ceiling and with a gradual pitch from the heater, which should never be less than % inch in each 10 feet of length, but may be more, if desired. This main, which is of extra large size, supplies all of the branches feeding the radia- tors on the first floor or risers to the floors above. The flow pipes or branches are taken from the top of the main, the returns enter- ing at the side. After supplying the various radiators, the main is run directly back to the heater, where it drops and is connected into the return opening of the same. The main must never be reduced, but should be run full size until it enters the return of the heater. Illustration Fig. 136 shows a general view of this system of piping. The fittings shown on the main, which supply branches, are of three kinds. Those marked A A are the regular tee fittings; those marked B B are the Eureka fittings, an enlarged view of which is shown by Fig. 137. This is a single fitting HOT-WATER HEATING 137 PRACTICAL HEATING AND VENTILATION used for connecting both flow and return, the flow leaving the top of the main and the return entering the bottom. It is as easily placed as the regular tee and the saving in labor and cutting of threads is considerable. Those marked C C are the O. S. fittings for use on single-main work and they divide the Return Flow Return Flow Full View Sectional. View FIG. 137. Eureka combination fitting. circulation in the same manner as the regular O. S. distributing fitting. Yet another style of fitting for use on the main of a circuit job is known as the " Phelps Ideal " fitting, as illustrated by Fig. 138. This fitting is quite like a tee with side outlet tapped eccen- tric. The flow is taken from the top of main and the return re- FIG. 138. Phelps combination fitting. enters it at the side on a level with the bottom of the main. This is a much better fitting to use than the regular tee, as one fitting on the main does the work of two, saving thread cutting and labor, and it also has the advantage of delivering the return circulation lower down in the main. HOT-WATER HEATING 139 The branches should have an upward pitch from main; also, the radiator connections are made the same as for the regular two- pipe system. We have found it excellent practice on work of any considerable size to increase the size of the radiators somewhat, that are con- nected on the last two sides of the circuit. The water in the main being cooled somewhat before it reaches this part of the system, it is necessary to provide more radiation in order that all portions of the work wall heat evenly. The sizes of the branches may be somewhat smaller nearest the boiler than those toward the end of the main. It will be found that this system of piping will prove most efficient and acceptable when properly proportioned and erected. TABLE XIV SIZE OF MAIN FOR ONE PIPE HOT WATER Size of Main. Direct Radiation Supplied. 2 inc &A 3 3^ 3* 6 } ies 175s 300' 500 700 1,000 1,200 1,600 2,200 :*! t < < The systems of low-pressure hot-water work we have described and illustrated are the principal forms of this class of work. There are several modifications of each, which it is not necessary to de- scribe as the same general principles of piping, etc., prevail. Hav- ing detailed the character of this work, it is well that we should un- derstand the principles which underlie it, and will therefore treat briefly on the cause of hot-water circulation. Why Water Circulates In answering the question What causes circulation? we say that unquestionably it is heat which causes the w r ater to circulate in a hot-water heating system. When heating by hot w r ater first came into general use in the United States, the writer was taught that 140 PRACTICAL HEATING AND VENTILATION water, being heated, became lighter and when confined in a heat- ing system would ascend to the top and circulate through the pip- ing and radiators. This statement was a gross error, although we believed it at the time, and as we have heard the same state- ment made many times since, it is undoubtedly a very common error. As a matter of fact, hot water will move only when there is a cooler and heavier body of water displacing it and forcing it upward, and were it not for the difference in temperature be- tween the flow and return pipes of a hot-water heating system, there would be no circulation at all. Hot water, as it cools, becomes compact and outweighs the warmer water in the heater, causing it to rise in the system and circulate through the piping and radiators, the difference in the mean temperature of the water as it ascends and descends in the system keeping the circulation constant. The higher the water in the system, the more rapid the circulation, or, stated in another form, the greater the height of the return pipe (in which the cooler water is descending), the more energy and push against the warmer water in the heater and consequently the more rapid the circulation. The height of the flow riser (the ascending water) makes no difference in the rapidity of the circulation of the water in the apparatus, except as the height of the return is increased. The velocity of the flow of water in a heating apparatus depends upon the difference in weight of the ascending and descending columns of water, with due allowance made for friction. There are several methods of determining theoretically this velocity. How- ever, as this book is written only from a practical standpoint, we shall not burden our readers with a discussion of these theories. CHAPTER XIV Pressure Systems of Hot-water Work THE high-pressure system of hot-water heating is not, as a rule, practiced in this country. In England we find it used for various purposes, such as laundry dryers, bake ovens, enameling, etc., the apparatus carrying from 250 to 850 degrees temperature. The piping used is small in diameter and extra strong, or extra heavy in weight. The fittings used are also much heavier than it is our custom to use on heating work. This system was designed and used originally by Mr. A. M. Perkins, of London, Eng., and is known as the " Perkins System." Pressure work as practiced in this country (closed-tank sys- tem), consists of sealing the outlets of the expansion tank, thus putting the apparatus under pressure, a safety valve being used on the overflow at the tank to regulate the same. On ordinary work it is seldom that a pressure exceeding ten pounds is em- ployed, the water in the apparatus at this pressure having a tem- perature of about 240 degrees. This style of work is probably used in greenhouses more frequently than in any other manner, and among its advantages are the use of less radiation, a less volume of water in the apparatus and a more quickly controlled apparatus. For use in heating dwellings or apartments it is objectionable because of the element of danger connected with its operation. Should the safety valve at the expansion tank become inoperative from any cause, an explosion would be the probable result. We have known heating contractors to use this method when they find that too little radiation had been installed to give the temperature required, and frequently to adopt this seeming remedy without giving notice to or obtaining the consent of the owner of the property, which involves not only a dishonest, but a very dangerous practice as well. 141 PRACTICAL HEATING AND VENTILATION The following table gives the temperatures at which water will boil at various pressures (atmospheric), with the equivalent head in feet: TABLE XV PRESSURE. Boiling Point (Degrees). Pounds above Atmosphere. Head in Feet. 212 5 12 228 10 24 240 15 36 250 20 48 259 25 60 267 30 72 274 35 84 280 40 96 287 45 108 292 50 120 297 60 144 307 70 168 316 80 192 324 90 216 332 100 240 338 When it is necessary to place both boiler and radiator on the same floor, as is shown by Fig. 135 in the previous chapter, it is sometimes advantageous to put the work under a moderate pres- sure in order to quicken and maintain a more positive circulation throughout the system. On certain work of this character it is sometimes impossible to run the overhead piping sufficiently high to admit of a free circulation through all of the radiators, those farthest from the heater not working as well as those placed nearer the heater. This is readily remedied by placing the system under sufficient pressure to maintain a free circulation in all parts of the apparatus. Expansion-tank Connections The expansion-tank connections for pressure work may be made in the same manner as for the open-tank system. The open- ing in the tank used for air vent is plugged and the safety valve, which is usually of the lever variety, is placed on the overflow pipe at a point near the tank. PRESSURE SYSTEMS OF HOT-WATER WORK 143 Where a vertical tank is used, the connections should be made as shown by Fig. 139. Where a horizontal tank is used, the con- Safety Valve Overflow Air Cushion o o e o oooooooooooo Expansion/ 1 Pipe ^ FIG. 139. Expansion tank with safety valve. nections should be made as shown by Fig. 140. We show on this illustration the use of a vacuum valve. When the safety valve -Vacuum Valve Safety Valve Overflow O OOOOOOOOOOOOOOOOOOOOOOOQO O O O O O O o FIG. 140. Expansion tank with safety and vacuum valves. 144 PRACTICAL HEATING AND VENTILATION is opened from excess pressure, trouble is frequently experienced in relieving the vacuum at this point, and for this purpose the vacuum valve is used. There are times, however, when the vacuum valve does not relieve the vacuum, due probably to the failure of the valve to operate. A very simple method of relieving the .Check Valve Overflow O O O O O O O D O O O oooooooooooo O 00 Expansion Pipe FIG. 141. Expansion tank with method of relieving vacuum. vacuum without the use of a valve is shown by Fig. 141. It con sists of a check valve used in connection with the safety valve. The connection shown from the check valve into a tee placed on the overflow pipe is made for the purpose of discharging any water which might leak through the check valve. A pressure system of hot-water heating that has been used ex- PRESSURE SYSTEMS OF HOT-WATER WORK 145 tensively in this country is that of Evans & Almirall. This sys- tem is only applicable to large work, as the water is heated by the exhaust steam from engines, pumps or other mechanism requir- ing live steam. The water of the heating system is passed through a tank or heater constructed in much the same manner as a feed- water heater. Its interior is filled with copper tubes through which the water circulates and is heated by the exhaust steam which is carried through the heater and which surrounds the copper pipes. The excess steam, or that which is not condensed in warming the water of the heating system, is discharged into the atmosphere through an exhaust pipe. The water in the heating system is circulated under pressure by a pump, the velocity of the circulation depending upon the speed of the pump, which may be regulated at will by the attendant. Where the exhaust steam is not sufficient to heat the water to the temperature desired, a supplementary heater is used, such a heater being fed with live steam. This system makes an ideal method for the heating of de- tached buildings, or buildings adjacent to that in which the engines, etc., are located, as there is no dependence placed on gravity pip- ing or the use of traps as with steam heat. The temperature of the water may be carried just as high as the pump will handle it Other systems which are in some respects similar to the above are in use, but are not so well known or as extensively used. Hot water under pressure is made use of by numerous manu- facturers for the purposes of drying, heating, etc. However, it probably will not, in this country at least, replace steam as used for similar purposes. CHAPTER XV Hot-water Heating Appliances WE might, in the broader sense of the words, designate all por- tions of a hot-water system as " heating appliances." We confine our use of the term, however, to cover only those parts or " trim- mings " which tend to finish or render the appearance more comely ; also to those appliances which assist in maintaining a uniform temperature arid which render the care and attention due the ap- paratus less of a burden. The early systems of hot-water heating had a small pipe, of usually 1/2" or %" in size, running from the overflow of the expan- sion tank to the basement. This was called a " tell-tale," and the operator in filling the apparatus would leave the water pressure turned on until the water was heard running from the tell-tale. The Altitude Gauge This crude arrangement has been dispensed with and in its place we now employ the altitude gauge, Fig. 142. This is or- dinarily a spring gauge of the Bourdon type. The gauge has two dials, a black and a red one. The black dial is attached to the mechanism of the gauge and registers the height of the water in the system, by feet. The red dial is stationary and is movable only by hand. After filling the system to the proper height, the same being registered on the gauge, the face of the gauge is re- moved and the red dial moved to the same position as that occu- pied by the black dial, when the face of the gauge is then replaced. As the water in the system evaporates, the black dial will drop away from the red one, indicating to the attendant that the water is low in the system. As the gauge is attached to the apparatus at or near the heater, it is necessary only for the attendant to admit sufficient water to the system to bring the black dial back to 146 HOT-WATER HEATING APPLIANCES 147 the position held by the red one, thus indicating that the system is properly filled. The Hot-water Thermometer The hot-water thermometer used on a hot-water heating ap- paratus is a mercurial thermometer, as shown by Fig. 143. The framework is of iron, or brass, on the face of which is the indi- cator. Attached to the face of the indicator is the glass mercury tube, the lower end of which extends through the center of a small FIG. 142. Altitude gauge. FIG. 143. Hot-water thermometer. brass casting. The lower part of this brass casting forms a cup, and this cup part of the casting is turned down until it is very thin. This renders this portion of it very susceptible to the heat. A standard pipe thread is cut on the outside of the casting, which may then be screwed into an opening in the heater or other portion of the heating apparatus. This leaves the lower and thinner part of the appliance submerged in the water. In order to get a true register of the temperature of the water it is necessary that the lower part of the thermometer containing the bulb of mercury be submerged in the water, as shown by Fig. 144. Unless this is done the thermometer will register falsely. 148 PRACTICAL HEATING AND VENTILATION H. W. Thermometer FIG. 144. Right method of attaching thermometer. We have seen thermometers used where they were screwed into an opening which had been reduced in size by the use of several H. w. Thermometer FIG. 145. Wrong method of attaching thermometer. HOT-WATER HEATING APPLIANCES 149 bushings, with the result that the thermometer did not reach the water in the system. Fig. 145 illustrates this, and under such conditions it is impossible to register the correct temperature. Floor and Ceiling Plates Not a very long time ago we were accustomed to notice cumber- some cast-iron plates surrounding the pipes where they passed through floors or ceilings. They would frequently drop a distance FIG. 146. Brass floor and ceiling plates nickeled. from the ceiling, and sometimes fall entirely to the floor below, be- cause they were insecurely fastened in place. These crude affairs have been replaced by a nickeled plate of spun brass, Fig. 146, or iron, Fig. 147. These plates are made in two parts and so PIG. 147. Cast-iron floor and ceiling plates nickeled. constructed as to be adjustable. They are held to the pipe by springs and this method keeps them firmly in their proper posi- tions. The heating contractor now gives much attention to the fin- ished appearance of his work and this fact, no doubt, has led to the use of better trimmings on heating jobs. 150 PRACTICAL HEATING AND VENTILATION Pressure Appliances Some of the more recent developments in accessories to a hot- water heating apparatus are various appliances for putting the system under a nominal pressure without sealing or closing the vent opening of the expansion tank. There is no element of danger presented by the use of any one of these appliances, as the system remains an open one, but is, however, weighted down in a manner which allows of a nominal pressure under the force caused by the expansion of the water within the apparatus. A considerable saving is made in the first cost of the heating apparatus by using an appliance of this character, as not only may there be a reduction made in the amount of radiation installed, but smaller piping may be used, the same as for a pressure system. The Honeywell system is operated by mercury. This appliance is designated as a " Heat Generator " and is illustrated by Fig. 148. It consists of two pipes, one within the other, the larger pipe termed the " stand pipe," the inner one, the " circulating pipe." The upper end of the stand pipe is screwed into the bot- tom opening of a hollow bulb, termed a " separating chamber," which has also an opening at the top into which the pipe connection to the expansion tank is made. The lower half of the stand pipe is screwed into a bottle-shaped hollow casting, as shown by Fig. 149 (12), terminating in a hol- low cup or " shoe " screwed on the bottom of the pipe. The plug (16,) screwed into the bottom of the bottle makes it tight, except for opening (6) on one side near the top of the casting, into which expansion pipe from heating system is connected. The lower part of the bottle is termed the " mercury chamber," being filled with mercury to the height of the small plug shown, (10), making it approximately 1%" in depth. The principle of the operation of the generator is based on the fact that mercury is thirteen times heavier than water, and the apparatus is really a mercury seal, requiring a pressure of about ten pounds to break the seal and allow the pressure to reach the expansion tank. The various parts of the generator are so arranged as to 'allow the mercury to circulate under pressure and to be separated from the water (by plate 2) when the mercury HOT-WATER HEATING APPLIANCES 151 seal is broken by excess of pressure on the system. As the mer- cury is heavier than the water, it settles again through space 8, as per sketch, into the mercury chamber at the bottom of the gen- erator. The rapidity of the circulation through small piping and re- duced radiation, under a temperature equal to steam at ten pounds FIG. 148. Honeywell heat generator. FIG. 149. Sectional view of Honeywell heat generator. pressure, renders the reduced amount of radiation (10$ reduction) effective for cold weather and the wide range of temperature allows of a mild degree of heat in warmer weather. 152 PRACTICAL HEATING AND VENTILATION When installing this system there are a few points to be con- sidered, viz. : (a) The radiation should be figured as for the regular hot- water system, then a deduction of 10$ made. (b) The heater should remain the full size. (c) In proportioning size of mains, allow 1 sq. in. of area for each 100 sq. ft. to be supplied. (d) Make branches and risers of the same size and take branches from side of main. (e) Take branches for second or third floor risers from side of other branches, not from end of. the branch to first floor. (f) Radiator tappings should be as follows: For first floor up to 25 sq. ft. l/ 2 " ; 25 to 60 sq. ft. %" ; over 60 sq. ft. 1". For second floor up to 30 sq. ft. l/ 2 " ; 30 to 100 sq. ft. %" ; over 100 sq. ft. 1". For third floor up to 50 sq. ft. l/ 2 " ; 50 to 125 sq. ft. %" ; over 125 sq. ft. 1". The length of the pipe which screws down into the mercury chamber and connects it with the oval separating chamber is regu- larly 21 inches, which allows of a pressure of ten pounds upon the apparatus. A feature of the generator is that no mercury will be forced out of it and lost through the overflow pipe during the operation of filling the apparatus from the regular water-service pipes. When the water supply valve is opened the mercury is forced up into the separating chamber and held there until the apparatus is filled with water, or until the supply valve is closed, when it falls into the mercury pot and is ready for service. A detailed description of the operation of the generator may be given as follows : When the fire in the heater has warmed the water in the apparatus sufficiently for it to begin to expand, the pressure is exerted downward upon the mercury in the bowl or chamber, forcing it upward through the circulating tube and the space be- tween it and the stand pipe. As soon as sufficient pressure has ac- cumulated to force the mercury to the top of the stand pipe and the circulating tube, the mercury in the bowl will be lowered un- til its level is at the top of the lower inlet of the circulating tube. HOT-WATER HEATING APPLIANCES 153 The two pipes now stand full of mercury, which, owing to the connection of the two columns at the top of the pipes, begins im- mediately to circulate. Unless the fire in the heater is checked the pressure will continue to increase until the mercury is forced below the inlet of the circulating tube, allowing the water to enter and Expansion Pipe FIG. 150. Phelps heat retainer. pass upward to the tank until the pressure is reduced or removed, the baffle plate in the separating chamber dividing the mercury from the water and preventing it from leaving the generator. Owing to the small size of piping used, it is well to ream the ends of each length or piece of pipe used in the installation of the system and it is well also to test the circulation at as low a tern- 154 PRACTICAL HEATING AND VENTILATION perature as 110 and see that a perfect circulation may be main- tained at this temperature. An appliance quite similar to the Honeywell Generator in the results attained is known as the " Phelps Heat Retainer." How- ever, this has no mercury attachment, but consists of a double-act- ing valve inclosed in a cast-iron box, as illustrated by Fig. 150. A weight rests upon the valve disc that opens toward the expansion tank, so that the pressure on the heating system must lift this weight in order that the water may overflow into the tank. The opposite end of the valve opens into the heating system and as there is no weight upon it, the least condensing of the water in the system, due to a low temperature, w r ill open the valve and allow the water in the expansion tank to feed down into the system, thus preventing a vacuum. The pressure on the system at which the retainer operates is sixteen and one half pounds, allowing of a temperature of 250 degrees before the water can boil. As with other appliances of this kind, a large reduction may be made in the amount of radiation ; also small piping and radia- tor tappings may be used, but the heater capacity should remain unchanged, as it is necessary that this should be of ample size. As a cure for sluggish circulation, due to improper methods of piping on work already installed, or a heating plant with insuffi- cient radiation, it would seem that the use of a " generator " or a " retainer " should remedy the defect. CHAPTER XVI Greenhouse Heating THE earlier methods of heating greenhouses were both crude and unsatisfactory. The improvement over the old forms of green- house heating and greenhouse construction has been such as to result in a complete revolution in building and heating the same. The earliest method of heating a greenhouse, and one which for a time was more or less followed in this country, was the brick furnace and flue. This consisted of a brick combustion chamber, which was fitted with a cast-iron front, and the lower part pro- vided with grate bars and an ash pit. The furnace was built in a pit or cellar at one end of the greenhouse, the brick or tile smoke flue connecting with the furnace, rising at a sharp angle to the floor of the house, where it was continued at a slight rise under the bed in the center of the house to the chimney at the opposite end. The hot air radiated by this flue was sufficient to heat a small greenhouse. There were so many objections to the use of this apparatus, such as the overheating and withering of plants, the killing of flowers by escaping gas through the tile or brickwork, etc., that it was discarded in favor of steam or hot water heat, as soon as the latter methods were generally adopted for green- house heating. The original method of hot-water heating in this country, as applied to greenhouse work, consisted of a cast-iron heater of a type similar to that as shown by Figs. 23 and 24. The piping was of cast iron, about 4" in diameter, with a hub or socket on one end. These were fastened together by using iron filings and other ingredients, making a rust joint. The various lines of pipe had an upward pitch to the far end of the house, where they terminated in a hollow cast-iron post with air openings through the top. These were called expansion tanks, 155 156 PRACTICAL HEATING AND VENTILATION though they might more properly have been called " expansion posts." They not only took care of the increase in the volume of water, when heated, but served at the same time to extract the air from the system. We believe Hitchings & Company were the pio- neers in this class of work in the United States. Greenhouses are of two kinds, viz. : the commercial greenhouses in which are grown flowers and vegetables for profit, and the green- houses or conservatories of the wealthier class and as found also in many of our public parks and botanical gardens. In the heating of the latter the first consideration is the efficiency of the ap- paratus, without reference to the matter of economy in the con- sumption of fuel. On the other hand, with the former class (the commercial houses) both efficiency and economy in fuel are a con- stant study with the owner. The increase in the number of com- mercial greenhouses has been such that at the present time there is scarcely a town of any size which does not have one or more greenhouses, and in the towns adjacent to or within easy com- munication of the larger cities, they may be counted by the dozen. It is, therefore, important that the heating contractor become fa- miliar with the modern methods of greenhouse heating how to es- timate the radiation required and in what manner the piping should be erected and the general conditions surrounding the work. Modern Greenhouse Heating The modern methods of greenhouse heating are by steam or hot water. There is a diversity of opinion among florists and garden- ers as to which system of the two is perferable, some florists of large experience advocating steam, while others of equal expe- rience and standing favor hot water. We are inclined to believe that hot water is best adapted for the use of florists for the fol- lowing reasons. (a) Greater economy in fuel consumption. (b) Uniformity of temperature, hot-water heat being more constant and even. Should the fire for any reason get low, the water continues to circulate for hours. (c) Where hot water is used for heating, the atmosphere in the greenhouse is mild and humid, insuring a healthy growth of the plants and flowers. GREENHOUSE HEATING 157 (d) The hot-water apparatus may be put under pressure, if desired, and thus equal low-pressure steam in intensity and quick- ness of action. There are some groups of houses so situated that a steam- heating apparatus is better adapted for heating than would be a hot-water apparatus or where a hot-water apparatus could not be properly installed ; hence it is well that the heating contractor become conversant with each of the two methods. Estimating Radiation A greenhouse structure offers less resistance to cold and frost than any other type of building, and, therefore, requires not only a greater amount of heat but greater care in its distribution in order to insure an even temperature throughout the house. In order to intelligently estimate we must know what tempera- ture is required for each house, as different plants require different degrees of heat. For instance, carnations require a temperature of from .50 to 55 degrees, roses from 60 to 65 degrees, chrysan- themums from 55 to 60 degrees, and houses for ferns, orchids, palms, etc., or, as they are called by florists, " general purpose houses " require from 55 to 70 degrees. Many florists have be- come growers of mushrooms, and these require a temperature of from 54 to 56 degrees. Exposed surface is alone considered in estimating radiation and there are several methods of figuring. Where houses are al- ready erected and it is possible to measure them, the amount of glass and exposed surface may be easily and quickly figured. Where this is not possible, the following rule will be found fairly accurate. For houses not exceeding three or four feet in height at the eaves and when built in groups with no side glass, find the floor area of the house and add one third for ends and pitch of roof. The result will be the amount of exposed glass surface. Example: a house 16' X 100' no glass on sides. 16 X 100 == 1600 -f- J = 533 1600 + 533 = 2133 sq. ft. of glass. For a house 16' X 100' with a belt of glass 2' high under 158 PRACTICAL HEATING AND VENTILATION eaves: Proceed as before, and to the result of 2133 sq. ft. add the side glass 100 X 2 200 X 2 = 400 + 2133 = 2533 sq. ft. of glass. To determine the amount of radiation necessary, use the fol- lowing table. This table is based on the temperature of a climate similar to that of New York City, where the temperature is sel- dom at or below zero and then for only a short period of time. TABLE XVI Temperature Required. For Steam. For Water. 45 50 55 Divide square feet of glass by tt tt a ft ( 8 7 5 4 60 65 70 ft (t tt C 6 5 " 3% 3 4 It is the custom to build greenhouses in as protected a position as possible and this fact is taken into consideration in formulat- ing the above table. When the houses are in a particularly ex- posed position, to give 70 inside, use the figures " 4 " for steam and " 2% " for hot water as divisors and the same proportionate addition for other temperatures. When estimating for the pressure system (sealed tank) of hot water, use the same divisors as for steam. TABLE XVII Temperature Sq. Ft. of glass and its equivalent proportioned to one sq. ft. of surface in heating pipes or radiator. of Air in House. Temperature of Water in Heating Pipes. 140 160 180 200 40 4.33 5.25 6.66. 7.69 45 3.63 4.65 5.55 6.66 50 3.07 3.92 4.76 5.71 55 2.63 3.39 4.16 5.00 60 2.19 2.89 3.63 4.33 65 1.86 2.53 3.22 3.84 70 1.58 2.19 2.81 3.44 75 1.37 1.92 2.50 3.07 80 1.16 1.63 2.17 2.73 85 .99 1.42 1.92 2.46 GREENHOUSE HEATING 159 For a greenhouse exposed on all sides (not one of a group) it is well to figure all wall surface, sides and ends, and for each five square feet of wall surface add one sq. ft. to the glass surface. The preceding table will assist in determining the proportion- ate amount of glass to heating surface for various temperatures in the greenhouse, the outside temperature being at zero. Methods of Greenhouse Piping There has been much discussion among florists as to the relative merits of various styles of piping for greenhouses and we believe the consensus of opinion to be in favor of what is termed the " over- fed system." By this is meant a running of the flow pipes overhead from one end of the house to the other and bringing back a suffi- cient number of return pipes under the benches or beds to give the necessary amount of heating surface in the house. In arrang- ing for the heating of a greenhouse the boiler pit or cellar should, if possible, be placed at the low end of the house in order better to allow for the proper pitch and drainage of the piping, which in a house of considerable length is often a troublesome matter. If the greenhouse is built on level ground the boiler may be placed at either end and in the event of using one boiler to heat a group of houses, the boiler house and cellar should be centrally located in order to facilitate the arrangement of the piping. There are many advantages to be gained by the use of the overfed system, chief of which is the placing of a share of the heating surface in the most exposed portion of the house, thus tempering a large portion of the cold air which finds entrance through or around the ventilators or through the laps in the glass. In setting the glass in a greenhouse the panes are lapped over each other in much the same manner as shingles, or slate are laid on a roof, and the lap made in laying each pane is in many instances not air tight. Again, in securing an even temperature of the air inf-the house the overhead pipes are of great assistance. We show by Fig. 151 a small hot-water apparatus for heating a single house. The potting shed and cellar for the heater are built against the side of the house at one end. The flow pipe rises from the heater in the most convenient manner to a point well toward the top of the 160 PRACTICAL HEATING AND VENTILATION shed. This is the Mgh point of the system and from this point the connection to the expansion tank is made. The flow is then PW I, 1 '' -VJLVV- -^lA-/ 7 ' IM, <-- / i ( ^ ^ -J:i\ * I w,~^&*:'i;~< taken into and across one end of the greenhouse and supplies two main pipes which are hung overhead on the posts supporting the roof. These have a slight fall to the far end of the house where GREENHOUSE HEATING 161 a drop is made, each flow feeding four return pipes which are hung under the benches. The piping (both flows and returns) have a slight fall from the expansion-tank connection to the connection to main return. Fig. 152 shows a skeleton view of one half of the piping, and illustrates the system very clearly. Valves should be placed on the connections to each group of return pipes; those for hot water may be placed on either the flow or return connection. This will enable the florist to cut out from service any portion of the ap- paratus as desired a very necessary operation in the mild days of the spring and fall months. Down Flow Return Return To Heater FIG. 152. Method of piping for greenhouse. The arrangement of the piping for steam is quite similar to that for hot water, the expansion tank and connections, of course, being omitted. When piping a greenhouse for steam, valves must be placed on both supply and return pipes, the air vents being placed on the return end of each group of return pipes and care must be taken to avoid all trapping of pipes and the forming of air pockets in the system. Should the house be a large one and a number of return pipes be placed in each group it is well to use branch tees (see Fig. 52) on the supply and return end of each group of pipes. Where the side walls of a greenhouse are built high from the ground it is sometimes found advisable to place a portion of the piping on the sides. When a number of houses are built side by side it is an excellent plan to build a potting -shed or inclosed passage along one end of the houses, and the main supply pipe 162 PRACTICAL HEATING AND VENTILATION of the heating apparatus should be run through this shed, branch mains being taken off as frequently as is found necessary. In de- termining the quantity and size of pipes to obtain a certain amount of heating surface, the table of pipe size and capacities given in Chapter VI will be found of great assistance. For the mains running through the center of the house it is not advisable to use pipe larger than 3" in size. As these mains are usually hung on the center posts supporting the roof, the increased weight of the heavy piping might cause damage from breakage or sagging. CHAPTER XVII Vacuum, Vapor and Vacuum Exhaust Heating VACUUM heating is the operation or running of a steam-heat- ing plant at a less pressure than the atmosphere, which at sea level is 14.7 pounds per square inch. On the ordinary steam-heat- ing plant we are accustomed to say, for instance, that we have two, five or ten pounds pressure. By this we mean, pressure above that of the atmosphere, and therefore the true pressure on such a plant would be 16.7, 19.7, or 24.7 pounds as the case might be. To state this matter in another form: water boils at sea level, atmospheric pressure, at 212 degrees Fahr., in an open vessel or in the ordinary steam apparatus with air vents open to the at- mosphere. Supposing we relieve the apparatus from all atmos- pheric pressure the water in it will boil at a temperature of 98 degrees. The word " vacuum " means empty space, or space void of matter. We are accustomed to speak of a bottle or other ves- sel from which the contents have been drawn off as being empty. This is not true, because as fast as the receptacle is emptied of its visible contents an invisible volume of air or atmosphere takes its place. Steam and air being of different densities will not mix. Close tightly the air valve on a radiator when there is no pressure of steam on the apparatus and the result will be that as the steam pressure is increased the air in the radiator will be compressed, making it impossible for the steam to fill all of the radiator. Open the air vent and the radiator will fill with steam as the air is pushed ahead of the steam and exhausted through the air vent opening. Steam is an elastic gas, or properly, is water turned into gas by expansion due to heating it to a temperature above the boiling point. If unconfined, water thus turned into steam is expanded seventeen hundred times. Therefore, reverting again to the radia- tor, after the steam with which it is filled condenses, it occupies 163 164 PRACTICAL HEATING AND VENTILATION but a very small part of the space within the radiator, the remainder of the space again filling with air, which must repeatedly be ex- hausted before the radiator will fill with steam. Vacuum as applied to steam heating means the use of some form of apparatus, such as an exhauster, pump, or other appliance, to keep the radiators and other parts of the heating apparatus free from air, or under a vacuum in order that the water in the system w r ill boil at a low temperature and be converted into steam, which may then flow un- obstructed through all piping and radiators. The flow of steam in a vacuum attains a velocity of 1,550 feet per second. Thus it will be seen how quickly a circulation in a heating system can be established. With an apparatus capable of producing steam at 98 degrees (complete vacuum) to 240 degrees (10 Ibs. atmospheric pressure), there seems no doubt but what any building may be readily and easily heated no matter how quickly weather conditions and the outside temperature may change, and that a minimum degree of economy in fuel consumption may be attained. With a regular system of steam heating the air in apparatus is never entirely removed from radiators and piping, particu- larly from the radiating surface. When the vacuum system is at- tached to an apparatus of this kind all air in every portion of the radiators and piping is exhausted from the system, rendering the heating surface more efficient. Thus old systems are benefited by the addition of the vacuum appliances and even though but a partial vacuum be maintained, the betterment of the job in effi- ciency and the saving of fuel are quickly noticeable. To this may be added other features which make a system of this character particularly desirable, among which may be men- tioned : (a) The low cost of installation, it averaging much less than for hot water, yet retaining all of the various degrees of tempera- ture regulation possible with a hot-water system. (b) Economy in fuel over either steam or hot water. (c) Less radiation required than for hot water, while still re- taining the range of temperature. (d) No danger from frosts or leaks, which frequently occur in a hot-water heating apparatus. VAPOR AND VACUUM EXHAUST HEATING 165 (e) Long runs of piping which very often cause trouble, ow- ing to inability to drain them properly, can with a vacuum system be entirely freed from the water of condensation. Improved Methods of Exhaust Heating In Chapter XII we briefly called the attention of our readers to the advantages of utilizing the exhaust steam from the engine. We now desire to describe several of the more modern methods of applying this exhaust to the heating of a building. To derive the greatest benefit from a steam-heating apparatus, it is neces- sary to keep the system free of air, and this is particularly true when heating with exhaust steam. Air in a greater or less quantity is always present in water used for boiler-feed purposes. As the water in the boiler is gen- erated into steam, all air collects in the various radiators or coils of the heating system and this accumulation of air obstructs the flow of the incoming steam and prevents it from distributing uni- formly over the heating service, with the result that the radiator or coil is never working at its full efficiency. Vacuum heating when originally used was applied to a system of exhaust heating and for some time was employed in no other manner. The original patents w r ere taken out by Mr. N. P. Williams, in 1882. This was followed by the " Webster System " by Warren Webster & Co., the " Paul System," by Andrew G. Paul, and the vacuum system was applied to all classes of steam work. Fig. 153 shows the application of the Webster System on an exhaust steam-heating apparatus. Reference to the same will show the various appliances and connections necessary for a system of this character. " The operation of the Webster System is based upon the flow of steam and condensation from a pressure slightly above into a pressure slightly below that of the atmos- phere or into a partial vacuum." This is the explanation given of the principles of the W r ebster System and is, we think, sufficiently clear to be readily understood. With this system a partial vacuum is maintained only on the return pipes and the system is, therefore, applicable only to two- pipe work. At the return end of each radiator or coil, in the place 166 PRACTICAL HEATING AND VENTILATION agin I VAPOR AND VACUUM EXHAUST HEATING 167 of an ordinary valve there is put a motor valve, as shown by Fig. 154 and Fig. 155. The working of this valve is automatic. It prevents the escape of steam from the radiator or coil and at the same time removes all air and all water of condensation from the same, thus making the entire surface of the radiator or coil effective for heating purposes. The pressure of steam in these radiators or coils is not reduced by the vacuum on the returns. This pres- FIG. 154. Exterior of motor valve. FIG. 153A. Webster motor valve at base of riser. sure is dependent on the volume of steam which can enter through the supply valve. At the base of each riser a motor valve is placed as shown by Fig. 153A. The vacuum on a Webster system is produced by the operation of a pump, which pumps the return water and the vapor (air) out of the system and delivers them into a tank which is open to the atmosphere to allow all vapor to escape. The return water is fed from this tank into a feed-water heater, and from this is delivered to the boiler by a feed pump. When a low-pressure boiler is used the vacuum pump is usually driven by a chain-connected electric motor, and the water and air are delivered to a tank placed suffi- 168 PRACTICAL HEATING AND VENTILATION ciently high above the boiler to feed the water into the same by gravity against the low pressure carried on the boiler. With this system smaller flow and return pipes may be used than for the regular two-pipe system of steam heating, and radia- Pc280 FIG. 155. Cross section of motor valve. tors or heating coils may be placed below the line of the main feed or return pipes and work successfully. The Paul System Mr. Andrew G. Paul in seeking a method of keeping a heating apparatus free from air perfected a system which is known as the " Paul System." This is quite different from the other sys- tems of vacuum heating in that it removes the air only, the water of condensation finding its way to the boiler by gravity. It is thus applicable to either low-pressure or high-pressure steam heating, and to either the one or two pipe system. A special apparatus called an exhauster removes all air from the system before the steam is allowed to enter, the automatic or thermostatic air valves on each unit of radiation closing against the steam immediately all air is exhausted and the steam comes in contact with the air valve. This exhausting apparatus is of two kinds, namely, for high pressure and for low pressure. Fig. 156 shows the high-pressure exhauster. It is operated by a jet of steam, and is the kind of appliance used on a system of exhaust VAPOR AND VACUUM EXHAUST HEATING 169 FIG. 156. Paul system high-pressure exhauster. FIG. 157. Paul system Low-pressure exhauster. 170 PRACTICAL HEATING AND VENTILATION heating. Fig. 157 shows the low-pressure exhauster, which may be operated by water pressure. The return pipes and drips connect into a receiving tank, from which the condensation is pumped back to the boiler. This receiver is a closed tank and on it is placed a thermostatic valve for the removal of all air. KEY TO FIG. 158 A. Boiler B. Feed-water Heater C. Engine D. Exhauster F. Feed Pump G. Reducing-pressure Valve H. Back-pressure Valve I. Exhaust from Engine J. Exhaust from Pump K. Compound Gauge L. Vacuum Gauge M. Gate Valves N. Check Valves O. Live Steam to Pump P. Live Steam to Engine Q. Live Steam to Exhauster R. Cold-water Feed S. Feed to Boiler T. Suction to Pump U. Discharge from Exhauster V. Exhaust to Atmosphere W. Radiators X. Air Valves Y. Returns Z. Drips a. Air Pipes b. Supply Heating Pipes d. Blow-off and Overflow e. Relief Pipe f. Angle Valve h. Water Column i. Radiator Valves KEY TO FIG. 159 A. Boiler T. B. Engine U. C. Feed-water Heater V. D. Aut. Return Tank and Pump W. E. Back-pressure Valve X. G. Live-steam Separator Y. H. Grease Extractor Z. I. Steam Gauge a. J. Compound Gauge b. K. Vacuum Gauge c. L. Exhauster d. M. Safety Valve e. N. Water-relief Valve f. O. Gate Valve g. P. Angle Valve h. Q. Check Valve i. R. Reducing-pressure Valve j. S. By-Pass for Red. -pressure Valve Automatic Air Valve Live Steam to Engine Live Steam to Reducing-pressure V. Live Steam to Pump Live Steam to Exhauster Exhaust from Engine Exhaust to Atmosphere Drip from Exhaust Head Heating Supply Pipe Drip from Heater Drip from Grease Extractor Drip from Exhaust Pipe Feed-water Pipe Discharge from Exhauster Drip from Separator Return Pipe Air Pipe Fig. 158 shows the application of the system on a two-pipe system and Fig. 159 shows a single pipe overhead or down-fed VAPOR AND VACUUM EXHAUST HEATING 171 1 i 172 PRACTICAL HEATING AND VENTILATION YAPOR AND VACUUM EXHAUST HEATING 173 system. In operating, the exhausting apparatus is first put in operation and all air removed from the system. The steam as it is turned on the system finding no air pressure to impede its prog- ress flows naturally and unobstructed into each radiator and coil, when having completely filled them reaches the thermostatic air valve, which closes as the steam touches it. When the steam is turned off and the radiator cooled, the air valve again opens, all air in it is exhausted, thus leaving the radiator in condition to re- ceive the steam again. There is a constant vacuum on the air line below the air valves. After the air has been sucked out of the radiators, however, these valves close. The Van-Auken System In many respects this is similar to the Webster and the Paul systems. An exhausting device known as a " Belvac Thermofier " is used on the return end of each radiator, which works in much the same manner as the Webster Motor Valve. A vacuum pump, receiving tank, together with the usual specialties employed in ex- haust heating, are also used in much the same manner as on the Webster System. In application several styles of piping may be used. For a heating plant with gravity returns a drip tank or receiver is made use of, into which the gravity return discharges. The drops from the var.ious risers discharge to the tank through a trap. The main vacuum return is connected to this tank, which feeds directly to the vacuum pump. Mercury Seal Systems The systems described in the preceding pages are what might be called mechanical systems, that is, they require a pump, ex- hauster, or other device in maintaining a vacuum and removing the condensation from radiators and piping. A system of this kind would scarcely be applicable for heating an ordinary residence, or small-sized building. In order to maintain a vacuum on a heating system it is essen- tial that after having once exhausted or driven the air out of the radiators and piping it be prevented from entering again. It can 174 PRACTICAL HEATING AND VENTILATION be readily comprehended how that any simple method of accom- plishing this would be as productive of results as either one of the larger systems. The success of the larger mechanical heating plants led to much experimenting with the smaller systems. Ow- ing to its density, mercury was brought into use in conducting these experiments, with the result that two systems have been evolved and patented, one by D. F. Morgan, now known as the " K-M-C " system, and the other by Jas. A. Trane, known as the " Mercury Seal " system. Both are similar in principle, employing a mercury device for preventing the air from reentering the system after once having been exhausted. The "K-M-C" System Fig. 160 shows the general arrangement of the piping, boiler connections and special devices of this system. The air is driven from the apparatus by a slight pressure of steam and is prevented from reentering the system by a mercury FIG. 160. " K-M-C " system of vacuum heating. seal. The end of the air line is submerged in mercury to the depth of about one half of an inch. This offers but little resistance in VAPOR AND VACUUM EXHAUST HEATING 175 expelling the air, but effectually prevents it from reentering the system. An accumulating tank is used to prevent any water from entering the mercury seal. Sufficient water is always present in this tank to condense any steam which might enter through the air line. Fig. 161 shows a descriptive cut of the system with the various specialties connected. The damper regulator is a very important part of this ar- rangement ; it effectually controls the fire and prevents overheating. It consists of a drawn copper cylinder with a rubber diaphragm Mercury Seal Accumulating Tank FIG. 161. "K-M-C" system showing attachment of fixtures. at the bottom. The expansion of air in the copper cylinder, when heated, operates the regulator, which may be set to open or close the dampers either above or below atmospheric pressure. A special type of automatic air valve known as a " retarder " is used on the radiators and coils and to which the air lines are connected. The supply end of the radiator is provided with a Packless Diaphragm radiator valve, which prevents air leaks at 176 PRACTICAL HEATING AND VENTILATION the valve, which would destroy the vacuum on the system. The air lines are run in quite the same manner as described for the following system. The Trane System The Trane System, as designed by Jas. A. Trane, is also known as the " Mercury Seal System " from the fact that all air from the system is discharged through a mercury seal or trap which effec- Mercury Seal FIG. 162. Mercury seal Trane system. tually prevents the air from reentering the system through the air valves, after having been expelled by the steam pressure. Each radiator is provided with an automatic air valve quite similar to the Paul air valve, having a union drip connection. An air-line pipe is run around the basement, convenient to the steam main and the air pipe from each radiator is connected into it. This air line terminates at a point near the boiler and drops down, connecting into the top of the device known as a mercury seal. See Fig. 162. VAPOR AND VACUUM EXHAUST HEATING 177 The steam piping may be either one of the regular systems, and there is nothing special in the way of erecting the same, ex- cept to see that all joints are made tight and that the stuffing boxes of all valves are tightly packed. A safety valve which is air tight should be used, the " pop " spring valve being recom- mended. A compound gauge registering vacuum and steam pres- sure should be placed on the system. The mercury seal device shown by Fig. 162 is constructed some- what on the principle of the ordinary mercury barometer, the end of the air pipe dipping into the mercury, which is held in the cup- FIG. 163. The Trane system of vacuum heating. shaped interior of the hollow base of the seal. While forming a seal preventing air from entering the system, the mercury offers very litle resistance to the expulsion of air from the system, a pres- sure of but one half pound being necessary to accomplish this. A general idea of the application of this system is shown by Fig. 163, which illustrates the air lines and mercury seal at- 178 PRACTICAL HEATING AND VENTILATION tached to a one-pipe circuit system. The operation of it is as follows : After starting a fire in the apparatus, a steam pressure of from two to three pounds should be maintained for a short period, in order to drive all air out of the system and determine whether or not it is free from leaks. The draught door of the boiler is then closed and the temperature at the boiler falls. As the steam pres- sure is removed from the radiators, the automatic air valves open and the air endeavors to enter the system, but is prevented by the mercury seal. However, the mercury will be drawn up into the tube above the seal to a height representing the difference between the pressure within the radiator and the atmospheric pressure without, and this height representing inches of vacuum will be registered by the compound gauge. The apparatus may then be operated at a very low tempera- ture and should any air again enter the system it is easily expelled by raising a slight pressure of steam on the system. The Byan System The piping for the Ryan system of vacuum heating is installed the same as for the other styles making use of air pipes. An air trap is used instead of mercury for sealing the system. The main air line connects into a side opening in the trap, which is so located that this opening is 27" or more above the water line of the apparatus. A drip pipe from bottom of the trap con- necting into the return below the water line of the boiler, relieves it of all water carried into it through the air line. At the top of the trap is the opening through which the air is exhausted and an equalizing pipe from boiler is also connected into it at this point. A special automatic air valve is used on each radiator, which closes against the steam and opens again as the radiator cools, permitting the exhausting of all air carried into the radiator by the steam. Fig. 164 shows the application of this system. Vapor Heating The Broomell System is distinctly a vapor system, the tempera- ture never exceeding that of water at the boiling point, namely VAPOR AND VACUUM EXHAUST HEATING 179 degrees. The piping for this system while smaller than used for steam has the appearance of the piping of a two-pipe system, the smaller pipe being the drip through which the air and water of condensation are carried back to the boiler through an apparatus FIG. 164. The Ryan system of vacuum heating. which is described as a " combined receiver, relief apparatus and draught regulator." A few loops of indirect radiation termed a condensing coil are located adjacent to and above this receiver and a connection is made from the top of the receiver to the bottom of the coil. From the top of this coil an air pipe is run into the 180 PRACTICAL HEATING AND VENTILATION chimney. The draught in the chimney exerts a pull on the appa- ratus, causing a partial vacuum on the system, which not only exhausts the air, but at the same time accelerates the flow of vapor through the radiators and coils. The pressure on this system is slightly above that of the atmosphere and is registered in ounces on the receiver. See Fig. 165. This receiver is the real heart of the system, regulating the draughts of the boiler by a ball-float attachment and acting as a separator and equalizer in dividing the FIG. 165. Combined receiver, relief, and draught regulator Broomell system. return water and the air which accumulates in the system, and again acting as a relief from any overpressure at the boiler. It can be so adjusted as a regulator that the draught doors of the boiler will close under the slightest pressure. Hot-water radiators are used with this system. The supply is connected at the top of one end by what is termed a quintuple valve, that is, a valve having four holes or ports through the disc, which engage with similar ports in the bottom or seat of the valve. VAPOR AND VACUUM EXHAUST HEATING 181 Thus it may be entirely closed or opened one, two, three or four ports, thereby fully regulating the amount of heat or vapor de- livered to each radiator. At the bottom of the opposite end of the radiator the return end the air and return pipes are con- FIG. 166. The Broomell system of vapor heating. nected by a specially constructed union elbow, which, while allow- ing all air and water to escape from the radiator, is closed against any pressure on the return line. It is recommended that the same amount of radiation be in- stalled as would be used for hot-water heating. Fig. 166 clearly illustrates the installation of this system. Vacuum-Vapor Systems There are some systems of heating at a pressure below that of the atmosphere, which embody some of the principles of both the vacuum and the vapor systems, and these are aptly called vacuum-vapor heating systems. Representing this style of heating we have the Gorton System and the Vacuum Vapor Company's System. 182 PRACTICAL HEATING AND VENTILATION The Gorton System With the regular system of vacuum heating it is not possible to regulate the heat in any single radiator except by automatic heat control. With the regular vapor system the heat in each in- dividual radiator may be controlled, but it is not possible to attain a temperature on the apparatus of over 212 to 215 ; therefore the radiators must be larger than would be required for steam. The Gorton System is capable of heating under a vacuum or at ten pounds pressure. The method of piping used is practically the two-pipe system. An ordinary or a special type of a radiator valve is used on the FIG. 167. Cross section of Gorton auto- matic drainage valve. FIG. 168. Cross section of Gorton automatic relief valve. supply end of the radiator. The radiators may be built for steam or hot water. On the return end is placed an automatic drainage valve Fig. 167. When the radiator valve is opened the drainage valve opens sufficiently so that all air and the water of condensation pass into the return pipe and down to the automatic relief valve VAPOR AND VACUUM EXHAUST HEATING 183 Fig. 168 where the air is exhausted and the water returns to the boiler. The relief valve is operated by the difference in pressure between the steam and the return mains. It opens to relieve the air just as soon as the air in the return main increases the pres- sure, when, having relieved the system, it will again close. This system has the advantage of a wide range of temperature, the use of steam or hot-water radiators and the ability to control the heat in any one radiator. It has this disadvantage, however, that it is applicable only to two-pipe work. Fig. 169 shows a view of the correct position of the automatic relief valve and the pipe connections at the boiler. The return FIG. 169. Gorton system of vacuum- vapor heating. mains may be connected above the water line, as shown, or they may drop as indicated by dotted lines on Fig. 169 and be con- nected below the water line. The lowest point of return mains should be at least 18" above the water line of the boiler, and the relief pipe should be 4" above the return mains. The automatic relief valve is connected to the relief pipe and to the steam main as shown. The Vacuum-Vapor System The vacuum-vapor method may be applied to almost any style of piping. The special appliances necessary are an air trap, a float valve and an ejector. A condensing radiator is used as shown on Fig. 170. The 184 PRACTICAL HEATING AND VENTILATION I VAPOR AND VACUUM EXHAUST HEATING 185 air lines containing vapor and more or less water are discharged into the condensing radiator by means of an ejector. This ejector is connected directly to the boiler or steam main, from which it receives the necessary force to operate it. The air and water pass through the return outlet of the condensing radiator, the water of condensation returning to the boiler by gravity. The air passes through the air trap and thence to the float or vacuum valve and into the atmosphere. In other respects this system is similar to those already de- scribed. The Dunham Vacno-Vapor System A method of vacuum heating styled " Vacuo-Vapor " has been developed by Mr. C. A. Dunham, which is in some respects both novel and interesting, mainly in that the appliances employed maintain a constant difference in pressure between the steam or flow pipe and the return pipe without any mechanical means. The maintenance of this difference in pressure proves of great assist- ance to the circulation on the regular gravity system of steam heating. Like many of the vacuum systems, air valves on the radiators are dispensed with, the air and return water of condensation being taken to the basement into a small tank hung 18" or more above the regular water line of the boiler. A drip from this tank drops to the return opening of the boiler, the water of condensation re- turning to the boiler through this drip, which has a horizontal check valve on it near to the boiler. The condensation in entering the tank passes through a horizontal check placed on the return near the tank. The air, separated from the water in the tank, passes through a thermostatic and vacuum air valve to the at- mosphere. An air trap, Fig. 170A, is placed on the return end of each radiator, remaining open when cold and closing as soon as the heated vapor or steam reaches it. The closed trap retards the steam until the water of condensation collects in sufficient quantity to operate the trap, when it, together with the accumulated air, passes through the returns to the separating tank; When the system is working above atmospheric pressure, the 186 PRACTICAL HEATING AND VENTILATION accumulated air passes freely through the air trap or thermostatic air valve and the vacuum air valve above the tank, the water con- tinuing to collect in the tank until such an amount has been evapo- rated from the boiler as will lower the water line below the end of the equalizing pipe. This equalizing pipe forms a loop approxi- mately four feet in length connecting the receiving tank with the boiler, the end of the loop entering the boiler through an opening, tapped for the purpose, and extending below the water line. This permits live steam to enter the loop, equalizing the pres- sure between the tank and the boiler, permitting the water to flow \ - ..-.>V^iAJ CC^J FIG. 170A. Air trap Dunham vacuo-vapor system. down into the return pipes and through the check valves into the boiler. This action again raises the water line above the bottom of the loop or equalizing pipe, effectually sealing it. The partial vacuum created by the condensing of the steam in the tank after the discharging process, relieves the pressure against the check valves on the return pipes, allowing the accu- mulated air and water to enter the tank, and relieving the returns of any pressure, as the partial vacuum reaches to the radiators. To obtain the most economical results from a system of this character, the supply valves on the radiators should be opened only enough to admit sufficient steam to properly heat the room, the pressure at the boiler being slightly above that of the atmosphere and not greater than one pound. The fire should be banked at night and the system operated under a vacuum. Fig. 170B shows the application of this system for ordinary low-pressure work. Smaller piping is employed than that used on VAPOR AND VACUUM EXHAUST HEATING 187 a regular steam job. The return connections from all radiators should be l/>" in size, and the supply end of radiators tapped up to 50 sq. ft. %", 50 to 90 sq. ft. 1", 90 to 185 sq. ft. 11/4". A special form of this system is devised for larger jobs, using live or exhaust steam, the regular form of air trap being employed FIG. 170s. Dunham system for low pressure. on all radiators, and an air relief and pump governor or con- troller, which acts as a receiver for all condensation, is placed near the pump and is so connected that the pump may assist the cir- culation by pulling directly on the returns. 188 PRACTICAL HEATING AND VENTILATION The Future of Vacuum Heating But a few years ago (1895) a heating engineer made use of the following expression in discussing the future of the heating business before a trade association : " If you can circulate a system below atmosphere in a large building you can certainly circulate it below atmosphere in a dwelling house. If you can circulate it below, how much below can you circulate it? It is possible that in a few years from now we. will be heating houses not by hot water but by steam below atmospheric pressure, of such a low temperature that it gives all of the advantages of hot water without any of its disadvantages." His prediction is now an accepted fact and vacuum and vapor heating, as we may observe by following up the many ideas and the many systems already before us, have by the use of various devices described on the preceding pages become adaptable to any size of residence or building. CHAPTER XVIII MISCELLANEOUS HEATING The Heating of Swimming Fools THE simplest method of heating an open body of water such as a swimming pool or tank is by hot-water circulation. The heater should be placed sufficiently below the level or surface of the water that a natural circulation may be established between the heater and the tank. Fig. 171 shows an apparatus of this kind. The swimming pool illustrated contains approximately 30,000 gal- lons of water when filled to the normal water level. The size of flow pipe leaving the heater should be 6" and this should supply two 4" feed or flow pipes to the pool. These may be connected to it at points about 18" below the water line, the first pipe entering the pool about midway of its length, the last pipe entering well toward the shallow end. The return pipes should be connected from the deep end of the pool at a point about 6" from the bottom. The direction of the circulation of the water is indicated by the arrows shown on the illustration. The heater must be so set that the return open- ings in it are at least 12" below the bottom of the water in the pool. Fig. 172 is an elevation plan of the same apparatus and shows the relative heights at which the circulation enters and leaves the pool. Some engineers favor the method of having the flow pipes enter at the bottom of the shallow end of the pool and the taking of the returns out of the bottom of the deep end. This is not as good a plan as that which we illustrate by Fig. 171. With an apparatus installed in this manner the cross currents in the circulation thoroughly excite and warm all portions of the pool. 189 190 PRACTICAL HEATING AND VENTILATION In estimating heating capacity for work of this character it is safe to assume that each 100 sq. ft. of heater capacity will warm 1,000 gallons of water from 40 degrees to 90 degrees in from six to eight hours. Thus a 5,000-gallon tank would require a 500-ft. hot-water heater to properly do the work. As the tank capacity MISCELLANEOUS HEATING 191 W//////////////^^^^ PRACTICAL HEATING AND VENTILATION is increased in size the relative size of heater may be somewhat decreased as shown by the following table: TABLE XVIII Capacity of Pool or Tank Gallons. Rated Capacity of Hot-water Heater Sq. Ft. Capacity of Pool or Tank Gallons. Rated Capacity of Hot- water Heater Sq. Ft. 5,000 500 40,000 3,450 10,000 950 45,000 3,800 15,000 1,350 50,000 4,200 20,000 1,800 55,000 4,600 25,000 2,200 60,000 5,000 30,000 2,550 70,000 6,000 35,000 2,950 80,000 6,800 There are many circumstances which would vary the above figures considerably. However, those given are sufficiently accurate for estimating and represent the gross rating of cast-iron hot- water heaters as listed by any one of the reliable manufacturers and whose named ratings may be accepted as correct. It is a frequent occurrence to find that the necessary depth for heater room cannot be procured, owing to low ground, trouble with drainage, etc. In a case of this kind it is necessary to make use of steam for heating the water and an apparatus of this kind is somewhat more complicated than the one for hot water already described. Where the steam is obtained from pure water, the pool may be heated by blowing live steam into the water through an orifice of the nature of an injector. A large circulating pipe is arranged at the deep end of the pool as shown by Fig. 173. At the top connection a reducing tee is used, as shown, in making the injector. This not only heats the water but causes also a circulation through the large pipe in the manner shown. Where it has been correctly used this arrangement has proven to be very successful. In the event of heating a large body of water, say 40,000 gal- lons or more, it is well to use two circulating pipes and injectors and they should each be placed at the deep end of the pool about from 18" to 20" from each corner. The manner of circulation of the water in the pool is shown on the illustration Fig. 173. When making use of the injector method the greater the pres- sure of the steam the more quickly a circulation may be established MISCELLANEOUS HEATING 193 and the water heated. For this work we recommend a boiler on which a pressure of from 30 to 60 pounds may be maintained. The usual practice is to clean and refill a swimming pool about once in each week or ten days, depending somewhat upon the num- .S I her of bathers using it. To keep the water as pure as possible during this period there is generally a small stream of fresh water entering the pool constantly, and the overflow openings of the 194 PRACTICAL HEATING AND VENTILATION pool empty the excess water. Therefore, it will be seen that it is but once in a period ranging from six to ten days that the full volume of water in the pool has to be heated. For this reason the steam-injector principle is the most economical as the excess of boiler power may be put to other uses, such as heating a tank of water for domestic uses or for shower baths. In determining the size of boiler power the conditions of the work must be considered. A safe estimate is one-horse power of boiler capacity for each 2,500 gallons of w T ater. Still another method whereby steam can be employed for heat- ing a pool is shown by Fig. 174. Coils of this nature are placed Steam Supply Return FIG. 174. Heating swimming pool with steam coils. in recesses along the sides and end of the pool, the condensation returning to the boiler room, where it is pumped into the boiler or fed to it by an injector or return trap. Owing to the large amount of condensation in coils when used in this manner, it is well to use a header or branch tee coil and to make the runs as short as possible. Heating Water for Domestic Purposes A class of heating now largely practiced is that of heating water for domestic purposes. In the cities and towns of any con- siderable size we find numbers of flat or apartment buildings and it MISCELLANEOUS HEATING 195 is customary in the better class of these buildings to furnish the various apartments with hot water from a central supply tank located in the basement. Such a tank is called a storage tank. There are two methods of heating the water, first by means of a small hot-water heater, called a tank heater, which is directly con- nected to the tank, and second by means of a steam coil within the tank. Such an apparatus becomes a part of the heating speci- fications and the methods as generally adopted should, therefore, be understood by the heating contractor. Storage tanks are made in two styles, namely, horizontal and vertical. The horizontal tank is usually hung from the first-floor FIG. 175. Domestic hot-water supply horizontal tank. joists by means of wrought-iron straps or hangers, or it may rest on brick piers. The vertical tanks are supported by cast-iron legs provided for the purpose. We have found the latter method to be better, as the weight of a large tank full of water is liable to strain the joists from which it is suspended, unless hung very close to a supporting wall. Fig. 175 illustrates the method of hanging a horizontal tank and making the heater connections, and Fig. 176 shows the method of setting and connecting the vertical tank. In making use of the latter method the tank should stand sufficiently high so that the bottom of it is above the return opening of the tank heater, as the return pipe is connected to opening in the bottom of the tank. 196 PRACTICAL HEATING AND VENTILATION When steam boilers are employed in heating the building or when steam is obtained from a central heating plant the water may be heated by means of a steam coil within the tank, as shown by Fig. 177. Black iron or steel pipe should never be used for this purpose, owing to liability of rust or corrosion. The coil should be made of galvanized iron or copper pipe, the latter being Draw-off Tank Heater FlG. 176. Domestic hot- water supply vertical tank. preferable, and it should be well braced or stayed in order that the expansion and contraction will not loosen it. The tank may also be double connected, that is, directly con- nected to a tank heater for use in the summer months and provided with a coil, and connected to the steam boiler in order that steam may be utilized for heating in cold weather. This method makes a very satisfactory arrangement. In determining the size or capacity of tank required several points should be considered. The ordinary tank capacity provided MISCELLANEOUS HEATING 197 when each apartment has its separate supply from water front in range is thirty gallons. When providing for apartments hav- ing but one set of bathroom fixtures, it will be found that an al- lowance of from twenty to twenty-five-gallon-tank capacity for Hot Water Supply r^~ , "^ S; ^~^^S^\ A\ /S steam f Return Draw-off -JT FIG. 177. Storage tank with steam coil. each apartment will prove sufficient. The tank heater should have a capacity of from 20$ to 25$ greater than that of the tank. The following table shows approximately the sizes of tank and heater necessary for from four to thirty-six apartments. TABLE XIX Number of Apartments. Capacity of Tank. Size of Tank. Heater Capacity Size of Grate. 4 100 gallons 22'xeo* 78 sq. n. 6 120 24."X60" 78 " ' 8 180 30"X60" 113 " ' 10 215 30"X72" 132 " ' 12 250 30"X84" 176 " ' 16 365 36"XS4" 254 " ' 20 430 42"X72" 314 " ' 24 575 42"X96" 380 " ' 36 720 42" XI 20" 452 " Should the tank service be used for other than regular domes- tic purposes, additional capacity must be provided. The manufacturers of storage tanks seldom place coils in them except according to specifications received with the order ; therefore, the heating contractor must specify the length of coil or number 198 PRACTICAL HEATING AND VENTILATION of runs of pipe desired and the size of same. As a basis of what is required the following table will prove useful: TABLE XX Size of Tank. Size of Coil. 100 and 120 gal. 180 " 215 " 250 " 365 " 430 " 575 " 720 gal. 4 V pipes 6 V 6 1M" ' 4 IK" " 6 iy 2 " ' Steam for Cooking and Manufacturing Purposes While the use of steam for cooking, or rather the adaptation of Certain methods for accomplishing this, is in reality no part of a steam fitter's education, we wish in a general w y ay to make men- tion of the subject in this chapter, and at the same time to call attention to the use of steam for manufacturing purposes. No large hotel or restaurant is complete in its equipment with- out a steam carving table and in most of the hotel and restaurant kitchens all vegetables are cooked by steaming. Meats may be cooked or roasted in ovens made for the purpose, and when pre- pared in this manner, meat will be as tender as would be a pot- roast cooked in the usual way over the fire of a kitchen range, and will lose less weight in cooking than when roasted in an oven. Ap- pliances for cooking and baking are marketed by the builders of such apparatus and the steam fitter, as a usual thing, has simply to make certain specified pipe connections to the apparatus. The usages of steam for manufacturing purposes are many and varied in character. Double-bottomed kettles for the use of dyeing establishments, soap making, etc., and for heating glue, paste and numerous other purposes are in common use. For carpet cleaning, feather renovating and drying, in hat manufac- tories and for numerous other manufacturing purposes, steam is employed in a greater or lesser quantity, and the subject would require a volume to illustrate and describe the various fixtures and fittings. It is quite probable that more than two thirds of our manufactories make use of steam for purposes other than the generation of power. CHAPTER XIX Radiator and Pipe Connections IN those chapters of this book having reference to systems or methods of piping for steam or hot-water circulation we have fre- quently made mention of certain styles of radiator and pipe con- nections. We shall in this chapter illustrate and explain the sev- eral modes of radiator connections and show the method of using swing or expansion joints on piping, together with some special forms of pipe connections which are made desirable by conditions of building construction. Steam Radiator Connections Fig. 178 shows the most simple form of connecting a single steam radiator with the main. The illustration shows the branch connection taken from the top of the main with a 90 elbow. A FIG. 178. Simple form steam radiator connection. FIG. 179. Steam radiator connected from riser. 45 elbow at this point would be preferable. The valve should be used on the end of radiator farthest from the riser or branch in order to provide for expansion. When a radiator is connected 199 200 PRACTICAL HEATING AND VENTILATION from a riser on single-pipe steam work the connection should be made as illustrated by Fig. 179. This is known as a " stiff " con- nection and when used in this manner there should be a " double swing " or expansion connection at the base of the riser. In order Double Swing Joint FIG. 180. Double swing connection at bottom of riser. that this form of radiator connection may be thoroughly under- stood we illustrate by Fig. 180 a riser feeding three radiators, all of which are connected with stiff joints. The radiator on the first floor is connected direct from riser with an offset valve ; the radi- ator on the second floor is connected by a stiff joint, as described RADIATOR AND PIPE CONNECTIONS 201 by Fig. 179, and the third-floor radiator is connected by a valve placed directly on the tcp of the riser. Note the double swing or FIG. 181. Radiator connected with expansion joints. expansion joints at the base of the riser. When the riser is con- nected to main by a stiff joint on the branch, all radiators fed by it should be connected by expansion joints as shown by Fig. 181. Hot-Water Radiator Connections The regular form of connecting a single hot-water radiator from main and to the return is illustrated by Fig. 182 and needs no further explanation. When the same branch feeds a riser, as well as the first-floor radiator, the connection should be made as shown by Fig. 183. There is always a tendency for hot water in circu- lation to rise quickly to the highest radiator; hence the connec- tion to upper radiator should be taken from the side of the riser as shown. 202 PRACTICAL HEATING AND VENTILATION FlG. 182. Hot-water radiator connection. FIG. 184. Radiator connection for overhead system. I S - T FLOOR RADIATOR. FIG. 183. Radiator and riser fed from same pipe. FIG. 186. Flow connected at top of radiator. FIG. 185. Connection for overhead system- swing joints. RADIATOR AND PIPE CONNECTIONS 203 Fig. 184 shows one method of connecting to a radiator when the riser is fed from above by the overhead system. But one valve is necessary and this may be placed either on the flow or return connection. In order to make the connection as illustrated the riser must be carried a considerable distance from the wall. We favor the use of a swing connection, as shown by Fig. 185, in order that the riser may be run well against the wall and thus make a better appearance. Some fitters favor the method of connecting the flow into the top of one end of a radiator and the return out of the bottom of op- posite end. There are some cases where this is advisable, but on regular hot-water w r ork it is not necessary. By Fig. 186 we show the manner of making this form of connection. Improper Use of Tees Notwithstanding the fact that in nearly all of the text books on steam and hot-water heating the fitter has been warned against it, and that writers on the subject have repeatedly condemned the practice, some steam fitters will persist in using a tee " bull head," Tee used "Bull Head'i Branch' m Branch' ^-Main FIG. 187. Wrong use of tee. as illustrated by Fig. 187. The friction caused by using a tee in this manner must be apparent even to a person unacquainted with steam or hot-water circulation. This is more noticeable on hot-water circulation than on steam. The proper style of fitting to use is the double elbow, illustrated by Fig. 120, and when em- 204 PRACTICAL HEATING AND VENTILATION ployed to divide a main into two branches the object is accomplished with the least possible amount of friction. Fig. 188 as compared with Fig. 187 clearly illustrates this. Double or "Twin" Ell FIG. 188. Double ell for dividing flow. Methods of Pipe Construction When a steam main is run at a considerable length from the boiler it frequently happens that in order to keep the end of it a sufficient distance above the water line it must be dripped and raised again to keep at the height necessary. When this is essen- tial the connection should be made as shown by Fig. 189. The main Main Aut. Air Valve 1 ^ />- Main/ Drip- FIG. 189. Method of relieving main. should be carried a short distance beyond the point at which the rise is made, and a reducing elbow used in connecting the drip. This elbow should be tapped and fitted with an automatic air valve, RADIATOR AND PIPE CONNECTIONS 205 as shown by the illustration. The use of this method will relieve the main of much friction and eliminates the use of a tee placed bullhead on the end of main at point where drip is made. On circuit work it occasionally happens that the main must be run very low owing to certain wood or iron beams supporting the joists. When it is possible to drip the main and rise again this difficulty may be easily overcome. Frequently, however, the base- ment is put to such use that a drip connection cannot be made ^-" Joists FIG. 190. Method of crossing beam without drip. or will not be permitted. By Fig. 190 we illustrate a simple method of surmounting this difficulty, which we think is self- explanatory. Care should be exercised in the alignment of the main on either side of the beam. Artificial Water Line When it is necessary to run a wet return under a building 1 where the basement or a portion of it is unexcavated, it is some- times essential to create what is known as a " false water line." By this is meant a water line above that of the boiler and it is required in order that the return may be kept full of the water of conden- sation. This will prevent the short-circuiting of steam into the return and thereby cause trouble by retaining the water of con- densation in piping or radiators. There are several methods of doing this. Fig. 191 illustrates a mode quite commonly used, and the piping as arranged works all right, although we are inclined 206 PRACTICAL HEATING AND VENTILATION FIG. 191. Common method of establishing a false water line. to favor the method illustrated by Fig. 192. The equalizing pipe shown, connecting top of loop with the main, prevents any false Main to Heating System^ EqualizingPipe- Return from HeatingSystein,~ Down False Water < Line Vent Valve to Drain System / c ==^ into Wet Return ( Water Line^ in Boiler FIG. 19. Another method of establishing a false water line. register due to unequal pressure, which might be a result from the use of the method as first illustrated. Cross-Connecting Boilers When the boiler or heater capacity of a heating plant is di- vided the boilers or heaters should be so valved and cross-con- nected that either of them may be used independently of the other. RADIATOR AND PIPE CONNECTIONS 207 On work of any considerable size it has been discovered that as a matter of safety and economy this plan is advisable. It in- sures the use of one part of the apparatus in the event of an accident occurring to the other, and it is economical from the fact that in mild weather or with a portio'n of the radiation turned off one boiler is sufficient to furnish the amount of heat desired. There is considerable variance of opinion as to the utility of di- viding the boiler power. Where the boiler capacity is fully large Steam Main~(I TV- Steam Main. FIG. 193. Cross-connecting steam boilers. for the work we believe that a considerable saving may be effected in the consumption of fuel by dividing the boiler power and cross- connecting. The methods or form of pipe connections in accomplishing this are many and varied. When cross-connecting steam boilers it is well to use an equalizing pipe connecting with the return header. The boilers may be connected as shown by Fig. 193 or Fig. 194. In the former style of connection angle valves are used on steam supply, while in the latter case a globe valve is placed on the vertical pipe leading from each boiler. The re- turns may be connected as shown on Fig. 194, or as shown on Fig. 195. When cross-connecting two heaters for hot water, globe or angle valves should not be used owing to the obstruction offered 208 PRACTICAL HEATING AND VENTILATION by them to the free flow of the water. Gate valves are the proper style on both flow and return connections. Fig. 196 shows a FIG. 194. Another method of cross-connecting steam boilers. good method of connecting the flow pipes, while that illustrated by Fig. 197 is an excellent method of connecting the returns. Steam or Sediment Cock FIG. 195. Return pipe cross connected. Should there be several flow openings from each heater they should all be connected into a main header from which the supply pipes for the building are taken. RADIATOR AND PIPE CONNECTIONS 209 When cross-connecting two steam boilers of unequal size or height, care must be taken to place them in such relative positions ) C : : i - t ts t\ /f 1\ FIG. 196. Cross-connecting hot-water boilers. that the normal water line of one is on a level with that of the other boiler. It may be found necessary to set the larger boiler Boiler Return Draw-off Connection Boiler Return Water Connection FIG. 197. Cross-connecting returns hot-water boilers. in a pit or to place the smaller one upon a brick foundation, in order to level the water lines. 210 PRACTICAL HEATING AND VENTILATION Pipe Measurements for 45-Degree and Other Angles The base of the triangle being given the length of the hy- pothenuse may be determined by the use of constant multipliers FIG. 198. Measuring 45 angles. for each different angle. Fig. 198 illustrates the method. The following constants are the multipliers. TABLE XXI Angle (line B). Constants (Multipliers). 11M 1.0196 22V 1.0824 30 1 . 1547 45 1.4143 60 2.0000 RULE. To determine the dimension C (the hypothenuse), center to center measure, multiply the distance A by the constant opposite the angle B. CHAPTER XX VENTILATION Importance of Ventilation THE need or importance of ventilation has been recognized for many years. Probably the first effort to ventilate a room of any considerable size was made by Dr. J. F. Desaguliers, as briefly referred to in the introductory pages of this book, who in 1723 arranged a ventilating apparatus for the British House of Com- mons. This apparatus was used for upward of eighty years, being replaced early in the nineteenth century by a system of fans propelled by hand. These fans were arranged to exhaust the foul air at the top of the building. Records of ventilation by means of bellows or blowers by the Romans and later by the Germans are to be had. Without doubt, however, the British attempt marked the beginning of ventila- tion as we to-day understand and use the term. The early at- tempts at ventilation were to remove the air vitiated by the exhalations of many people occupying a single room and by the candles or various styles of lamps used for lighting. With the advent of the present-day type of heating apparatus came the greater need of ventilation in order not only to exhaust the foul air but also to provide a supply of fresh air to replace that vitiated by the breath of the persons occupying a building and also the oxygen consumed by lamps or gas burners for illumina- tion. Oxygen is the all-important element or quality of the atmos- phere and without it we can have neither heat nor light. It is required in the chemical process of combustion and without it fuel will not burn. It is necessary to sustain life and without its presence all living beings would die. The atmosphere we breathe is composed principally of about one part oxygen to four parts of nitrogen, together with more or less vapor or water in a gaseous 211 PRACTICAL HEATING AND VENTILATION state or held in suspension and is expressed by the term humidity. Oxygen is the life-sustaining quality of the air, which is diffused or diluted by the nitrogen. The percentage of watery vapor present varies with the temperature and the exposure or proximitv to a body of water. There is also present in the atmosphere carbon dioxide or car- bonic-acid gas, which by itself is not particularly harmful. Under certain conditions, however, it is detrimental to health, not from the amount usually present in the air, which ranges but from two to four parts in 10,000, but when present in larger quantities due to the exhalations from the lungs of several persons con- gregated in a single room. It then produces a feeling of close- ness or stuffiness, causing headaches and is otherwise detrimental to health. The poisonous matter thrown into the air or given off by our bodies is also the source of great danger to health. For example, confine a person in a tight inclosure. That person will liv.e as long as there is oxygen to breathe, depending upon the size of the inclosure. The oxygen will eventually be con- sumed and the person choke or suffocate, being poisoned by the carbonic-acid gas and impurities exhaled from his own body. If our exhalations are poisonous to ourselves what then may be said of the risk entailed by living in or even temporarily occupying crowded rooms, such as offices, workrooms, or places of amuse- ment where we are breathing the foul air exhaled from the lungs of our neighbors, some of whom may be suffering from tubercu- losis or other diseases and so contaminate the air with the germs of such diseases. Not a very pleasant thought but true never- theless and the fact should be carefully considered by every think- ing person. Ventilation is not a luxury it is a necessity. As another example, enter a residence temporarily occupied for a social gathering. Entering the building from outside where the air is pure into brilliantly lighted rooms not sufficiently ven- tilated and possibly more or less crowded with people, a feeling of closeness, stuffiness, or suffocation is at once apparent. A person not strongly constituted or in good health may in a short time faint from lack of air, while a stronger individual may perhaps become acclimated and soon fail to notice the oppress- ing effects of the foul atmosphere of the room. VENTILATION The use of electricity for lighting purposes has done much toward maintaining the purity of the atmosphere under conditions as cited above. Dr. Tidy after exhaustive tests compiled the following table showing the air consumed by various modes of artificial lighting and the percentage of carbonic-acid gas given off by the various burners : TABLE XXII Light Producing Material equal to 12 Standard Candles. Cubic Feet of Oxygen Consumed. Cubic Feet of Air Consumed. Cubic Feet of Carbonic Acid given off. Cubic Feet of Air Vitiated. Heat, Equal Parts of, raised to 10 Fahr. Common Gas Sperm Oil 5.45 4.75 17.25 23 75 3.21 3.33 345.25 356 75 278.6 233 5 Paraffin 6.81 34.05 4.50 484.05 361 9 Sperm Candles Wax Candles Electric Light 7.51 8.41 None 37.85 42.05 None 5.77 5.90 None 614.85 632.25 None 351.7 383.1 13.8 That the need of ventilation has long been recognized by physicians, scientists and engineers is shown by the works of such men as Chas. Hood, London, whose writings and book published in 1879 are a fair treatise of the subject. Other works more or less practical were published by Dr. D. B. Reid (1844) and by Chas. Tomlinson (1864). Probably the most authentic Ameri- can work is that from the pen of Dr. John S. Billings, of Wash- ington, D. C., a Surgeon of the United States Navy, whose book on warming and ventilation is accepted as a standard authority. Other publications by Thos. Box, F. Schuman, C.E., Butler, Leeds, and the authorities mentioned in the introduction of this book will repay a careful reading. Air Necessary for Ventilation What amount of air is necessary for ventilation? This ques- tion may be answered by numerous examples. Perfect ventila- tion might be said to be the exhausting of the foul air and the admitting of the fresh air in such quantities that the inhabitants of a room or building would never inhale the same air twice, or, in other words, would breathe air inside the building of the same purity as that on the outside. Such a state, however, is neither PRACTICAL HEATING AND VENTILATION practical nor necessary. With the size and conditions of a build- ing and the probable number of occupants known it is possible to estimate very closely the air supply necessary to maintain a certain standard of purity of the air within the building. Not so many years ago a fresh-air supply of 300 cubic feet per hour per person was considered sufficient. To-day we look upon 30 cubic feet per minute or 1,800 cubic feet per hour per person as being the minimum supply essential. Dr. Billings gives the hourly air supply necessary for certain requirements as follows : TABLE XXIII Hospitals legislative Assembly Halls Barracks, Bedrooms and Workshops Schools and Churches Theaters and Ordinary Halls of Audience 2,000 per Seat Office Rooms 1,800 per Person 1,800 per Person Dining Rooms Cu'oic Feet per Hour. 3,600 per Bed 3,600 per Seat 3,600 per Person 2,400 per Person Q nnn T^OT. Qoot It has been recently stated that within a certain congested district in the City of New York there are 70,000 consumptives. There is no question but that this terrible showing is due to the overcrowded offices, sleeping rooms and workshops, the latter more popularly designated as sweat shops, where the admission of only a very small percentage of air, as per Dr. Billings' schedule, would work wonders in the elimination of disease. The average individual spends one third of his or her life in the bed or sleeping room. Without the necessary amount of fresh air to breathe how much solid rest or physical relaxation may we enjoy? Sleeping rooms should, therefore, be well ven- tilated and this may usually be accomplished by the thorough airing of the sleeping room during the day and the opening of the windows at night. By giving the matter a little thought and attention the bed may be so located that no severe draughts are felt by the occupants. However, to properly ventilate the room it should have its separate pure-air supply, tempered by heating, and a ventilating duct leading from the room to the main ven- tilating stack of the building. VENTILATION 215 Massachusetts was the pioneer among the states to enact laws governing the heating and ventilating of public-school buildings. A fresh-air supply of 30 cubic feet per person per minute is demanded and this commonwealth maintains a Board of Engineers to see that the provisions of the law are fulfilled. The laws are imperative, as the following extracts will show: " 1. The apparatus, with proper management, is to heat all the rooms including the corridors, to 70 Fahr. in any weather" " 2. With the rooms at 70 Fahr. and a difference of not less than 40 Fahr. between the temperature of the outside air and that of the air entering the room at the warm-air inlet, the appa- ratus is to supply at least 30 cubic feet of air per minute for each scholar accommodated." " 3. Such supply of air is to so circulate in the rooms that no uncomfortable draught will be felt, and the difference in tempera- ture between any two points on the breathing plane in the occu- pied portion of a room is not to exceed 3 Fahr." We have italicized such portions of the quotation as will bring them prominently before our readers. Other States have enacted laws quite similar and with the standard as set by Massachusetts as a guide, it is quite an uncommon thing to find at this date a school building of any considerable size which is not provided with some form of a ventilating apparatus in connection with the heat- ing of the building. The result is that, as a rule, our children attending school sit and study in an atmosphere much purer than that within the ma- jority of our own homes. This very desirable condition relating to the ventilation of our public schools is due to two distinct causes. First, the writings of eminent physicians, scientists and heating and ventilating engineers, who having noted the former condition of our schools and other public or semipublic buildings and under- standing what was necessary regarding a pure-air supply, have persistently for years conducted a campaign for pure air. Dis- cussions of the subject by engineering societies, articles in the pub- lic press, books written and published in the interests of better heat- ing and ventilating apparatus all had their weight and all have assisted materially in bringing about the improved conditions. The second cause of the changed conditions may be credited to 216 PRACTICAL HEATING AND VENTILATION those manufacturers of ventilating necessities such as fans, heaters, blowers, etc., who have for several years spread broadcast expen- sive catalogues and much other literature and who maintain a corps of engineers to assist architects and builders in the proper arrangement and equipment of buildings for heating and ventilat- ing. Aside from the monetary considerations and profits accru- ing from such work, there is a satisfaction which all must expe- rience when they are contributing to the health and happiness of thousands of human beings. There is still much to be desired, but with the architects alive to the situation and the public aware of the results possible to be obtained, we shall witness very few school buildings erected without the provision of an adequate heating and ventilating apparatus. All government buildings and practically all theaters and places of amusement now planned and erected are provided with ventilating apparatus and the campaign for the ventilating of shops and factories is well under way. Probably no clearer idea of the air required for ventilation can be had than that given by the B. F. Sturtevant Company, which we reproduce in part. " AMOUNT OF AIR REQUIRED FOR VENTILATION. Under the general conditions of outdoor air, namely, 70 temperature and 70 per cent of complete saturation, an average adult man, when sit- ting at rest as in an audience, makes 16 respirations per minute of 30 cubic inches each, or 480 cubic inches per minute. Under the previously assumed conditions of 70 temperature and 70 per cent humidity, the air thus inhaled will consist of about J oxygen and J nitrogen, together with about 1^- per cent aqueous vapor and j^-g- of a per cent carbonic acid. By the process of respiration the air will, when exhaled, be found to have lost about J of its oxygen by the formation of carbonic acid, which will have increased about one hundredfold, thus forming about 4 per cent, while the water vapor will form about 5 per cent of the volume. In addition, the inhaled air will have been warmed from 70 to 90, and, notwith- standing the increased proportion of carbonic acid which is about one and one half times heavier than air will, owing to the increase of temperature and the levity of the water vapor, be about 3 per VENTILATION cent lighter than when inhaled. Thus it will be seen that this vitiated air will not fall to the ground, as has often been presumed, but will naturally rise above the level of the breathing line, and the carbonic acid will immediately diffuse itself into the surrounding air. In addition to the carbonic acid exhaled in the process of res- piration, a small amount is given off by the skin. Furthermore, l 1 /^ to 2% Ibs. of water are evaporated daily from the surface of the skin of a person in still life. If the air supply at 70 is as- sumed to have a humidity of 70 per cent and to be saturated when it leaves the body at a higher temperature, then at least four cubic feet of air per minute will be required to carry away this vapor. " Taking into consideration these various factors, it becomes evident that at least 4% cubic feet of fresh air will be required per minute for respiration and for the absorption of moisture and dilution of carbonic-acid gas from the skin. This, however, is only on the assumption that any given quantity of air having ful- filled its office, is immediately removed without contamination of the surrounding atmosphere; but this condition is impossible, for the spent air from the lungs, containing about 400 parts of car- bonic-acid gas in 10,000, is immediately diffused in the atmos- phere. The carbonic-acid gas does not fall to the floor as a separate gas, but is intimately mixed with the air and equally distributed throughout the apartment. " It must then be evident that ventilation is in effect but a process of dilution and that when the vitiation of the air discharged from the lungs is known and the degree of vitiation to be main- tained in the apartments is decided, the necessary constant supply of fresh air to maintain this standard may be very easily deter- mined. For the purpose of calculation, 0.6 cubic foot per hour is accepted as the average production of carbonic acid by an adult at rest and the proportion of this gas in the external air as 4 parts in 10,000. If, therefore, the degree of vitiation of the occupied room be maintained at, say, 6 parts in 10,000, there will be per- missible an increment of only 2 parts in 10,000 above that of the normal atmosphere, or 2-10,000 = .0002 of a cubic foot of car- bonic acid in each cubic foot of air. The 0.6 cubic foot of car- bonic acid produced per hour by a single individual will, therefore, 218 PRACTICAL HEATING AND VENTILATION require for its dilution to this degree 0.6 -r- .0002 = 3,000 cubic feet of air per hour. Upon this basis the following table has been calculated : TABLE XXIV CUBIC FEET OF AIR CONTAINING FOUR PARTS OF CARBONIC ACID IN TEN THOUSAND SUPPLIED PER PERSON Per Hour. .. Per Min.... 6,000 100 4,000 66.6 3,000 50 2,400 40 2,000 33.3 1,800 30 1,714 28.6 1,500 25 1,200 20 1,000 16.6 525 9.1 375 6.2 231 3.8 DEGREE OF VITIATION OF THE AIR IN THE ROOM Parts of Car- bonic Acid in 10,000. . 5 5.5 6.5 7 7.33 7.5 8 9 10 15 20 30 " The figures indicate absolute relations under the stated condi- tions, and are generally applicable to the ventilation of schools, churches, halls of audience and the like, where the occupants are reasonably healthy and remain at rest. But the absolute air volume to be supplied cannot be specified with certainty in advance, with- out a thorough knowledge of all the conditions and modifying circumstances in fact, the climate, the construction of the build- ing, the size of the rooms, the number of occupants, their healthful- ness and their activity, together with the time during which the rooms are occupied, all have their direct influences. Under all these considerations, it is readily seen that no standard allowance can be made to suit all circumstances, and results will be satisfac- tory only in so far as the designer understandingly, with the knowl- edge of the various requirements as they have here been given, makes such allowance." Methods of Ventilation A building may be properly ventilated only when adequate provision has been made by the architect and builder of such stacks, flues or ducts as may be necessary for the use of the sys- tem of ventilation to be adopted. There are two general methods of producing ventilation, namely, natural and mechanical. Nat- ural ventilation as expressed and understood is caused by ducts so constructed that the velocity of the outside air or difference VENTILATION 219 in temperatures produces a change of air within a building. This method by itself is quite unsatisfactory, but when assisted by heat- ing surfaces placed within the exhaust flues and warming the en- tering air by passing it over or between the heated surfaces of radiators in a manner commonly styled indirect heating, is pro- ductive of fairly good results. This method is shown by Figs. 96, 97 and 98. These radi- ators are located in the basement of the building and connected to the supply or hot-air register by a galvanized-iron duct, the foul air being exhausted through a ventilating duct which is heated by means of an aspirating coil or other device. The enter- ing air may also be warmed by passing between the surfaces of a direct radiator, the bottom of which rests on or is inclosed in an iron boxing connecting with and receiving air through a duct from outside the building. This air is passed from the boxing upward between the sections of the radiator into the room. An arrangement of this kind is styled a direct-indirect or semidirect radiator. See Fig. 101. By placing gas jets, a pipe coil or small radiator in the ven- tilating flue, the air is expanded, creating an upward current which sucks the foul air from the room into the duct. This sys- tem of ventilating may be so arranged as to be entirely adequate for a small residence or a larger building if sparsely occupied, and may be employed to good advantage for small schools or kindred buildings, although as a usual thing, a school should be provided with a system of mechanical ventilation, of which we shall speak later on. In ventilating the living rooms of a residence a main ventilat- ing shaft should be provided, centrally located, into which foul- air ducts from the various rooms should be connected. In this shaft there should be placed an aspirating coil connected with the house-heating apparatus, steam or hot water, for use during the period when the heating apparatus is operated. For summer use the gas supply should be piped into the shaft and one or more gas burners attached. An opening into the shaft in the basement, fitted with a door, should be provided to gain admit- tance to the gas burners. This is a requirement needed only when the rooms are occupied by an unusual number of persons. Fig. 220 PRACTICAL HEATING AND VENTILATION 199 shows a method of connecting the foul-air duct with the ven- tilating shaft. A register should be set in an inside wall of each living room at a point just above the baseboard and a foul-air duct run as shown by the illustration. Rooms having open fireplaces are easily ventilated in warm weather by gas jets placed within the opening to chimney. The fresh-air supply for a residence may be furnished by indirect or semidirect radiators placed as we have shown by Figs. 96, 97, 98 and 101. When no special provision is made for the admis- sion of pure air to a residence, or where the cost of indirect heat- ing seems to make its use prohibitive, there should be at least one fresh-air inlet. This should be placed in the lower or re- ception hall and as great a volume of air admitted as can be tempered by an indirect radiator placed beneath the floor, the -4 VStack 'Ventilating Shaft Foul Air Outlet' Register" Foul Air Duct between Joists |||| FIG. 199. Connecting foul-air duct to ventilating shaft. size of same depending upon existing conditions. The inlet reg- isters for all ventilation of this character should be placed in the wall at a point about two thirds the height of the ceiling and they should be located at a point opposite to the fireplace, if there be one in the room. See Fig. 200. The importance of chimneys as ventilating shafts is not gen- erally recognized. The open fireplace, when in use, provides a VENTILATION 221 most successful means of exhausting the foul air from a room. A chimney or shaft may be successfully used for ventilation by running a smoke flue constructed of boiler iron through the center of the shaft and surrounding it with ventilating ducts of such number and size as may be necessary to accommodate the rooms to be ventilated. When used in this connection a chimney should Fresh Air Inlet Register 3' from Ceiling FIG. 200. Location of fresh-air inlet. be located in the center of the building and the bottom of the smoke flue should rest on a cast-iron plate supported on a brick or stone foundation, as shown by Fig. 201. The arrangement of ventilating ducts is shown by Fig. 202. These ducts rise to the height of the brickwork of the chimney, on the top of which there should be erected an iron canopy open at the sides. The smoke flue should protrude through the top of the canopy and may have a cowl at the extreme end, if desired. The smoke flue should be anchored to the brick walls by iron clamps, as illustrated by Fig. 203. These anchor clamps should be attached at the line of each floor, at the roof line and at the top of the brick chimney. The smoke flue warms and expands the air in the ventilating ducts, inducing an upward circulation, 222 PRACTICAL HEATING AND VENTILATION which exhausts the foul air from each room and discharges it into the atmosphere under the canopy at the top of the chimney. This method of ventilation, in connection with indirect or semidirect radiators for warming, is quite successful and by slight modifications may be readily adapted for many small build- A. A. Brick Chimney B. B. B, Ventilating Ducts FIG. 202. Ventilating ducts in shaft. Iron Clamp FIG. 203. Iron clamps for support- FIG. 201. Construction of ventilating shaft. ing stack. ings. For residences this method may be employed in place of the ventilating shaft as previously mentioned. The movement of air in the vertical or main vent flues should not be less than 6 feet per second. With an arrangement of the flues as described above, if properly constructed, this velocity, or even a greater, should be easily obtained. Make the register openings of such sizes that the velocity of the air through them will not be more than one half that in the vertical duct, or in other words, not more than 3 feet per VENTILATION second. If this schedule is adhered to, no perceptible draughts will abound or be felt by the occupants of a room. When semi-direct radiators are used for warming the enter- ing air, the dampers may be adjusted to suit the state of the weather. With indirect radiation the registers should equal in size and open area those used for foul air. Definite results as to air volume and velocity may be obtained by properly proportioning the amount of heating surface and the sizes of hot and cold air ducts. This is particularly true in cold weather when the maximum amount of pure air would be supplied to the building. There seems to be no question but that the combination of gravity ventilation and indirect heating is one that gives vary- ing quantities of air dependent on atmospheric conditions. In warmer weather, when the minimum amount of heat is necessary, the resulting temperatures and velocities of the air in the ven- tilating flues are less than in colder weather; consequently the volume of fresh air admitted and the volume of air exhausted are less. With this understanding we should not use the average vol- ume necessary as a basis for estimating, but should so plan the work that the volume of air moved in warmer weather would be adequate for the character of the building in which the appa- ratus is placed. CHAPTER XXI MECHANICAL VENTILATION AND HOT-BLAST HEATING Growth and Improvement THE phenomenal growth of the various systems of hot-blast heating and mechanical ventilation during the past twenty-five years is due largely to the better understanding of those who plan and erect buildings as to the need of a positive system of heating and ventilation. Many excellent works have been pub- lished covering the advantages of this type of apparatus and the application of the various methods employed in performing the work. These books and papers are more or less necessarily tech- nical in character and, therefore, useful principally to experienced engineers and are intelligible only to those who have received the benefit of a higher education. While we may not be able to add to the value of what has already been written on the subject, we hope to so describe and illustrate the various methods employed that the average steam fitter or heating contractor will obtain an intelligent idea of the principles applied and the methods practiced in installing work of this character. Our thanks are due to such representative manufacturers of fans and ventilating apparatus as The Buffalo Forge Company, The B. F. Sturtevant Company, American Blower Company, New York Blower Company and The Massachusetts Fan Com- pany and the engineers employed by them for much valuable assistance and for permission granted to use such tables relating to the movement of air, etc., etc., as appear in the last chapter of this book. Experience has clearly demonstrated that mechanical heating and ventilation should go hand in hand, and in order that the cost of installation and operation may be reduced to a minimum, 224 MECHANICAL VENTILATION 225 they should be considered unitedly, planned for unitedly and in- stalled unitedly. A system of heating and ventilating cannot be perfectly controlled where one part is installed independent of the other and without perfect control the cost of operation must be excessive and the results obtained be intermittent, if not a complete failure. Mechanical systems for heating and ventilating are at this date installed principally in buildings of large size, such as schools, theaters, churches, hospitals, factories, etc., and in com- paratively few residences. This latter condition is due undoubt- edly to the cost, both of apparatus and of maintenance. When as a people we shall have decided that we are willing to pay as much for health and comfort (which result from the breathing of pure, fresh air) as we do for the heating of our homes, then, without question, we shall see mechanical methods of heating and ventilating more generally practiced. Another influence oper- ating against the adoption of methods of mechanical heating and ventilation, which possibly has not been heretofore fully recog- nized, has been the antagonism of the steam-fitting trade in many localities to the approval and acceptance of the blower system. In all likelihood this situation is due to two reasons, namely (1) ignorance of the modes applied and the results obtained, and (2) the question of personal gain arising from the adoption of some one of the old orthodox systems of heating. Methods Employed There are two general methods practiced in supplying a building with heat and fresh air and in exhausting or expelling the foul air. These methods are known as the exhaust and ple- num methods. In arranging the apparatus for an exhaust sys- tem, the fan is placed in the main ventilating shaft or duct and cold or fresh air ducts lead to the heating surfaces supplying each room, as would be the case if indirect radiators were used. The entire heating surface may also be placed within a single chamber (brick or iron) and from this chamber the warm-air supply pipes connect with ducts leading to each room. Again, the heating surface may be direct, that is to say, direct cast-iron radiators PRACTICAL HEATING AND VENTILATION or pipe coils placed under windows or at points where the inward leakage is the greatest. In action the fan produces a partial vacuum within the room. This results in drawing the fresh air from outside the building through the coils or other heating surfaces and from them into the various rooms. At the same time it exhausts the foul air through ducts provided for the purpose, which are connected with the main ventilating shaft. In so far as the heating and ventilating results are concerned, it is possible to thoroughly warm and ventilate a building by this method and there are a great many structures heated in this manner. The objections to this mode are that in operation the partial vacuum created draws all air currents inwardly through the crevices around doors or windows, thus often producing a draught which is dan- gerous to the occupants of the rooms ; also, that it is difficult to control a system of this character, particularly in a change- able climate. Again, the locations of the inlet and outlet regis- ters must be arranged with great care, owing to the direct course of the air from the inlets to the outlets, and often the conditions of the building (particularly if previously erected) are such that the ducts and openings cannot be distributed as desired. For these reasons this system is not now generally used; it has been replaced by the so-called " plenum " method. With the plenum method the heated air is forced into each room under a slight pressure and all leaks of air around doors, windows or other openings are outward and no perceptible draughts are felt or experienced by the occupants of the room. As the slight pressure exerted is from the source of the pure- air supply it is impossible for any obnoxious odors or gases to enter into and contaminate the air of the room. With this sys- tem the supply of heated air, as well as the supply of fresh air, or we might say the quality, quantity and temperature of the air are always under perfect control. There are several adaptations of the plenum system of heat- ing and ventilating. The older method employed is where the cold air is supplied to the fan direct from a cold-air chamber or cold-air duct, the fan driving it through the heater or heating coils into the various warm air ducts supplying the rooms of the MECHANICAL VENTILATION building. The air may be sufficiently heated by these coils, or it may be driven through supplementary heaters located at the base of the hot-air flues and be increasingly heated before de- livery to the room or rooms to be warmed. Separate ducts may be arranged to connect the main hot-air supply with the rising flues, or the heated air from the coil may be discharged under a slight pressure into a plenum chamber with which all supply pipes or warm-air ducts are connected. Heat Losses and Heating Capacity Required The proportion of heat losses depends principally upon the construction of the building, whether of frame, stone or brick, the conditions of exposure, that is to say, whether standing alone in an isolated position or protected from chilling winds by sur- rounding buildings, the number and sizes of windows and the amount of exposed wall surface. Brick buildings lose less heat through walls than buildings constructed of wood or stone and of the three classes, the frame structure is usually less compactly erected and correspondingly harder to heat. The percentage of loss through walls of varying thicknesses has been ascertained with sufficient accuracy for estimating purposes, as has also been the percentage of heat transmission through windows (glass), doors, floors and ceilings. The use to which the building is put largely governs the heating capacity required. A schoolhouse or similar structure, built in the open and having a large proportion of exposed glass and wall surface, and where a certain number of changes of air per hour is desired, or a definite amount of fresh air per hour per person required, is proportionately harder to warm than would be a theater with its small glass exposure and usually well protected walls, to say nothing of the animal heat emanating from a large number of people closely assembled. In the latter type of building the matter of furnishing fresh air to replace that vitiated by the breaths of the individuals within the struc- ture, and exhausting the air so contaminated without producing draughts or dangerous air currents, is a problem not easily solved. Assembly halls, churches, hospitals, factories and other types of buildings present conditions of heat losses and air vitiation which PRACTICAL HEATING AND VENTILATION vary according to the diversified uses to which each building is put ; therefore each type of building must be considered separately in planning the heating and ventilating of it. The heating capacity of the apparatus is therefore based on two conditions, namely, the temperature of the air necessary to warm the building and the volume of fresh air necessary to be supplied in order to maintain a given standard of purity of the atmosphere within the building. Reference to the table " Volume of Air Necessary to Maintain a Standard of Purity " given in the last chapter of this book will show the volume of air essential under certain stated conditions. duality of the Air Supplied When a blower apparatus is placed in a building erected in a location where the purity of the air is unquestioned, it may be supplied in its natural state to the building. As a matter of fact, the large proportion of buildings heated and ventilated by mechanical methods are located in the cities, in congested dis- tricts, or in factory towns where the atmosphere surrounding the structure is contaminated by dust and soot and which, aside from the possibility of being more or less filled with the germs of dis- ease, is unfit to breathe. Again, in all buildings heated by arti- ficial means, the air is deficient in moisture, the dryness being so apparent that it is necessary to heat the rooms to a temperature much higher than would be required were proper attention given to the quality of the air supplied. Proper provision for a desirable degree of moisture in the air supplied to a building is as necessary, indeed we may say, more necessary, for health of its occupants, than the heating of it. Proper protection in the way of clothing will prevent chill- ing in a structure insufficiently warmed, but there is no individual resource whereby a person may prevent the oppressive feeling resulting from the dryness or overheating of a room, causing the evaporation of the moisture from the body to such an extent as to produce irritation of the skin and other unpleasant sensations. One can never feel as comfortable inside a room heated to 70 as in the open and balmy outside air when the temperature is at 70. This fact alone shows conclusively that the nearer we MECHANICAL VENTILATION 229 can come to maintaining a fixed standard of humidity within a building, the richer will be the conditions of health and comfort. With these circumstances provided for it is possible at times to breathe better air within than without an edifice, because the weight of moisture in the outside air is variable, as it de- pends upon the conditions of humidity and temperature and these change daily, often hourly. Prof. Kinealy states that the weight of moisture brought into a room per hour by air which enters from the outside, is equal to the number of cubic feet of air, measured at the outside temperature, which enters per hour, mul- tiplied by the weight in grains of the moisture in one cubic foot of air, and that the amount of moisture in one cubic foot of external air is obtained by multiplying its humidity by the weight of moisture required to saturate it at the outside temperature. Again, the same authority states that as it is customary in this country to keep the air of the rooms at 70, and to assume that the volume of the air supplied for ventilation is measured at 70, the following table has been calculated to show the weight of moisture in one cubic foot of air at 70, when the air is taken in a saturated condition at different outside temperatures and heated to 70. TABLE XXV Temperature of Saturated Outside Air. Weight of Vapor in One Cubic Foot of Air when Temperature is Raised to 70 Degrees. Humidity of Air when Heated to 70 Degrees. 0.68 8.5 10 0.98 12.3 20 1.43 17.9 30 2.04 25.5 40 2.92 36.5 50 4.13 51.6 60 5.76 72.0 An Ideal System The ideal system of mechanical heating and ventilation must, therefore, be the system which will not only properly warm a building, but which will at the same time expel the foul air in such quantities as to thoroughly remove all excess carbonic-acid 230 PRACTICAL HEATING AND VENTILATION gas and all poisons of respiration from the atmosphere within the building and replace the air expelled with air which has been washed of its soot, dirt and germs and moistened to such a degree as will insure healthfulness and comfort to the occupants. Fur- ther, the ideal system is one which is always under perfect con- trol, giving certain definite results within a minimum cost of maintenance. Our readers may ask if all this is possible, to which we reply : Yes, not only possible, but further, that systems of this character are now in constant use. Installations of this kind are known as the " double-duct system " or more familiarly as the " hot and cold system." The reason for these appellations is shown in the following descriptions of apparatus. Taking the modern school or public building for illustration, Fig. 204 shows a system of this kind as designed by the Buffalo Forge Company. The fan, heaters and air ducts are arranged in the usual manner. The tempering coils are located nearest to the fresh-air inlet and are of sufficient capacity to maintain any temperature desired up to 70 or 80. The coils are spe- cially constructed to admit of temperature regulation by hand, or the temperature in the spray or humidifying chamber may be automatically controlled by means of a by-pass damper under tempering coils. At one end of the spray chamber are located the spray nozzles. These are made of brass and are of simple construction, practically atomizing the water and distributing it uniformly throughout the chamber, the discharge being par- allel to the air currents. At the opposite end of the chamber is located the eliminator or separator, which removes all free par- ticles of moisture from the air before it enters the fan which draws the air direct from the humidifying chamber through the eliminator. The air thus cleansed and moistened is then dis- charged through the coils of the heater into the plenum chamber from which the various ducts supplying the building are taken. Reference to Fig. 205 (which is an elevation plan of an appa- ratus designed for the Carnegie Library at St. Louis, Mo.) will show that the entire volume of air from the fan may be delivered through the heater, or a portion of it may be passed around the heater through the by-pass shown and mixed with the hot air in such quantities as desired or necessary to maintain a given MECHANICAL VENTILATION PRACTICAL HEATING AND VENTILATION MECHANICAL VENTILATION 233 temperature within the building. Thermostatic control at the mixing dampers for each room is an essential and special feature for a system of this character. It may be well to state that the water for the sprays may be furnished from city pressure. The most economical method, however, is to use the water continuously until it is unfit for further use. This is achieved by draining the water separated from the air by the eliminator into a well, from which it is FIG. 206. Wire screen for cleansing air. pumped by a centrifugal pump and delivered again to the spray system. This pump may be direct connected or driven by belt from the fan, or a separate motor. Air cleansing and humidifying may be secured by several methods. For cleaning it of soot and dust, the air may be passed through a fine wire screen similar to that shown by Fig. 206. Originally cheese cloth stretched over wooden , frames was used. These frames were made removable, to be replaced when clogged with dirt. PRACTICAL HEATING AND VENTILATION Coke washing and purifying seems to be a very good method of removing dust and dirt and at the same time moistening the The coke is placed on shelving within a wire cage, through air. a i which the air is passed on its way to the fan. At the top of the cage the water supply is placed. The water is allowed to trickle down over and through the coke, while the air passing through MECHANICAL VENTILATION 235 2S6 PRACTICAL HEATING AND VENTILATION at right angles is purified and moistened. Fig. 207 shows a per- spective section of a school with heater, fan, coke washer, etc., as installed by the American Blower Company. The fresh air enters -a the building in the usual manner, through a screened opening in basement wall, passes through tempering coils, or direct through by-pass under the coils, to the coke washer and from here to the fan. MECHANICAL VENTILATION 237 It is delivered to the heater or passed around it in the usual manner and under thermostatic control is admitted to the vari- ous rooms through ducts leading out of the plenum chamber. Quite similar is the apparatus of the New York Blower Com- pany, as illustrated by Fig. 208. As conditions of area, location, etc., largely govern the char- acter of the apparatus installed, each particular building must be separately considered and this fact is responsible in no small degree for the many arrangements and designs of the blower system. One of the many Sturtevant methods is shown by illustration Fig. 209. It is a three-quarter housing pulley fan with blow- through heater for the " hot-and-cold " or " double-duct " sys- tem. An apparatus of this kind is used on work where space is limited, or where the space allotted is in such form as to preclude the placing of apparatus of the ordinary form with moistening chamber and tempering coils. The outlet from the heater may be made to discharge directly outward from the end, or upward or downward in either direction. In fact, the methods of setting and housing of the fan, whether a steam fan or operated by a pulley, are such as may be adapted for any special form of installation. A typical apparatus for heating and ventilating a school is shown by the small basement plan Fig. 210. In this case the fan discharges in opposite directions through separate heaters to the right and to the left into separate plenum chambers, as shown. This arrangement of the apparatus is particularly com- mendable owing to the centralizing of the fan and heaters and the direct delivery of the warm air. One engineer summarizes the features of this system as follows: " The entire heating surface is centrally located, inclosed within a fireproof casing, and placed under the control of a single individual, thereby avoiding the possibility of damage by leakage or freezing incident to a scattered system of steam piping and radiators. The heater itself is adapted for the use of either exhaust or live steam, and provision is made ^for utilizing the exhaust of the fan engine, thereby reducing the cost of operation (of the fan) to practically nothing. At all times ample and 238 PRACTICAL HEATING AND VENTILATION positive ventilation may be provided with air tempered to the desired degree. Absolute control may be had over the quality and quantity of air supplied. It may be filtered, cleansed, heated FIG. 210. A typical method for schools. or cooled, dried or moistened at will. By means of the hot and cold system, the temperature of the air admitted to any given apartment may be instantly and radically changed without the employment of supplementary heating surface." Fans for Blowing and Exhausting For exhaust ventilation and the removal of smoke, obnoxious gases, etc., from factories or other buildings, the regular forms of fan wheels used are of the disc or the cone type. Fans of this character are lightly constructed, are easily installed and require but little power to operate when run at low speed. The Cone type of peripheral discharge, without any casing MECHANICAL VENTILATION 239 whatever, is thought to give the highest efficiency. They are said to produce better results in volume of air moved than could be secured by the use of the ordinary type of disc fan with straight blades. The fan may be driven by a direct-connected motor, as shown by Fig. 211, or may be pulley driven, as shown by Fig. 212. These illustrations also show the manner of setting or installa- tion. This type of fan is frequently used in the main vent shaft of a church, school or similar building in place of an aspirating coil where " assisted ventilation " is necessary. The centrifugal fan wheel illustrated by Fig. 213 is the type of steel-plate fan as used in all blowers whether the housings are made of steel, brick or wood. There are several adaptations of this type of steel-plate fan, which space will not allow us to illustrate or describe. The blades may be curved or they may be bent backward to avoid noise. Various manufacturers have vary- ing ideas of efficiency and forms of construction. The fans illus- trated may be considered as representative of the several types. The propeller or disc fan, as the name implies, .propels the air forward by impact and centrifugal force and is efficient for moving large bodies of air under slight resistance. For driving air through heaters and long pipes or ducts, or delivering a fixed volume of air in a stated period or under great resistance, the type of fan wheel illustrated by Fig. 213 is now almost universally employed. Types of Heaters There are several types of heaters as used for mechanical or hot-blast heating and ventilation. The form of the heater em- ployed depends largely upon the character of work to be per- formed and the space to be occupied for its installation. Different requirements demand different heaters and it would be hard to select one make or type of a heater which could always be adopted. Again, the size and shape of the heater depend upon the extent or number of degrees the air is to be heated, the volume of air passed by the fan and the steam pressure available. As a rule, the heater installed for this class of work takes the form of what might be designated as a " set " or " group " of steam coils made from 240 PRACTICAL HEATING AND VENTILATION FIG. 211. Ventilating fan with direct- connected motor. FIG. 213. Type of steel plate fan. FIG. 212. Pulley-driven ventilating fan. MECHANICAL VENTILATION 241 wrought-iron pipe, usually 1" in diameter and screwed into cast- iron bases of various forms, composing sections^ the sections being then assembled in groups of two or more, according to the needs of the work. The Sturtevant mitre type of heater is illustrated by Fig. 214. Steam is admitted at the top of the inlet header or section and the condensation removed at the end of the outlet section, each of the sections having an independent feed and drip. The regular Sturtevant type of heater and the construction of the base are shown by Fig. 215. In this type of heater (made FIG. 214. Sturtevant mitre type of heater. also of 1" pipe) the pipes are set 2%" on centers, providing a free area for passage of air equal to about 40^ of the full area of the face of the section. The arrangement of the interior of the cast-iron base and the division partition or diaphragm are clearly shown by the illustration. The steam enters the upper part of the base and feeds one end of the various pipe loops, pass- ing upward and across the top and down the opposite side of the loop, the condensation entering the lower division of each header, from which it passes to the return drip. The headers or bases are made to accommodate either two or four rows of pipe, and the compactness of the heating surface is shown by the fact that within a space of 6 feet in length, 7 feet in 242 PRACTICAL HEATING AND VENTILATION height, and 7% inches deep, nearly 1,000 lineal feet of pipe may be massed. The Buffalo Manifold Heater is illustrated by Figs. 216 and FIG. 215. Sturtevant heater and base. 217, and the Mitre Coil Heater by Figs. 218 and 219. The Buf- falo Manifold Heater is particularly efficient due to the peculiar form of the heater base. FIG. 216. Buffalo heater showing FIG. 217. Buffalo heater showing connections. base. The heaters of the American Blower Company and of the New York Blower Company take the usual form in construction, but MECHANICAL VENTILATION 243 differ in the arrangement of the heater bases. The A. B. C. heater base is divided lengthwise by a diaphragm, the flow entering from one side of the partition, the return passing through the chamber on the opposite side of the partition. The form of the New York heater base is shown by illustration Fig. 220, which also shows this particular heater with a part of the casing removed. Fig. 221 shows the A. B. C. Heater complete ready for the casing. The regular form of cast-iron indirect sections may be used in connection with the blower system for heating and ventilating schools, churches or buildings where it is not necessary to heat the FIG. 218. Buffalo mitre type FIG. 219. Assembling of mitre of heater. type of heater. air to a very high temperature. A hot-air chamber is provided in the basement and the indirect sections assembled into stacks and arranged in two, three, four or more tiers, as occasion demands. Each tier is supported on I beams or railroad rails. There are also special forms of cast-iron sections available for use with a blower apparatus. The fact of so large a heating surface being contained within a comparatively small space, as with any one of the heaters men- tioned and illustrated, and the further truth that but one fifth of the surface ordinarily required for direct heating is necessary for the hot-blast system, are points of economy worthy of serious con- sideration. To these advantages we may add efficiency of service, 244 PRACTICAL HEATING AND VENTILATION as it is conceded that, owing to the rapid movement of the air over the heating surfaces, they become three times more efficient than heating surfaces in comparatively still air, as in the case of direct radiation. FIG. 220. New York heater showing construction of base. One point in heater construction we wish to make plain. The heater may be so valved and connected that certain sections may be used for live steam, certain sections for exhaust steam from an engine-driven fan or other source, or all of the sections may be used for live or exhaust steam as the case may demand. Methods of Driving Fans The method of driving fans for ventilating or for a combined system of heating and ventilation includes a detail of construction MECHANICAL VENTILATION 245 unnecessary to discuss at length. In so far as efficiency is con- cerned, fans of all types may be driven by electricity (a direct connected or independent motor) or by steam. It frequently happens that fans are installed in positions where electric power is available and where it would be inconvenient to use an engine. In such a situation an electric-driven fan with motor directly attached is without doubt the most suitable and economical. Again, when a fan is used to accelerate the movement of air in a ventilating shaft or duct, it is easy to install an electric- FIG. 221. A. B. C. heater ready for casing. driven fan, which may be started, stopped and controlled from a switch located in a convenient position for the attendant's use. The motor used should be independent, that is, should be used for no other purpose than that of driving the fan. An engine-driven fan in an instance of this kind would not be desirable. For an apparatus used for heating and ventilating, such as described in the preceding pages of this book, an engine-driven fan is no doubt the best and most economical. The heater connections are so arranged that the exhaust from 246 PRACTICAL HEATING AND VENTILATION the engine driving the fan may be employed for heating purposes and as this exhaust has probably 95$ of its original value in heat units, the cost of driving the fan is reduced to practically nothing. The requirements for an engine of this kind are lightness of weight and freedom from noise and vibration when run at high speed. FIG. 222. Type of A. B. C. vertical engine. FIG. 223. Showing A. B. C. self- lubricating device. Simplicity and reliability are at all times essential. Fig. 222 shows one of the many types of the A. B. C. engine. It is for low pres- sure and of the vertical type, inclosed to keep the parts free from dust and dirt, and self-oiling or automatic. An interior view showing the mechanism of the self-lubricating system is shown MECHANICAL VENTILATION 247 FIG. 224. The Sturtevant horizontal engine. FIG. 225. The Sturtevant double upright engine. 248 PRACTICAL HEATING AND VENTILATION by Fig. 223. When used in connection with a heating and ven- tilating apparatus, such as would be required for a school or simi- lar building, it is desirable that a pressure of not more than 30 Ibs. be carried ; therefore the engine must be supplied with large cylin- ders in order that the required power may be produced. Fig. 224 shows a horizontal engine of this kind. When located where there is more or less dust in the atmosphere an engine of the vertical, inclosed type is more desirable. The double-upright or vertical inclosed engine illustrated by Fig. 225 represents another type of engine specially designed for this class of work. Some Details of Construction The following details of Sturtevant methods are typical of those in use on blower system construction. The planning of a mechanical system of heating and ventila- tion, the determining of the size of each portion of the apparatus FIG. 226. Form of elbow for hot-air FIG. 227. Manner of reduo duct. ing size of air duct. and the ordinary details of construction should be left with an en- gineer whose experience at work of this character qualifies him to handle it accurately and competently. There are some few de- tails of construction with which we should become thoroughly familiar. From illustrations and descriptions given on the preceding MECHANICAL VENTILATION 249 pages we should have a good understanding of the methods of placing the mechanical portion of the apparatus, arrangement of air chambers, moistening apparatus and eliminators. The flues, which should be built in the walls as the construction of the building progresses, should, if possible, be tile-lined. If not tile-lined, they should be plastered smooth. The ducts (the name given to all horizontal air passages) are usually made of galvanized iron, although in many instances it is necessary to run a portion of them underground, in which cases they should be constructed of brick or tiling. Sudden turns or angles in the ducts should be avoided. In making a 90 angle turn, the elbow should FIG. 228. Iron duct construction. be built with as large a sweep as possible. Illustration Fig. 226 shows the proper construction of the elbow. An abrupt reduction in the size of the diameter of the pipe should be avoided ; all unnecessary friction is eliminated by a grad- ual diminution of the pipe size. This is illustrated by Fig. 227> whereby we show the manner in which a small pipe should be taken from a main duct. Fig. 228 shows the method of constructing an iron duct and by Fig. 229 we illustrate the method of constructing a brick duct when it is essential for a portion of the air supply to turn at right angles, the remaining quantity continuing in the. same direction. The movements of air and water are in many respects quite similar. The same methods employed for the elimination of fric- 250 PRACTICAL HEATING AND VENTILATION tion from the pipes conveying water may be used with good re- sults in conducting air. This is very clearly illustrated by the use of a double elbow when it is necessary to divide the supply, send- ing a portion of it in either direction. The proper arrangement of ducts and dampers has much to do with the success or failure of an apparatus of this character. Two ducts, one conveying the hot air, the other conveying the cold air, are run to the base of the flue supplying a room. It is under- stood that each room should have an independent supply. Mixing dampers are placed where the hot air and cold air enter the flue. FIG. 229. Brick duct construction. Fig. 230 shows an arrangement of a damper of this character and the method of operating the damper from within the room. While this mode is extensively used, nevertheless it is open to some objec- tions. The air currents strike squarely against the damper plate, causing considerable friction. The Sturtevant method is commend- able and is clearly illustrated by Fig. 231 and Fig. 232. As the damper is cylindrical in form it allows the air to mix in proper MECHANICAL VENTILATION 251 quantities at the will of the operator and without friction. The dial placed within each room and the chain attachment are shown by Fig. 233. These dampers may be manipulated by a thermostat. This arrangement we will show in a later chapter. The screen or register opening for the entering air should be placed at a point about two thirds the height of the ceiling and FIG. 230. Type of mixing damper. in such a part of the room as will insure the complete distribution of the air. Frequently the proper location may not be utilized, due to the particular construction of the building and it, there- fore, becomes necessary to assist the distribution of the air in cer- tain directions. This is accomplished by means of a diffuser placed 252 PRACTICAL HEATING AND VENTILATION over the face of the register, as shown by Fig. 234. This appli- ance breaks up the volume of air admitted, deflecting it into sep- arate currents and thereby more effectually warming the room. FIG. 231. Stiirtevant mixing damper. FIG. 232. Sturtevant mixing damper showing chain for operating. FIG. 233. Enlarged view of dial and chain. FIG. 234. Diffuser placed over register face. MECHANICAL VENTILATION 253 Factory Heating Before the fan and blower came into general use the problem of satisfactorily heating and ventilating factories of any considerable size, was often a vexatious one and the results as often obtained were far from being efficient or desirable. The use of fans for exhausting the foul air, smoke or gases incident to the manufac- turing of some classes of products, and for forcing the distribution of heated air has revolutionized the methods of factory heating and now definite results and efficiency are assured. The exhaust type of fan as illustrated by Fig. 211 and Fig. 212 may be employed with successful results in the removal of foul air and gases and for heating a blower fan and pipe heater arranged for use of all available exhaust steam may be utilized. Probably the most simple and the easiest type of factory build- ing to heat and ventilate is the one-story building. They are usu- ally sparsely occupied and the amount of floor space devoted to the use of each employe is considerably larger than the space per capita in offices or public buildings ; therefore, the ordinary ven- tilation of the building is not a difficult matter. On the contrary, with regard to heating, the customary factory structure is well lighted by many windows and not only presents large exposed wall surface to the action of the w r ind and weather, but also from the form cf its construction has a very large loss of heat or leak- age through the roof. In a building wliere the process of manufacturing does not fill the air with poisonous gases, the fan may be supplied with air from w r ithin the building. Therefore, the loss of heat is only that wasted by leakage, the air being turned over and over and heated to the necessary degree of temperature to allow for heat losses through windows, walls and roof. The fan and heater should be centrally located in order that an even distribution of the heat may be secured throughout the building. The air is carried around the building in galvanized pipes and distributed through openings located at intervals in the piping. Fig. 235 shows an adaptation of this method and is the type of an apparatus designed by the Sturtevant Company. When a factory building of more than one story in height is PRACTICAL HEATING AND VENTILATION in process of erection, flues for the distribution of the heated air may be built up through the pilasters and thus not engage any. space within the building. The heated air may be supplied to these flues through a brick underground duct or through an iron duct located in the basement. For certain classes of mills or factories this method is preferable above all others. Where a blower system is installed in an old factory structure, the most simple form of air distribution is by a galvanized iron stand pipe, as shown by Fig. 236. The openings for each floor may be made in the manner shown, or the piping on each floor car- ried to a central point, the distribution there taking place. u FIG. 235. Sturtevant method of factory heating. In one sense the heating of factories in this manner far excels all other methods. The moving belting, shafting and machinery all tend to break up the currents of air and assist in its distribu- tion, and the further fact that the operatives in a large percentage of all factories are on their feet and moving about, are not as susceptible to draughts or air currents as would be the case in a factory where the employes were continually sitting or re- mained inactive. This circumstance renders the location of air outlets and the installation of blower systems a comparatively easy task. The shape and size of the building and the usage to which it is put are factors w r hich largely govern the form of the apparatus and the method of installation. MECHANICAL VENTILATION 255 Relative Cost of Installation and Operation No direct comparison between the cost of installing a fan or blower system and any one of the other methods of heating, viz., FIG. 236. Another form of factory heating. furnaces, steam or hot water, can well be made, as the cost of a blower system increases or decreases according to the rates of air PRACTICAL HEATING AND VENTILATION change demanded, that is, the number of times per hour, the air within each room shall be changed ; in other words, according to the size of the apparatus and not necessarily according to the size of the building. On the contrary, the cost of a direct or indirect system of heating, steam or hot water, without ventilation, increases in proportion to the size of the building and the added cost for ven- tilation may be much or little, corresponding to the amount of ventilation or air changes secured. It has been suggested that as a people we will not tolerate cold rooms, but that we will tolerate a vitiated atmosphere, to which we would add that such toleration on the part of the owners of many buildings is carried to such an extent that the buildings fre- quently are unsanitary and unhealthy, conditions which are reme- died only when pressure is brought to bear upon the owner. It is probable that the cost of installing an indirect system of heat- ing with " assisted " ventilation is in excess of the cost of the blower system when the volume of air moved is considered. The cost of operation, labor of attention required and expense for fuel for the blower system of heating are not very much in excess of the cost of operating other systems. Our public schools, a class of buildings, many of them quite similar in arrangement and design, the rooms averaging 30' X 36' in size and from 12 to 14 feet high, and provided for the use of from fifty to sixty schol- ars, form a very good basis for comparison as to expense of main- tenance (labor and fuel) for the heating and ventilating appara- tus. Carefully preserved records show some interesting data. The cost for mechanical heating and ventilation for a school building of, say, twenty rooms is less per room than for an eight or ten room school. Where furnaces are used there is very little difference in the cost of labor of attendance, or for fuel per room. The records of one city show a comparison of costs, as fol- lows : For five schools provided with a fan and direct and indirect system the cost per room for attendance averaged $62.00 and for fuel $71.00. For six schools provided with a direct and indirect system (assisted ventilation) the cost per room for attendance averaged $61.00 and for fuel $70.00. For twelve schools with fur- nace heat and ventilation the attendance averaged $52.00 per room and the fuel $72.00. For two schools heated with a direct steam MECHANICAL VENTILATION 257 apparatus (no ventilation) the cost of attendance averaged $58.00 per room and fuel $45.00. Upon comparing the figures we find that the fuel bill for heat without ventilation averaged $45.00, or $27.00 per room less than for furnaces with the amount of ventilation they provided ; $25.00 less than for direct and indirect heating and assisted ventilation and $26.00 less than for the fan system of ventilation with direct and indirect heating. Thus the cost of ventilation approximated $25.00, $26.00 or $27.00 per room for fuel, with attendance cost- ing but a very little more than for direct steam and no ventilation, and there seems to be no question but what those schools equipped with a fan were better ventilated than any of the others. Many other comparisons show the expense for fuel with a me- chanical ventilating apparatus to be less than that incurred with furnaces, while the cost of attendance, due to more skillful labor demanded, was approximately one third greater than for the at;- tendance given the furnaces. Another item of interest in the comparison of tests shows that year by year the expense of maintenance for the mechanical sys- tems remained very nearly the same, while the figures furnished for furnaces and other systems vary largely. An average of all records at hand reveals that the actual cost of heating is less for the blower system than for other methods, and that whatever further increase in cost is shown is chargeable to the ventilating portion of the apparatus, this increase being much or little in proportion to the quantity and quality of the air pro- vided for ventilation. Apparatus for Testing Systems of Heating and Ventilation In order to make a test of any mechanical apparatus it is necessary that instruments of absolute and positive accuracy be used in making and recording the test. This is particularly true in testing systems of mechanical heating and ventilation, as re- gards temperature of steam or highly heated air, the velocity and the amount of moisture or humidity in the air under varying conditions. A type of thermometer for conducting a test at high tem- peratures is illustrated by Fig. 237. This consists of a high- 258 PRACTICAL HEATING AND VENTILATION grade thermometer, the tube of which is inclosed in a brass casing. The thread at the bottom is a standard-pipe thread and can be screwed into any ordinary fitting. As shown by the illustration, the bulb extends well down into the opening into which it is FIG. 238. Anemometer. FIG. 237. High-temperature thermometer. screwed in order to insure that the reading on the instrument scale will be accurate. The bulb is protected by a section of thin brass pipe as shown. The movement or velocity of air through ducts or openings may be readily determined by the anemometer, or air meter, as shown by Fig. 238. The indications are obtained by the revo- lution of a series of fans, acting first on a long hand, capable of recording the low velocity of fifty feet per minute on a large dial divided to 100 feet, and then successively by a train of wheels, on the indices of five smaller dials, each divided into ten parts, and recording respectively 1,000, 10,000, 100,000 and MECHANICAL VENTILATION 259 10,000,000 feet or 1,894 miles, an amount found to be more than adequate to the most protracted observations. A disconnection is provided on the rim of the instrument, which sets the recording hands in or out of gear without influencing the uniform rotation of the fans. The velocity recorded by the anemometer multiplied FIG. 239. Wet-bulb hygrometer. by the area of the air pipe or orifice through which the air is moving will give the total volume of air passing. An instrument for noting the percentage of saturation of the air (humidity) is called a Hygrometer and is illustrated by Fig. 260 PRACTICAL HEATING AND VENTILATION 239. Various forms of this instrument have been devised; that shown by the illustration is a standard type. The atmosphere surrounding us is seldom dry or completely saturated with moisture and the amount of aqueous vapor held in suspension is very changeable. This fact bears an important part when considering the hygienic qualities of the atmosphere. As we have already noted, a certain amount of moisture in the air is essential to good health and the importance of maintaining the proper proportion of moisture in the atmosphere within our homes and public buildings we have commented upon in a former chapter of this book. Particularly is this true in hospitals or in the sick chamber. In speaking of the humidity in the air we hear much of the " dew point." Dew is formed by the radiation of heat from the surfaces of trees, plants, etc., consequently reducing the tempera- ture of the air near the immediate surfaces of such objects to the point of complete saturation, causing moisture to be deposited. With a complete heating and ventilating apparatus, that is, with an air heating, cleansing and moistening apparatus, any kind of climate may be produced and is registered or recorded by the Hygrometer. The Hygrometer has two thermometers a " dry " thermometer and a " wet " thermometer, as indicated by the illus- tration. These are mounted on the face of the instrument. The bulb of the dry thermometer is exposed to the air; the bulb of the wet thermometer is surrounded by a piece of silk, cotton or wick. As evaporation causes a loss of heat, the thermometer with the wet bulb will read lower than the other, provided there is any degree of dryness in the air. When the air is very dry the difference of register between the two thermometers will be great, the variation lessening according to the degree of moisture in the air, until at complete saturation both will read alike, as then there can be no evaporation. To use the hygrometer the wet bulb and attached wicking should be thoroughly saturated with water. The small reservoir under the wet bulb should be filled with water and the loose end of the wicking should dip into it. As fast as the water evaporates from the wet wicking cover- ing the bulb, it will draw its supply from the reservoir by capil- lary action of the wick and so keep the bulb constantly wet. MECHANICAL VENTILATION 261 Having prepared the hygrometer for work, expose it in the atmosphere to be tested for a period of fifteen or twenty minutes. Then note the readings of both thermometers, the dry and wet bulbs. Ascertain the number of degrees difference by subtraction. In the center of the instrument is a cylinder with a knob at the top for turning by hand, upon which is inscribed a series of col- umns of figures numbered at their headings from 1 to 22. These numbers represent the difference in the readings of the wet bulb and dry bulb thermometers and the columns show the relative humidity or percentage of moisture in the air for every degree of temperature indicated by the thermometers. Having ascer- tained the number of degrees difference in the reading of the thermometers, turn the knob of the cylinder until this number is exposed at the top of the column and opposite the opening in front and in line with the reading of the wet bulb thermometer. On the scale of the cylinder will be found the number representing the percentage of humidity in the atmosphere, absolute saturation being 100. Various forms of siphon gauges for water or mercury are manufactured for indicating vacuum or pressure. These are pro- vided with couplings for attaching to pipe or reservoir, the pres- sure or vacuum being shown by the difference in the level of the liquid in the two arms of the glass siphon. CHAPTER XXII Steam Appliances THE appliances used in connection with a steam boiler for power or heating purposes are many and varied in character. Steam Traps for removing the water of condensation without waste of steam, Separators for removing oil and other impurities from the water within the apparatus, or the water held in sus- pension in saturated steam, Steam Pumps, Inspirators, Injectors, Boiler Feeders and Return Traps for returning the water of condensation or feed water to the boiler against whatever pressure is used, Mechanical Apparatus for automatically controlling the draught, Pump Governors and Feed-water Heaters, etc., all have their separate and several offices to perform. While our work has to do only with boilers as used for heat- ing and ventilation, the same conditions of handling the water of condensation, regulation of pressures and separation of impuri- ties apply as to a boiler used for power purposes. These steam specialties are so numerous and different in char- acter that we can illustrate but few of them, mention the salient features of each and discuss with our readers their work in con- nection with a power or heating apparatus. Steam Traps Steam traps are of two general kinds or classes : Those used to separate the water from and thereby relieve steam pipes or heating surfaces, and those used for returning to the boiler the water of condensation from the steam employed for heating or for mechanical purposes. In the first division there are many kinds : Expansion traps, whose action depends upon the difference in the expansion of two metals, such as the Heintz Trap, Fig. 240 and the Kieley Canti- 262 STEAM APPLIANCES lever Expansion Trap, Fig. 241 : Bucket or " Pot " Traps con- structed with a hollow metal bucket inside the trap, which, when FIG. 240. Heintz trap. FIG. 241. Kieley cantilever expansion trap. filled with the return water, opens a valve, allowing the trap to operate and the bucket to empty. A trap of this character is FIG. 243. Nason bucket trap. FIG. 242. Albany bucket trap. shown by Fig. 242, which illustrates the Albany Trap, and Fig. 243 which illustrates a trap of the familiar Nason type. 264 PRACTICAL HEATING AND VENTILATION The Kieley Special Trap, shown by Fig. 244 is not unlike the others in the principle of making use of a metal bucket. It FIG. 244. Kieley special trap. has, however, a special form of valve a balanced or double- seated valve, giving it an extremely large capacity for handling rapid condensation, as in a low-pressure heating apparatus. FIG. 245. Wright emergency trap. The float type of trap has many adherents. The Wright Emergency Trap, as illustrated by Fig. 245, is a particularly STEAM APPLIANCES 265 good representation of this type of trap, the illustration being so clear as to require almost no explanation. The condensation enters the trap through the inlet opening and fills the pot some- what more than half of its height, when the copper float rises, opening the discharge valves (of which there are three) at the top of the trap. Note by the small detail of the valve shown on the left of the illustration that the points of the three valve stems are set at varying heights. The center valve is the one in regular operation. Should a rush of water enter the trap, the float will quickly rise, the arms at the bottom engaging the rods on either side cnnecting with the valve stems, thus allowing the three valves to act in unison while the rush of water continues. FIG. 246. Standard ball float trap. Another of this type of trap is shown by illustration Fig. 246, which is the Standard Ball Float Trap, the operation of which is quite similar to that already described, excepting that it has but one valve. Other traps combining the float principle with the balanced valve, or with the expansion feature are manufactured, as are also others making use of the expansion and contraction of some chemi- cal or sensitive liquid. Those illustrated, however, may be con- sidered as representative types of traps employing the principles described. The open trap discharging into the atmosphere, or against slight pressure was invented by Mr. Joseph Nason, a heating 266 PRACTICAL HEATING AND VENTILATION engineer and contractor of New York, and the original Nason Trap was quite similar to those of the same name in use at the present time. Return Traps The returning of the water of condensation to a boiler on which the pressure is much greater than on the return pipes pre- sents an altogether different problem from that of drawing the water from a system without the loss of steam. To Mr. Jas. H. Blessing, of Albany, is due the credit for the first successful efforts in this direction. Circumstances arising with regard to the heating of the factory of Townsend & Jackson, known as the Townsend Furnace & Machine Works, by whom Mr. Blessing was employed as superintendent, made it necessary to return the water of condensation to the boiler by some other means than gravity. Mr. Blessing tells some interesting facts regarding this. He says: " During the year 1870 the proprietors of the Townsend works deemed it best to remove their establishment down to the river front. As the area of the new works was to be considerably greater than that of the old, it was necessary to make some changes in the heating system. I concluded to use the exhaust steam for heating the foundry and part of the upper floors, and to heat the offices, machine and pattern shops with direct steam taken from a boiler to be specially installed for that purpose. I intended that the boiler should be set in a pit so that the water of condensation from the heating system of the lower floors would gravitate into it. After having settled on this plan, be- lieving it to be all right, I arranged with a contractor to remove as much as possible of the old heating system and replace it in the new works and to furnish all the extra pipe and fittings neces- sary to complete the system as I had planned it. After arrang- ing with the contractor I paid very little attention to the matter as we had over a hundred men employed in the different shops and my time and attention were fully occupied with the details of the business and the removal of the works. Therefore, I did not discover the gross error I had made until after nearly all the work was done, with the exception of the setting of the boiler. STEAM APPLIANCES 267 You can imagine my position, after explaining to my employers what a simple and effective plan I had devised for the return of the water of condensation back to the boiler, when I learned how impracticable it was to place the boiler low enough to have the water from the lower floors gravitate into it, owing to the fact that each tide caused the level of the water in the river to rise higher than the fire box of the boiler. In order to overcome this condition it would be necessary to set the boiler in a tank anchored to prevent its floating. " This would have been very expensive and, under the circum- stances, impossible. " After having discovered the character of the problem that confronted me, my first thought was to secure a trap that would FIG. 247. Early type of Albany return trap. return the water of condensation to the boiler without the aid of pumps. After making a thorough inquiry, I failed to learn of any such device. " In an effort to solve the problem presented, my mind turned naturally to the thought of returning the water of condensation to the boiler by gravity, and my first experiments were all in that direction. My first return-steam traps, invented during the year 1871, Fig. 247, were placed above the water level in the boiler, the steam being taken from the steam space of the boiler and acting upon the upper side of a diaphragm contained within the 268 PRACTICAL HEATING AND VENTILATION trap and intended for equalizing the pressures. This diaphragm acted simply as a dividing wall between the water on the one side and the steam on the other. The steam used for each discharge of water from the trap was, as in the case of a steam pump, ex- hausted to the atmosphere. Although the diaphragm trap was successful in its operation, yet it failed to return all of the water and did not make up for the error I had made. " In my experiments with the diaphragm trap several inter- esting facts came to light. Among other things, I discovered that the inlet pipe for conveying the water of condensation to the trap receiver from the coils, contained steam and water, for, after the first condensation, due to the extra amount of steam condensed when steam was first let into the heating apparatus, was worked off by a few rapid discharges of the trap, it would require several minutes to collect water enough to again fill the trap. While this was filling up one could hear the inlet check valve on the inlet pipe rattling on its seat, caused by the water and steam passing through it. As a result of this observation and the experiments I had been making, it occurred to me that after all the coils and radiators were only a part of the direct steam pipe that conveyed the steam from the boiler through them and finally terminated in the small pipes used for collecting the water of condensation. " If this smaller return pipe were connected, so I reasoned, to the top of a vessel of proper size placed a certain distance above the water level of the boiler, the water and steam would pass over into such receiver, the water falling to the bottom and sepa- rating itself from the steam. The steam pressure in the receiving vessel would be about the same as the pressure in the system at its farthest point from the boiler. If this pressure were near enough to that in the boiler and the receiver were placed at a height sufficient above the water level in the boiler so that the solid water column would make up for the difference in the pres- sures, the water would gravitate back into the boiler through a return pipe extending from the bottom of the receiver. With this understanding of the conditions, I prepared a spherical vessel twelve inches in diameter as the receiver to be used in the system with which I was experimenting. I believed that a receiver of STEAM APPLIANCES 269 the size mentioned would be ample for the purpose as the capacity was less than one gallon per minute. The receiver was placed on the floor above the boiler where the coils were situated and about nine feet above the water level in the boiler. After the receiver was connected up and steam turned on and the first water and air removed by blowing to the atmosphere, circulation began and was perfectly maintained. This, I believe, was the first steam loop ever made to return the water of condensation from a steam sys- tem situated below the water level of the boiler whence the water issued in the form of steam, all without in any way opening to the atmosphere. " After the steam loop had been in successful operation for some time in the Townsend & Jackson works I thought I would test it in another place. Accordingly, I selected the plant of Mess. Weed & Parsons, printers, of Albany, where a modern heat- ing system, using steam direct from the boiler, had just been installed. On investigation, I found a place about ten feet above the water level in the boiler where the receiver could be placed. After getting the system connected up and making several at- tempts to start a circulation, I met only with failure. I next concluded to try the steam pressures and found a difference of about eight pounds between that of the boiler and the coils. This explained to me the reason for the failure to get up a circulation, for it would require for the height of the return column of water about twenty-four feet, or over twice the space available. Owing to the conditions under which the system was installed I could not get a place sufficiently high for the receiver and could not without great expense enlarge the main steam-supply pipe so as to make the pressures more nearly equal. I then made a change by taking the receiver and suspending it on one end of a counter- balanced lever and added a steam valve for admitting steam direct from the boiler into the top of the receiver for the purpose of equalizing the pressure with that in the boiler. This steam valve was caused to open and close automatically by the rising and falling of the receiver. In the form here shown in the cut, Fig. 248, this trap was known as the Albany Gravity Return-steam Trap." During the period following the introduction of this trap, 270 PRACTICAL HEATING AND VENTILATION improvements were added and the Albany Return Trap as used at the present time has all valves and other mechanism inclosed within the body of the Trap itself. As will be seen by the illus- FIG. 248. Albany gravity return trap. tration, Fig. 249, the bucket of the Trap rests on a hinged pivot at one side of the bucket. As the return water enters the space between the bucket and the outer wall of the Trap, the bucket is FIG. 249. The Albany return trap. tilted slightly, allowing the ball weight " C " to slide to the oppo- site side of the Trap, giving a sudden impetus to the tilting move- ment, which seats the equalizing steam valve and at the same time STEAM APPLIANCES 271 opens the exhaust valve. The bucket is held in this position until the water flows over the top edge and fills it, when it again tilts downward under the impetus of the preponderance of weight and the movement of the ball weight returning to its original posi- tion. This movement opens the equalizing valve, admitting steam direct from the boiler into the trap, thus equalizing the pressure between the boiler and the trap, whereupon the water in the bucket will feed through the siphon-pipe connection down and into the boiler. As the bucket is again tilted it closes the equal- Radiators above Water Level in Boilei FIG. 250. Method of connecting Albany return trap. izing valve against the steam pressure, the Trap refilling as before. The Return Trap should be located at least three feet above the water line of the boiler. We illustrate by Fig. 250 the general method of connecting the trap. The condensation collects in the cast-iron pot or re- ceiver. The pressure on this receiver from the heating system raises the water to the trap, which returns it to the boiler. There are several kinds of return traps, the same general principle of equalizing pressures being employed, although the methods of operating the traps differ widely. The Champion and the Pratt & Cady Traps work by balanced weights. The Bundy Return Trap differs from all of the others in that no 272 PRACTICAL HEATING AND VENTILATION movable or balanced weights are used. Fig. 251 shows the form of this trap and the method of making connections. The trap consists of a cast-iron bowl which swings on trunnions, moving in a vertical travel. When the trap is empty the bowl rests against the top of the frame surrounding it, the weight of the ball on the overhanging lever holding it in this position when empty or while filling. When the bowl fills with water to a point where the weight of the water combined with the weight of the FIG. 251. Bundy return {rap and method of connecting. bowl overbalances the weight of the ball, the trap drops until it rests on the under side of the frame already alluded to. In making this movement it closes the air valve and opens the equal- izing valve, allowing the steam at boiler pressure to enter the bowl on top of the water, through the curved equalizing pipe shown in the bowl of the trap. Thus the pressures on the trap and the boiler are equalized. The water in the bowl now runs unob- structed out of the opening through which it entered the bowl and drops by gravity through the check valve on the return pipe STEAM APPLIANCES 273 and into the boiler. In returning to its first position the bowl closes the equalizing valve and opens the air valve and is again in readiness to receive the returning condensation. There must always be sufficient pressure on the returns or receiver to lift the water to the trap. Where this pressure (one pound for each two feet of lift) is not available, the duplex system, or use of two traps, is necessary. The office of the lower or secondary trap is to receive the water of condensation from the heating coils, or other source, by gravity and in turn lift or deliver it to the upper trap, which returns it to the boiler. It is claimed for return traps that they will handle water much hotter than a pump and with less loss in heat units. Separators Separators for removing moisture from steam and oil, or other impurities from feed water, are made in various forms. The nature of all of them is to receive the steam through the inlet FIG. 252. Kieley separator. opening of the separator, directing it against a series of baffle plates. This action removes the oil or water and delivers the purified steam without loss of pressure into the supply main of the heating system. The oil or water so extracted drips into the 274 PRACTICAL HEATING AND VENTILATION lower chamber of the separator, from which it is removed through a drip pipe. On an exhaust heating system the separator is in- dispensable. When used to extract oil or other impurities from the exhaust it is placed on the exhaust pipe with the baffle plates facing toward the engine. When employed to remove the moist- ure from steam it is placed on the main steam pipe with the plates facing toward the boiler. Many separators are in satisfactory use. An Austin, Bundy, FIG. 253. Bundy separator. FIG. 254. Bundy separator baffle or separating plate. Kieley, or other make, may be found in the boiler room of nearly every power or heating plant. As representative of the separators having stationary cast- iron bafflle plates in the chamber of the separator, we illustrate the Kieley design, Fig. 252. The Bundy Separator, Fig. 253, is illustrative of the type of separator with removable baffle plates and shows clearly the character of it. A nest of six or more baffle plates, or more prop- STEAM APPLIANCES 275 erly, separating plates, as shown by Fig. 254, are grouped in the upper chamber of the separator. The pillars of these plates are staggered, the steam passing through and around them. Each pillar or column is channeled its entire length, the small openings through the face of each column communicating with the vertical channel through which the water or oil passes by gravity to the receiving chamber below. The plates may be easily removed for cleaning, a very neces- sary factor when the separator is employed to remove oil or other impurities from the exhaust. Feed-water Heaters When the hot water from the condensed steam is used for other purposes and it is necessary to feed the boiler with fresh water, or, again, when the return water, trapped or pumped to the boiler, has lost the bulk of heat units contained in it, a very great saving may be effected by reheating this water before sup- plying it to the boiler. Engineers are agreed that for each 10 degrees this water is heated, a saving of 1 per cent of the fuel is realized. Before the closed type of feed-water heater came into use it was customary to run the water of condensation or the fresh water into an open tank or hot well, heating it by steam coils or by turning the exhaust into it, whence it was pumped into the boiler. Frequently the water supplied to the feed-water heater is partially heated by coils in drip tanks, thereby making use of heat units which otherwise might be wasted. Progress along the lines of steam engineering has shown the advisability of saving all heat units possible, being conducive to economy in the con- sumption of fuel. The fact has been demonstrated that the feed- ing of cold water direct to the boiler creates a straining, due to expansion and contraction, which must necessarily shorten the life of the boiler. When the temperature of the feed water is raised from an average of 60 degrees to a temperature of from 200 to 212 de- grees, a saving of about 15 per cent of the fuel is effected. With- out entering into a discussion of the relative merits of various 276 PRACTICAL HEATING AND VENTILATION types of feed-water heaters we may say that a good heater to adopt is one which is so constructed as to admit of easy cleaning, one whose area for the passage of the exhaust is sufficiently great FIG. 255. Bundy type of feed-water heater. to show no back pressure, and one in which the expansion and contraction of the inner tubes are fully provided for. Fig. 255 illustrates one type of a feed-water heater of this character. Steam Pumps One method of returning water to a boiler is by the use of a boiler feed pump. It is entirely probable that no branch of steam engineering has received more attention than that of pump- ing machinery. Steam pumps are manufactured in a multitude of designs and sizes for regular and special purposes, the evolu- tion of the pump having been carried to such an extent that all liquids, including chemicals, may be pumped from one receptacle and delivered to another under all sorts of conditions. Air or gas may be pumped and where steam power is not available, electrically operated pumps may be employed. Our use of pumps has only to do with pumping the water supply to the boiler or in removing the condensation from a heating system and creating and maintaining a vacuum on the heating system. STEAM APPLIANCES Boiler Feed Pumps For this purpose many standard makes are in evidence, among which may be mentioned the Knowles, Marsh, Blake and Deane Pumps. Fig. 256 illustrates the Knowles Direct-acting Steam Pump. This pump has many features to recommend it, chief of which is the simplicity of its construction. An auxiliary piston working in the steam chest drives the main valve, pre- venting what is known to engineers as a " dead center." The meaning conveyed by this expression is that there is a dead point which would stop and prevent the operation of the pump. FIG. 256. Knowles direct-acting steam pump. This piston driven backward and forward by the steam carries with it the main valve, which in turn supplies the steam to the main piston operating the pump, there being no point in the stroke at which either of the pistons is not open to direct steam pressure. The Marsh Boiler Feed Pump, Fig. 257, is the style used of this particular make for low pressure as with a heating appa- ratus. It is essential that a pump employed for this purpose shall be of sufficient size to allow of slow running. While reducing its pumping capacity this is best for low-pressure work. The motion 278 PRACTICAL HEATING AND VENTILATION FIG. 257. Marsh boiler feed pump. FIG. 258. Blake boiler feed pump. STEAM APPLIANCES 279 is less, requiring increased difference between the steam and water pistons. The Blake Pump used for boiler feed purposes in connection with a heating system is shown by Fig. 258. It has large direct water passages, conducive to the reducing of water friction and its operation is continuous at slow speed. Vacuum Pumps Certain mechanical work such as sugar making, etc., demand a " dry " vacuum pump. For vacuum systems of heating where FIG. 259. Marsh vacuum pump. FIG. 260. Knowles vacuum pump. the water of condensation and the air are handled together, the radiators and piping act as a condensing system. For this 280 PRACTICAL HEATING AND VENTILATION purpose pumps with large cylinders must be employed and the valve areas must be sufficiently large to insure the filling of the pump cylinder. It is customary to pump the water and air to a separating tank from which the water, at a high temperature, is delivered to the boiler, the air being delivered to the atmos- phere. Fig. 259 shows the Marsh type of vacuum pump and Fig. 260 the Knowles Vacuum Pump. Each of these types has a horizontal stroke; other styles have a vertical stroke and one, two or more cylinders. Pump Governors and Regulators To give the best of service steam pumps should be operated automatically. This is accomplished by a pump governor or regulator which controls the steam to the pump, thereby reducing Steam from Boiler To Pump FIG. 261. Kieley pump governor. or increasing the speed of the pump, according to the amount of condensation to be handled. On heating systems the establishing of a fixed water line, as may be accomplished with a pump gov- ernor, is a distinct advantage and a material help to the appa- ratus. There are two general types of pump governors, the first operating quite similar to a trap with a bucket or float. The Kieley Pump Governor, Fig. 261, has a ball float inside the cast- iron chamber, which rises and falls according to the amount of water delivered through the return pipe. This float connects with an arm or lever outside the casting, which operates the steam STEAM APPLIANCES 281 supply valve to the pump. The suction pipe to pump is connected at the bottom of the receiving chamber of the pump governor. The Blessing Pump Governor operates the steam valve by the rise and fall of an iron bucket within the receiving chamber of the governor, the general principle employed being quite similar to that already described. Quite different in style and operation are the pump regulators of the Knowles, Blake and Worthington types. These consist of a cast-iron receiver placed just above the pump. The drips or return pipes from the heating apparatus drain by gravity into K) .Cold Water Connection Discharge FIG. 262. Knowles pump and receiver. these receivers. In the interior of each one is placed a float and balance valve. The return water enters the receiver through an opening in the top and falls to the bottom of the receiver. When it accumulates in sufficient quantity to raise the float, the pump is started, which immediately takes the accumulation from the receiver and delivers it to the boiler. When the float falls again the steam supply to the pump is shut off and the pump ceases to work, the speed of it being regulated entirely by the amount of water entering the receiver. Fig. 262 shows the arrangement of a pump, receiver, and regulator of this character. PRACTICAL HEATING AND VENTILATION Back-Pressure Valves On exhaust-heating work there must be sufficient pressure to circulate the steam to all portions of the heating surfaces. The piping supplying the exhaust mains of the heating system should be plenty large in area in order to avoid an increase of back pres- sure on the engine. As has heretofore been stated, the exhaust from the engine is intermittent, the pressure on the exhaust pipe being greater or less, varying with the stroke of the engine. The heating system, acting as a condensing apparatus, does not al- ways use or condense all of the exhaust steam and there must es- sentially be a relief provided. This is accomplished by placing a special form of valve on the exhaust between the exhaust opening from the engine and the exhaust head, acting as a check on the FIG. 263. Back-pressure valve. steam in its forward motion toward the opening to the atmosphere. At the same time it provides a preventive to the backward motion of the steam. When the excess of pressure occurs the valve opens and relieves the pressure through the exhaust pipe to the atmos- phere. It is virtually an adjustable check valve with a lever and weight attachment for balancing the pressure. The unequal pres- sure from the engine causes a throbbing or vibration, which in many of the back-pressure valves is objectionable, owing to the noise. While there are many excellent makes of back-pressure valves, STEAM APPLIANCES 283 practically the same methods of operation are employed in each and every one, and for this reason we illustrate but the one type as shown by Fig. 263. Pressure-Reducing Valves When live steam is turned into the piping of a heating system it is at a high pressure, the same varying with the initial pressure at the boiler. Such a pressure must be reduced or checked before admission to the heating system. In order to accomplish this many styles of valves are used, w r hich may be set to regulate the pressure to any amount desired. As the regulation is from the low-pressure side of the valve, the reduced pressure remains con- stant, regardless of its fluctuation on the high-pressure side. In heating practice, gate valves are usually placed on the piping on either side of the reducing-pressure valve in order that the steam may be cut off from it to make adjustment or repairs. Injectors An injector is a device used for forcing feed water into a boiler against boiler pressure, that is to say, against whatever pres- sure may be carried on it. There are two distinct types of injec- tors, positive and automatic. The injector performs two offices. It lifts the water from whatever source of supply is provided and it also tempers it and delivers it into the boiler. The positive or double-tube injector has an overflow which closes mechanically and has two sets of jets, one for lifting the water, the other for forcing it into the boiler. The automatic injector has an overflow which opens and closes through the action of the injector itself and, as a usual thing, has but one set of jets. The operation of the injector is such that the steam at boiler pressure is passed into a vacuum through a very small opening. As this jet of steam strikes the water it is quickly condensed, creat- ing a velocity or forward movement of the water. All of the energy of the steam is imparted to the water warming it and forcing it into the boiler. Owing to these features the range of the injector depends upon the temperature of the feed water, it having a greater range, lift 284 PRACTICAL HEATING AND VENTILATION and pressure, with water at a low temperature. The best results are obtained with the feed water at from 60 to- 100 degrees Fahr., To Boiler FIG. 265. U. S. injector (interior). FIG. 264. U. S. injector. FIG. 266. Method of connecting injector. although the injector will satisfactorily handle water at a tem- perature up to 140 degrees. STEAM APPLIANCES 285 The double-tube injector is a German invention. There are several styles of injectors, one of which we illustrate by Fig. 264, showing an interior view of the same by Fig. 265. In order to show the method of connecting the steam supply, suction pipe and delivery to boiler, we illustrate one method of connection, Fig. 266. When the boiler feed water is supplied from a tank above the boiler, the suction pipe should be connected as shown by dotted lines. Gate or globe valves should be placed on steam supply and suction pipes and a check valve on a hori- zontal portion of the boiler feed pipe. The nearer the boiler and the farther from the injector this check valve is located, the better. A stopcock should be placed on the pipe between this check valve and the boiler. Inspirators This is a type of injector and operates along the same lines as the injector above described. That used for feeding boilers of the stationary type, as used for heating or power, is shown by Fig. 267 and the interior mechanism of it by Fig. 268. The name " inspirator " was given to it by Mr. John Hancock under conditions as follows: " In the year 1868, John Hancock, a civil engineer, began ex- periments having in view the entraining of air and compressing it to a certain extent, to be used as a blast for forges and fur- naces. These experiments led to the exhausting of air by means of a jet apparatus, which is now known commercially as an ejector. He found it possible by this method to create a vacuum to the extent of twenty-five or twenty-six inches mercury column ; also that water could be lifted from a depth of twenty-five feet and elevated into a tank. Later he found that he could make a jet apparatus which would, with its own steam pressure, force water into a boiler when the water flowed to it from an overhead tank or under pressure. This type of apparatus is now called a non- lifting injector. He therefore applied these two methods, using the ejector to lift the water from a well and deliver it into a tank located above the injector. The water then flowed to the injector and was forced into the boiler. This combination was placed in successful operation in several instances. 286 PRACTICAL HEATING AND VENTILATION " Following up this idea, Mr. Hancock became convinced that the tank could be eliminated and the ejector or lifting apparatus be attached direct to the injector or forcing apparatus. He ac- complished this arrangement and the two connected were emi- nently satisfactory ; in fact, much more so than the first arrange- STEAM FIG. 267. Hancock inspirator. FIG. 268. Interior mechanism of Hancock inspirator. ment, as the ejector varied its quantity of water as the steam pressure varied, which was just what the injector required to ob- tain a good working range. He considered this idea in the nature of an inspiration and thereupon called the apparatus the Han- cock Inspirator." STEAM APPLIANCES 287 Automatic Water Feeders Automatic water feeders, or devices for feeding water to the boiler in order to maintain a certain definite water line in the same, FIG. 269. Automatic water feeder Nason type. are manufactured in a great variety of styles. The action of the valves is controlled by a copper-ball float, the water raising this float until the normal level of the water line has been reached, when the valve to the water supply is closed. The pressure of the water supply must ex- ceed the pressure carried on the boiler. The Nason type of boiler feeder is shown by Fig. 269. The Lawler type of water feeder is shown by Fig. 270. As will be noted by the illustration, this feeder is used in place of the regu- lation water column and is provided with a water gauge. Water feeders are now manufactured which, when used on heating boilers, not only keep the boiler supplied to its normal water line, but also prevent the flooding of the boiler by reason of the sudden return to the boiler of any water of condensa- tion which might have become en- FIG. 270.-Lawler automatic trained in piping or radiators. water feeder. CHAPTER XXIII District Heating THIS type, if it may be so termed, of steam and hot-water heating owes its inception to an eminent engineer, Mr. Birdsall Holly, of Lockport, N. Y., who, in the year 1877, introduced the system of underground steam distribution which bears his name. The original plant, with about one mile of underground mains, was installed at Lockport, N. Y., then a city of about 20,000 inhabitants, and the first buildings connected with and heated by the same were five stores, seven residences and two churches, and the original system, with extensions and improve- ments, is now in operation. Mr. Holly's first idea in the construction of this plant was to make use of live steam, the main object being to relieve the users from the necessity of the care and attention essential where individual heating apparatus was used, and to eliminate the dirt and other unpleasant features unavoidably present in connection with the operation of a heating apparatus. Mr. Holly reasoned that those persons owning and operating such plants would pay well to be freed of such care and attention and the trouble oc- casioned by the purchasing and handling of fuel. In using steam from a district plant there would also be a freedom from the danger of fire consequent to the operation of a heating plant within each separate building. That the inventor reasoned along correct lines is clearly demon- strated by the fact that this original plant has been added to from time to time until some three hundred and fifty consumers are customers of the company operating it, the plant at the present time having in successful operation some six miles of street mains. Many obstacles, which had to be met or eliminated altogether, 288 DISTRICT HEATING 289 were encountered in the operation of such a plant and years of effort and experimenting were required to perfect it. The proper insulation of the pipes to prevent loss of heat by radiation from the street mains and service connections, the con- struction of devices for providing for expansion and contraction, anchorage, etc., together with other features of construction, were tested exhaustively in a practical manner, with the result that the Holly System is to-day free from the defects prevalent in its original form. The fact that steam can be manufactured in an isolated posi- tion, from cheap fuel at small expense and delivered without any considerable loss in temperature through ten miles or more of street mains, and the further circumstance that special devices regulate and register the amount of steam used by each consumer, all these, together with other incident conditions, have made this class of heating a paying investment and at this period there are hundreds of district systems in successful operation. The early methods of district heating were such that the water of condensation was returned to the central station through a system of piping separate from the steam mains. This has now been generally abandoned and the surplus of heat available in the water of condensation is fed through a trap to an economizing coil (made usually of several sections of indirect radiation), where the remaining heat units are extracted and delivered to a room above through a register in the same manner as from an indirect radiator on an ordinary job of heating. The water of condensa- tion is then carried to a special condensation meter, where it is weighed and quantities registered and is finally emptied into the sewer. The system of piping in the building to be heated may be of either the one-pipe or two-pipe style, and, if hot-water heat is em- ployed, a special type of hot-water heater is used, through which the steam passes in much the same manner as through a feed-water heater. In this event steam rather than coal or other fuel, is used to heat the water. Probably the best adaptation of district steam heating is by the method of piping known as the " Atmospheric System." The hot-water type of radiator is used and the steam is supplied to each radiator at the top of one end through a 290 PRACTICAL HEATING AND VENTILATION special form of valve with small ports or openings in the seat. Thus a valve may be opened one, two, three or four ports, supply- ing a greater or lesser amount of heat to a radiator, or such an amount as may be required to maintain a uniform temperature within the room to be heated. This system is operated under a few ounces of pressure above that of the atmosphere and such heat units as are contained in the steam or water are extracted before the water of condensation enters the returns. A finely adjusted regulating pressure valve is used on the supply from the street main and as the condensation is metered and weighed the consumer pays only for such heat as he has used. As stated before, the first idea of central-station heating was that of the production and sale of live steam. At the present time this class of enterprise has found favor with the management of large electric lighting and railway plants, as it gives an oppor- tunity to increase their revenues by providing a profitable method for disposing of their exhaust steam. There are several systems of central-station steam heating now in use. The different systems vary somewhat in the manner of constructing the piping or underground mains and also in the method of handling the steam supply after it has been introduced to the building to be heated. We would divide the methods of central-station or district steam heating into two classes, the first, where the steam is manufactured only for the purpose of heating; the second, where the steam generated is used for power and the " by-product," if so it may be termed, is used for heating pur- poses. It is the latter method which is more generally used, and a wonderful saving is effected by the company which disposes of their exhaust in this manner. It is customary to divide the boiler power of each station into units of 150 or 200 H. P. each. A one-thousand H. P. plant would have five 200 H. P. boilers, one of them held in reserve, the other four in daily operation. It has been shown that after allowing this one-fifth, or 20$, boiler reserve, a further allowance of 15$ for heating feed water and a 5$ loss for leakage and deterioration from condensation, each of the 1,000 H. P. capacity of the plant can supply 80 sq. ft. of radiation with the necessary units of heat, or 80,000 sq. ft. of ordinary cast-iron radiation. During periods of intense cold DISTRICT HEATING weather the reserve boiler may be employed to prevent overwork on the part of those in regular use. It is worth noting that in many instances the revenue from the steam sold for heating has been sufficient to pay the fuel bill for the entire plant for the full twelve months of the year. Central-Station Hot- Water Heating Heating by hot water supplied from a central station has during the past ten years resulted in the installation of over one hundred plants of this nature. While the process of heating sev- eral buildings from a single plant is not new, it having been more or less used for fifty years or more, the improvements in methods of installation and control have advanced materially during the last decade. The systems of Evans-Almiral Company, H. T. Yar- yan and also Schott's balanced column system have been largely used and to-day there are over one hundred of them in operation. This work includes some features which will prove of interest to the fitter. The matter of estimating the amount of radiation required to heat a building depends upon the system employed and the manner of operating the plant. Some systems deliver water at 140 at freezing and raise or lower the temperature one degree for each degree of variation of the outside temperature. Provided the service or street mains are large and there is a suffi- cient amount of radiation installed, this plan works out nicely. We would prefer seeing the water at 155 or 160 at freezing and then vary the temperature according to the weather. TABLE XXVI Outside Temperature. Water Temperature. 60 120 50 140 40 150 30 160 An estimated loss 20 10 180 190 of 3 in tempera- ture for each mile Zero 200 delivered. -10 210 -20 220 ' -30 230 292 PRACTICAL HEATING AND VENTILATION In estimating radiation one square foot of radiating surface for each square foot of glass surface and its equivalent in exposed wall and cubical contents will, as a rule, prove a sufficient ratio in figuring work. Schott advises a schedule of temperatures, as shown on page 291. As to which system is preferable steam or hot water it would be a hard matter to decide, as each one seems to have par- ticular and individual advantages peculiar to itself and not pos- sessed by the other. CHAPTER XXIV Pipe and Boiler Covering THE insulating of exposed boiler or heater surfaces and pipe for conveying hot air, steam or hot water and the value of so doing are matters which ofttimes do not receive proper attention from the steam fitter or heating contractor. Many steam fitters doing work in a small way, installing but few jobs in the course of a season, look upon the subject of covering as an increased expenditure for material which, added to the cost of the work, is apt to destroy all their chances for securing the contracts for the jobs, and this especially if competition be close. An argu- ment of this kind is wrong in its entirety, and steam fitters gen- erally who are contracting for heating work should understand the benefits accruing from thoroughly covering the boiler and such exposed piping as is not used for radiating surface, and should become so familiar with the subject and so versed in its application that the owner may be enlightened as to the saving effected and thus be made to feel willing to pay whatever sum may be necessary for the work. Just as heat is conveyed by three distinct methods, viz., by radiation, by conduction and by convection, as explained in Chapter II, just so is heat lost or dissipated from the bare sur- faces of boilers, heaters and piping for conveying steam or hot water. What this loss is has been quite accurately determined by various authorities. One authority states that a square foot of uncovered pipe, filled with steam at 100 Ibs. pressure, will radiate and dissipate in a year the heat put into 3,716 pounds of steam by the economic combustion of 398 pounds of coal; thus 10 square feet of bare steam pipe (steam at 100 Ibs. pressure) corresponds approximately to the waste or loss of two tons of coal per annum. 294 PRACTICAL HEATING AND VENTILATION Some tests reported in Volume XXIII of the proceedings of the American Society of Mechanical Engineers (tests made in 1901) show that on 100 lineal feet of 2-inch pipe, carrying steam at 80 Ibs. pressure, tests based on 300 working days of 10 hours each, with temperature of room about 65 Fahr., a very ma- terial saving was effected. The following table shows the results of the test : TABLE XXVII Net Tons N ime of Pipe Covering. Condensa- tion per Hour Lbs. Net Tons of Coal consumed per Year. of Coal saved per Year by use of Cost of Coal per Net Ton. Net Saving in Cost of Coal per Annum by use of Covering. Approxi- mate Cost of Cover- ings. Covering. Bare Pipe 59.16 7.76 $4.00 $31.04 loss Asbestocel 13.47 1.83 5.93 4.00 23 . 72 saving $16.20 Asbetos Molded 14.35 1.96 5.80 4.00 23.20 " 15.95 Air Cell . . 14 60 1.99 5.77 4.00 23.08 " 15.90 When we consider that there are about 64 square feet of heat- ing surface in 100 lineal feet of %" pipe, the annual saving amounts practically to 35 cents per square foot, which will pay the entire cost of the covering, leaving the saving of future years as a clear profit on the investment. While the above tests were made at a comparatively high pressure, with 1 Ib. of coal evaporating about 11 Ibs. of water, the same proportionate showing may be made with steam at one or two Ibs. pressure or on hot-water piping where the temperature of water averages 160 degrees. Stated in a different manner, the saving effected by the use of covering on low-pressure steam or hot-water work averages from 10$ to 30$ of the entire yearly expense for fuel, dependent on the character and quality of the covering used. Asbestos, magnesia, mineral wool, cork, wood and felt paper are the materials principally employed in the manufacture of pipe covering, although for underground piping, ashes, charcoal and sawdust have been used. The thermal conductivity of the material used governs the ef- fective character of a covering applied to prevent loss of heat, the efficiency of asbestos, magnesia, hair felt or cork being greater than all other materials in this respect. PIPE AND BOILER COVERING 295 Asbestos is a fibrous rock, Fig. 271, found in many parts of the world. It lies in thin strata or layers and, when broken, separates in long silky fibers, which may be spun into threads FIG. 271. Asbestos rock. or woven into wicking or sheets. This material is not only fire- proof, but acid-proof as well and serves as an insulation for electric currents. Cork, as used for covering, is ground or granulated and then pressed into the desired shape. In places where the covering is FIG. 272. Method of fastening sectional pipe covering. affected by dampness or water, cork covering is, no doubt, su- perior to all others on account of its non-absorbent and odorless qualities. Pressed cork, magnesia, asbestos and, in fact, all coverings of 296 PRACTICAL HEATING AND VENTILATION this nature are manufactured in three-foot lengths and split lengthwise for easy adjustment on the piping. The different varieties have an outer covering of muslin or light canvas, glued or pasted on them, to give a finish. Covering is secured to the pipe by japanned tin or brass bands, as shown by Fig. 272. Air when confined within a space to prevent circulation is a non-conductor of heat and provides good insulation. A cover- ing which has met with much favor for low-pressure work and FIG. 273. Asbestos air-cell pipe covering. for hot-water piping is known as the " air-cell " covering. It is made of corrugated asbestos paper of various thicknesses. A cross section of this covering is illustrated by Fig. 273. As a rule, on ordinary heating work, the exposed boiler and heater surfaces and the pipe fittings are covered with a magnesia- asbestos plastic cement, mixed with water to the desired consist- ency and applied with a trowel. However, molded fittings may be obtained for use with all sectional covering. See Fig. 274. These are secured to the fittings by bands of tin or brass, as shown by illustration. For underground piping or for steam pipes run in the open there is probably no better type of covering than the Wyckoff wood covering, as illustrated by Fig. 275. It is constructed of PIPE AND BOILER COVERING 297 eight thoroughly seasoned white pine staves, one inch thick, closely jointed together and wound with heavy galvanized steel wire, as shown by the illustration. It is then wrapped with two FIG. 274. Molded fittings. layers of heavy corrugated paper and again surrounded by a pine wood casing one inch in thickness, jointed and wire wound as before. When used underground, the exterior of the covering is FIG. 275. Wyckoff wood covering. completely coated with asphaltum pitch. A covering of this kind for such service will undoubtedly outlast all others and is thor- oughly effective as an insulator. There are now so many different varieties and grades of cov- erings on the market that it would be next to impossible to illus- 298 PRACTICAL HEATING AND VENTILATION trate and describe them, nor can we discuss the merits of the vari- ous makes. It is sufficient to state that in the same manner as the thickness and texture of clothing retain the heat of the human body so does insulation retain the heat within the steam or hot- water heating system, the quality of the covering governing the amount of heat retained and the saving made. CHAPTER XXV Temperature Regulation and Heat Control AUTOMATIC government of pressures and temperatures is one of the most important adjuncts to an artificial heating apparatus. We have shown in Chapter IV by illustration Fig. 35, a simple automatic steam damper regulator for regulating steam pres- sures, and by Figs. 36, 37 and 38, the application of it to the draught and check damper doors of a steam boiler. For the draught regulation of a high-pressure boiler, the damper regulator is heavier and more powerful, the rubber dia- phragm larger and the lever longer. A better regulator is one in which a compound lever is employed. A very slight movement of the rubber and the plunger resting against it will give a movement of from four to eight inches at the end of the lever where the chain to draught door is connected. In this style of regulator the rubber diaphragm is less apt to get strained or broken. Probably the best high-pressure damper regulator is one where a piston working in a cylinder is used, the piston being operated by water pressure. The employment of a compound lever on this type of regulator makes it extremely sensitive and will successfully operate the dampers at less than one-pound pres- sure. The Lock and Climax Regulators are of this character, that illustrated by Fig. 76 being the Imperial Climax. The successful and economical working of a steam boiler, either high or low pressure, depends largely upon the methods employed in regulating the pressure by means of the draught and check damper doors. All methods formerly applied depended upon the power furnished by the boiler itself. During the last twenty years such rapid strides have been made in temperature regulation that we now have regulators for controlling tempera- tures of air, water and steam, as well as other liquids and gases, and it would require a volume to adequately describe, illustrate 299 300 PRACTICAL HEATING AND VENTILATION and comment upon the various makes of regulators. We shall, therefore, select some regulators and systems representative of the various styles in use, and endeavor to give the reader an idea of the scope and character of this important industry. The automatic temperature regulator consists of three parts: () The thermostat, which by reason of the changes in the FIG. 276. Climax high-pressure regulator. temperatures of the room, furnishes the primary motor power for operating the damper-controlling device. (b) The means of transmitting this energy to the damper- controlling mechanism. (c) The damper-controlling mechanism, or device for open- ing or closing the dampers. The thermostat is placed within the room or at a point where the temperature is to be controlled. This is the primary motor TEMPERATURE REGULATION 301 operating the apparatus by means of certain mechanism employed for opening and closing the draught doors, check draught doors or dampers. The Powers Thermostat, Fig. 277, operates on the vapor prin- ciple. This disc is composed of two metal plates spun in cor- FIG. 277. The Powers' thermostat. rugations to give flexibility. Fastened together at the outside edges these plates form a hollow disc. A volatile liquid is placed within the disc. This liquid will boil and vaporize at a tem- perature below that of the water in the apparatus, or at a tem- FIG. 278. Regulator for hot-water heater or furnace. FIG. 279. Regulator for low-pressure steam boiler. perature of 50 degrees Fahr., generating a pressure which ex- pands the disc. At a temperature of 70 degrees a pressure of about six pounds to the square inch is exerted and this amount of pressure is sufficient to operate the valves controlling the com- pressed air. 302 PRACTICAL HEATING AND VENTILATION For the regulation of the ordinary house-heating apparatus, this regulator is made in three styles, the same disc as shown by Fig. 277 furnishing the primary motor power: (a) which controls the temperature of the rooms by operat- ing the draught and check doors of the hot-water heater or hot- air furnace by a diaphragm motor as shown by Fig. 278; (6) which controls the draught and check doors of a low- pressure steam heater by a diaphragm motor of double construc- tion, as shown by Fig. 279, which also takes the place of the ordinary pressure diaphragm regulator usually furnished with steam boilers ; (c) which regulates the temperature of the room by regu- lating the temperature of the water in a hot-water heater by means of a generator in connection with the diaphragm motor FIG. 280. Hot-water regulator. Fig. 280. This generator is attached directly to the heater and one of the flow pipes from the heater is connected to it. The diaphragm motor consists of two castings, slightly oval, bolted together, with an elastic material between. The reverse action of the plunger is accelerated by a steel spring placed around the plunger under the lever connection. The generator is a hol- low casting having a double shell or wall. The inner chamber is filled with cold water. The hot water passing from the heater into the flow pipe flows through the space between the inner and outer shells of the generator, thus surrounding the chamber into which the cold water has been placed. As the water in this inner chamber is under less pressure than that in the heater, it will TEMPERATURE REGULATION 303 boil quicker, producing a pressure which is exerted against the under side of the diaphragm through a pipe connected directly to it. This pressure is sufficient to operate the dampers of the heater and prevent the boiling of the water in the system. In order to obtain the best results from a regulator of this kind, it is essential that very light or counterbalanced check and FIG. 281. Counterbalanced check door. FIG. 282. Counterbalanced draught door. draught doors be used. Fig. 281 shows a very good style of check damper and Fig. 282 an excellent draught damper. The exertion of a very slight force will open or close either of these doors. The Powers System of controlling the temperature of a large building provides for the control of the valves admitting the FIG. 283. Powers' diaphragm radiator valve. FIG. 284. Thermostat for control- ling radiator valve. steam, or regulating the flow of hot water to the radiators. We know that an occupant of a room, by watching the thermometer and attending constantly to the operation of the radiator valves, 304 PRACTICAL HEATING AND VENTILATION may control the temperature of the room in a very satisfactory manner. The Powers System accomplishes this work automati- cally by means of diaphragm radiator valves, Fig. 283, which are placed on all radiators and operated by compressed air regulated by a thermostat, which is placed in each room and may be adjusted with a key to operate the valves at any temperature from 60 to 80 Fahr. This thermostat is shown by Fig. 284, without the cover. The cover is composed of metal, plated to correspond with the decoration of the room, and has a tested thermometer attached to its face. For controlling the mixing dampers of a blower system of heating, or the by-pass dampers of the air supply, the same type of thermostat as that already described is used, the dampers being operated by a diaphragm motor, Fig. 285. Compressed-air pipes lead from the storage tank to each of the thermostats and from the thermostat to each motor. The variation of temperature at the thermostat causes it to operate FIG. 285. Powers' diaphragm motor. as the primary force for releasing or retaining the air pressure upon the motor. With the air pressure removed the springs of the motor operate the dampers in a motion opposite to that ef- fected by the compressed air. Possibly a clearer conception of this arrangement may be had from Fig. 286, which shows an elevation of a fan apparatus as used in a school building. " A " shows the location of the thermostats in the school rooms ; " B " the motor ; " C " the mixing dampers controlled by them. " D " shows the location of the thermostat for controlling the temperature of the tempered air before admission to the fan ; " E " the motor which operates this damper. TEMPERATURE REGULATION 305 " F " shows the reservoir or storage tank for the compressed air. A pressure of air at fifteen pounds is automatically main- g 1 tained in this tank. The air compressor may be operated by steam, electric or hydraulic pressure. 306 PRACTICAL HEATING AND VENTILATION The operation of the National Regulator for the above class of work is quite similar to that already described. For control of a direct-heating apparatus a diaphragm valve is used on the radiators, and for a fan system a diaphragm or damper motor is used and compressed air is employed to operate each of these. FIG. 287. National regulator thermostat. FIG. 288. National regulator ther- mostat interior mechanism. The thermostat, however, is entirely different from all others, a vulcanized rubber tube being the element made use of in con- trolling the compressed-air force which operates the system. Fig. 287 shows the thermostat and the ornamental thermometer used in connection with it. Contained within the rubber tube are the air valve and the valves for operating the compressed air. Vul- canized rubber is very sensitive to changes of temperature, ex- panding or contracting instantly with the varying temperatures TEMPERATURE REGULATION 307 of the room, and when such expansion or contraction occurs it results in the opening or closing of the compressed air valves. The interior of this thermostat is shown by Fig. 288. Two air pipes are used, one from the air reservoir to the thermostat and the other from the thermostat to the valve or motor. The expansion or lengthening, or the contraction or shorten- ing of the rubber tube A raises or sets the point of the rod K upon the seat M, opening or closing the valves of the air supply. For the regulation of the temperature of water in storage tanks we show the D. & R. (Davis & Roesch) regulator. Fig. FIG. 289. D. & R. tank regulator. 289 shows the application of it to a tank heated by a steam coil. The motor employed is a diaphragm valve, using the rubber dia- phragm against which water or air pressure is exerted to close the valve, a spring on the stem of the under side of the valve holding it open until the pressure upon the diaphragm is suffi- cient to close it. The primary motive power is obtained from a regulator with an expansion post or plug screwed into an 308 PRACTICAL HEATING AND VENTILATION opening of the tank and extending into the same, as shown on the illustration. The mechanism is such that the expansion of the post pushes a spring which opens a valve, allowing the pres- sure of the water supply, or compressed air, to close the diaphragm valve by exerting a pressure upon the diaphragm. When the temperature of the water cools sufficiently to allow the post within the regulator to contract, this pressure is removed, the diaphragm valve opening by the spring, and steam is allowed to enter the heating coil. In a slightly different form this regulator is made to use on tanks supplied directly from a hot-water heater and adapted for FIG. 290. The Howard thermostat. FIG. 291. Motor for Howard thermostat. domestic hot-water supply, pasteurizing or sterilizing, and is also employed for directly controlling the draught and check dampers of a hot-water heater. It is best known as a device to prevent the overheating of water in a storage-tank supply system. Of the regulators operated by expansion we show the Howard and the Minneapolis as representing two distinct types. Each of these regulators makes use of a motor having a strong spring mechanism which furnishes power to operate the dampers. The Howard thermostat is composed of a sensitive plate, tri- TEMPERATURE REGULATION 309 angular in form, as shown by Fig. 290, attached to the side wall of the room. As the temperature rises, the plate curves or warps toward the wall. A wire and chain connection concealed within the partition leads from the top of the plate, over frictionless pulleys, to a weight within the motor box. The relaxing of this wire and chain allows the weight to drop sufficiently to release the motor, which makes one half turn of the crank arbor, when it stops automatically. The crank connecting with chain to the check damper, points down, holding the check damper door open; the crank connecting with the draught door, points up, slacking the FIG. 292. Method of attaching Howard thermostat. chain connection to the draught door, which closes by its own weight, or, if this be insufficient, by a weight attached to the bot- tom of it. As the temperature of the room cools below the degree of heat desired, this action is reversed, the check door being closed and the draught door opened. This is better illustrated by Fig. 291 which shows the mechanism of the motor, a thenno- :ic plate being attached to show the operation of the weight hie to the curving of the plate. The operation of the motor and the method. of attaching the chains to draught and check doors are clearly illustrated by Fig. The spring of the motor is occasionally wound with a key. 310 PRACTICAL HEATING AND VENTILATION The motor of the Minneapolis regulator and the method of attaching the chain connections to the draught and check doors are quite similar to that already described. Otherwise the regulator consists of a thermostat and two cells of open circuit battery. The thermostat, Fig. 293, is operated by the expansion and con- traction of a curved metal blade, imparting a side motion to a suspended arm, as illustrated by Fig. 294, which shows the ther- mostat with the screen removed. The wires from the battery are connected to the two posts shown just above the indicator of the FIG. 293. Minneapolis thermostat. FIG. 294. Interior of Min- neapolis thermostat. thermostat. Needle-pointed adjustable set screws pass through these posts, the pendant blade hanging between them. As the temperature of the room rises, the side motion of the pendant moves it against the point of one set screw, forming a contact, which closes the electric circuit. As the circuit is closed an electric current flows through the magnets of the motor, releas- ing the brake, and the driving shaft of the motor makes a half revolution. As the temperature of the room lowers, the project- ing arm or pendant is, by contraction of the circular blade, TEMPERATURE REGULATION 311 thrown against the opposite pin, when the operation above de- scribed is reversed. The releasing feature of the motor consists of a pair of magnets, which become energized and attract an armature. The movement of the armature releases the motor, and when it starts, the armature is secured until the driving shaft of the motor makes a half revolution, when it resumes its normal position. Temperature controlling devices of the Howard and Min- neapolis types are best adapted for operating the dampers of the boiler or heater of a low-pressure heating apparatus. The Lawler thermostatic regulator shown by Fig. 295 is of another type. The expansion of the metal used is multiplied by a FIG. 295. The Lawler thermostat. series of levers to a range or force sufficient to operate the dam- pers of a steam or hot-water heating apparatus. It is also used, with a slight variation of the adjustment of the levers, to control the temperature of water in a storage tank for domestic or other use, the mixing of water to a certain temperature for baths, or for the controlling of the air supply of an indirect heating system. The Johnson System is one of the oldest of the systems of automatic control of temperatures. The motive force employed is compressed air, which is supplied by an automatic air com- pressor and stored in a tank. For ordinary service a hydraulic 312 PRACTICAL HEATING AND VENTILATION air compressor, Fig. 296, is used. This is connected to the water supply to the building and to some convenient waste pipe. It is noiseless in operation and automatically keeps up a pressure of FIG. 297. Johnson thermostat. FIG. 298. Mechanism of Johnson thermostat. FIG. 296. Johnson hy- draulic air compressor. from ten to fifteen pounds. Compressors are also furnished which operate by electric power and by steam. A thermostat is placed on the wall of each room in which the heat is to be regulated. The external appearance of this thermo- stat is shown by Fig. 297 ; the interior mechanism is shown by Fig. 298. The strip E is composed of two metals, soldered to- gether. Observe that the top of this strip is fastened to D ; TEMPERATURE REGULATION 313 the bottom, forming a hook, is fastened to the frame of the ther- mostat. A variation of but two degrees in the temperature of a room will cause this little tongue to expand, moving D and operating the valve of the air pipe. Two air pipes are connected to the upper part of the thermostat, one of them being the direct connection from the air main from the storage tank. The other connects the thermostat with the air motor of the valve at the radiator or w r ith the damper to be operated, thus directly oper- ating the valve and limiting the steam supply at each radiator or the flow of hot water to it, if it be a hot-water system, or the air-mixing dampers should it be a blower system. In order that the operation of the diaphragm valve may be clearly understood we show by Fig. 299 a sectional view of A B FIG. 300. Exterior of dia- phragm radiator valve. FIG. 299. Interior of diaphragm radiator valve. it. D and E show the openings for supply pipe and radi- ator connections. C is the seat of the valve and B the disc. Up to this point the body of the valve is built the same as an ordinary radiator valve. The frame supporting the dia- phragm is adjusted to the valve immediately below the stuff- ing box. A spring is slipped on the valve spindle and an oval shell, with air opening A, is fastened to the saddle or frame. 314 PRACTICAL HEATING AND VENTILATION To the under side of this shell is placed a rubber diaphragm. Note that in place of the valve wheel on the top of the valve spindle is a curved top fitting against the rubber diaphragm. The spring G keeps the valve open until the temperature of the room is sufficiently high for the thermostat to open the air valve and admit the compressed air to the chamber F, which presses down on the diaphragm, closing the valve and holding it in this position as long as the temperature of the room is above FIG. 301. Double damper for round flue. FIG. 302. Double damper for square flue. the point desired. When the temperature cools to such a degree as to cause the thermostat to act, the air pressure is removed and the spring G opens the valve. Fig. 300 shows an exterior view of the valve. The action of the thermostat is positive and quick in moving the valves. When impelling the dampers of a fan or hot-air system, that is, the air supply, another form of the thermostat is used, which operates gradually. This is also employed on a hot-water heating apparatus. TEMPERATURE REGULATION 315 Special forms of thermostats for air ducts, hot-water tank supply, etc., etc., are applied in connection with the Johnson pneu- matic system, and a system for handling the valves of a vapor system of heating is one of their achievements of later date. When handling air or controlling the temperature in the air ducts of a " hot and cold " or fan system the air motor is attached to the dampers as shown by Fig. 301, which shows a double dam- per for a round flue, or by Fig. 302, which shows a double square damper. The value of a successful system of heat control is not meas- ured entirely by the saving in fuel, which is variously estimated from 20^ to 35^; the fact of having an apparatus which without any thought or action from the occupants of a room or building, will automatically maintain the temperature at any desired degree, is something on which a value cannot very readily be placed. In schools, the teachers are relieved from the time lost and attention given the heating apparatus, in hospitals the value of an even temperature cannot be calculated, while for our homes, churches and offices the results from temperature regulation cannot be meaiured. CHAPTER XXVI Business Methods THERE are certain business methods in connection with the estimating on, the contracting for and the installing of an appa- ratus for heating and ventilation, which should be adopted by those already engaged in or about to enter into the business of contracting for work of this character. Quite frequently the owner of a building will let his heating work to the contractor whose bid for the job may not be the lowest, but who has de- scribed his proposition and appliances in a clear and concise manner, who has submitted a bid or proposal itemizing and enu- merating the various portions of the apparatus and the com- mendatory features of whose proposition are reinforced by a care- fully worded guaranty, covering the character of materials and class of workmanship to be furnished on the work. Such a business method cannot fail to be compared with that of the contractor who, in submitting his figure, simply notes a few words upon a letterhead bearing his business title. The owner is justified in expecting a higher class of work from that heating man who approaches him in a business way and with business methods, and undoubtedly is willing to pay more for it. Estimating In this, as in nearly every other business, competition is apt to be close and consequently the estimate covering any heating work should be carefully prepared, diligence and caution being exercised that no important items are omitted. For this purpose an estimate book or a carefully arranged sheet should be em- ployed. Various large jobs require special items. The ordinary job of steam or hot-water heating may be thoroughly covered by the sample estimate sheet shown on the following pages. The 316 ...... e(l < 2 52 ii, rt *, \ -r o-Jb -^ ' 1 -| ^ ^ I gj c fe rf 3uo r j O O O O O 5 O ^5 O ^^ O O O O O CSOOGO 1>00OI>OOT IO *O V) O( '*O'*O500 CO O O O *O 00 O CO i i I-H CO CO CO i i OOCO"- 1 I-H' X t i OOOO Ci O5 05 05 05 O5 X X 00 X 00 CO 5 5 CO CO rft Ot CO H. W 940 200 100 435 595 120 60 195 t of Indirect for Boiler ca in Mains and Risers n tion JII|KKi!ill ^^ OCOOOW& Direct Radiat Indirect Radi Add 50 per ce Add radiation 317 : : -- L 1 ^-M S i *Si2g _: . w . _^ fi "^cO^ | ^ U "5 ~^ ^ ""* "^ _._ c a ^.^ ^ , Jyil jus^ sJlJl-lllIllillllllilllla S 5 O 3 O5 O< O" COCO! ^r-(J>'-Hi-HOX(^'* O -^ r-i ,-H ioGO O5 CO * O5 i i TJ< ioj i : ; i : : ; ) H I i _co- J ^-,-H^-.-H-Hrs,-,^ n o^r-,ScaSrPcdOL>CJ C ^>=? ^^r^r^^3r?r^ ^ T * rH^fecOCOGO -^^00 O^COr- li IrH d 318 BUSINESS METHODS 319 detail represents an estimate for both steam and hot water for a brick three-story dwelling. The rule " 2 20 200 " is used in estimating the amount of radiation required; the prices inserted are fictitious, being given for the sole purpose of instructing our readers in the right course to pursue in correctly filling out the blanks on estimate sheet. Having estimated carefully the requirements of the work, size of heater, square feet of radiation, etc., etc., and checked over the cost figures to insure accuracy, the next step is to prepare a proposal and bid to submit to the owner. Proposal and Bid Printed forms arranged with spaces left blank for filling in with a pen may be procured for this purpose. It is our belief, however, that a typewritten form of proposal and bid is better suited to the purpose, as the printed forms must necessarily con- tain much matter which has to be crossed off or eliminated to cover certain work, but which, if excluded from the printed form, would for certain other work have to be inserted with a pen. We submit the following form of proposal as covering such detail as is necessary, and the bid attached becomes a legal contract after the signatures of both the contractor and the owner are added to it. The usual practice is to make two copies, the contractor signing both of them before submitting to the owner, who, if he accepts the proposition submitted, signs the acceptance clause and returns one copy to the heating contractor. As no one style of proposal can cover both steam and hot water work, we give separate forms for each. Where the dotted horizontal line " " occurs it denotes space in which the name of the boiler, radiator or other goods to be used, should be inserted. Proposal and Bid for Steam-Heating Apparatus General. These specifications are intended to cover a com- plete low-pressure steam-heating apparatus and it is understood that the same will be placed exactly as specified. 1. Boiler. I will furnish and erect in basement one No Steam Boiler. The exterior surface of the boiler, with 320 PRACTICAL HEATING AND VENTILATION the exception of the front, to be thoroughly covered with asbestos cement. The boiler will be provided with a complete set of trim- mings, which shall consist of automatic damper regulator, safety valve, water column and gauge, steam gauge and blow-off cock, and a complete set of firing tools, consisting of poker, slice bar, ash hoe and flue-cleaning brushes. Connection is to be made to the boiler from water pipe in basement to supply water to the boiler. A %" steam cock or globe valve will be placed on this pipe. 2. Foundation. A suitable and substantial brick and cement foundation for the boiler will be constructed by me. 3. Smoke Pipe. I will make necessary smoke connection from boiler to chimney by means of a galvanized iron smoke pipe .... inches in diameter, made of .... gauge iron and provided with a suitable damper. Owner is to provide a good chimney with sufficient draught for the work. SCHEDULE OF RADIATION Ft. Rad. Style. Height. Tap. Tempera- ture. First Floor. Parlor 1 Rad. 50 38" l 1 ^" 70 Sitting Room 1 " 60 38" w 70 Library . 1 " 50 38" \W 70 Dinino r Room 1 " 85 38" \W 70 Reception Hall .... 1 " 120 Pin Indirect 1J4X1" 70 (Stairs out) . Second Floor. Over Parlor Rad. 45 38" W 70 Over Sitting Room. Over Library 50 35 38" 38" w \y," 70 70 Over Dininw Room 45 38" \VA" 70 Over Hall 40 38" \y" 70 Bathroom 20 38" 1M" 70 Upper Hall (In- cluded in Recep- tion Hall). Third Floor. Front Chamber 1 Rad. 35 38" 1W 70 Middle Chamber 1 " 35 38" iu* 70 Rear Chamber 1 " 30 38" IM* 70 Bathroom 1 " 15 38" i" 70 715 sq. ft. BUSINESS METHODS 4. System of Warming. Building is to be warmed through- out by direct radiators, except as noted in the schedule of radia- tion. Radiators are to be of such kinds and heights as indicated. Wherever possible radiators will be placed along outside or ex- posed walls, their positions conforming, in so far as possible, to the wishes of the owner. 5. Radiation. I will erect and connect in building the total amount of radiating surface as indicated in the schedule given. All direct radiators shall be of make, .... or .... col- umn and divided and placed as specified. 6. Radiator Valves. All radiators shall be connected to piping, using a heavy pattern, wood wheel, Jenkins Disc radiator valve in each instance, with rough body, nickel plated all over, and of a size to conform to the tapping as given for each radi- ator in the schedule. 7. Air Valves. Each radiator and the steam mains in the basement, where necessary, shall be provided with a first-class automatic air valve of the pattern. 8. Pipe and Fittings. The piping is to be erected according to what is known as the system of gravity steam heat- ing. All main pipes shall have a pitch downward from the boiler at least l/o" in each 10 feet of length. All branches shall pitch upward from mains at least 1/2" ^ n ea ch 5 feet of length. In the event of it being necessary to pitch any branches downward, there will be a heel drip taken from the bottom of the riser so supplied and this drip will be connected into a wet return. All pipe to be of full weight and standard quality. All risers to be put up plumb and straight and all joints made tight. All fittings to be of the best gray iron, flat beaded and having clean-cut taper threads. 9. Hangers. Pipe in basement is to be hung on expansion pipe hangers of approved pattern, to allow of perfect freedom from expansion and contraction. 10. Cutting. I will do all necessary cutting of holes through floors and walls for the passage of pipes. Any breakages to walls or floors resulting from such work will be remedied by me and the walls and floors left in first-class condition. 11. Floor and Ceiling Plates. Where pipes pass through 322 PRACTICAL HEATING AND VENTILATION floors or ceilings, nickel-plated floor and ceiling plates shall be used. In case of pipes coming in contact with woodwork, the opening shall be lined with a good quality of tin. 12. Bronzing and Painting. All exposed piping and radia- tors above the basement will be given a priming coat of paint, followed by a coat of gold or aluminum bronze, as may be desired by the owner. All basement piping and all portions of the boiler uncovered shall be painted with black asphaltum. 13. Pipe Covering. All steam pipes in the basement, both flow and return, will be covered with low-pressure sec- tional pipe covering. Same to be neatly and securely fastened with brass bands placed three to each length of covering. All fittings to be covered with magnesia-asbestos plastic cement. 14. Setting of Direct-Indirect Radiators. I shall provide box bases with suitable dampers for all direct-indirect radiators and shall provide proper wall boxes to be set by the mason in the walls of the building. On connecting the radiator to the piping will make proper connection from the wall box to the box base by means of a galvanized iron duct or sleeve. 15. Hanging Indirect Radiators. All indirect radiators shall be suspended from the ceiling of the basement by suitable wrought iron hangers, at such a height that the bottom of the radiators will be at least 18" above the water line of boiler. All stacks of indirect radiation so hung shall be piped in such a manner as to permit of a free and easy circulation throughout their entire surfaces. 16. Casing, Air Ducts, etc. All indirect radiators shall be cased with a boxing made of heavy galvanized iron, constructed in such a manner that a portion of the bottom may be readily removed for cleaning purposes. The casing shall fit snugly around the sides of the radiators in order that the cold air shall pass between the surfaces instead of around them. The cold-air ducts will be made of galvanized iron and provided with a suitable damper and will be of such sizes as are necessary to supply the proper amount of cold air to the radiators. The hot-air duct shall be connected from the top of the casing to the register boxing in floor above. 17. Registers and Register Boxes. All registers shall be of BUSINESS METHODS 323 design. The area of the openings in same will not be less than the area of the warm-air duct. Registers will be set firmly in the wall or floor and flush with the same. Register boxes made of bright I. C. tin shall be provided for each of the register openings. (The clauses 14, 15, 16 and 17 should be omitted except where direct-indirect or indirect radiators are specified in a contract.) 18. In General. The material used in the construction of this apparatus will be new and of the best quality and the work put up by skilled workmen. When the apparatus is completed it will be fired up and tested in the presence of the owner or his repre- sentative and left in good order ready for use. 19. Guaranty. I guarantee this work in every respect: that when completed it shall be free from mechanical defects and noise- less in operation, and that after the apparatus shall have been accepted by the owner, any part thereof shall fail to accomplish the guaranty herein contained by reason of any defect due to my workmanship or the materials furnished, I agree to remedy such defects at once at my expense. It is understood that the term " defect " as above used shall not be construed as embracing such imperfections as would naturally follow improper treatment, accident, or the w r ear and tear of use. 20. Bid. I agree to furnish the material herein specified and do the work as herein enumerated for the sum of Seven Hundred and Thirty-nine Dollars and thirty-four cents ($739.34). Payments to be made as follows : One third when boiler is erected and material delivered on the job, one third when radiators are delivered and connected to the system, and the remaining one third after job shall have been completed and tested. (Signed) JOHN H. JONES. 21. Acceptance. To JOHN H. JONES, Heating Contractor. I hereby accept your proposal and bid for installing a com- plete steam-heating apparatus in my residence and for the same agree to pay you Seven Hundred and Thirty-nine Dollars and thirty-four cents ($739.34). Payments to be made as above specified. , , , .(Date) (Signed) R. D. BLANK. 324 PRACTICAL HEATING AND VENTILATION Proposal and Bid for Hot- Water Heating Apparatus General. These specifications are intended to cover a com- plete hot-water heating apparatus and it is understood that the same will be placed exactly as specified. 1. Heater. I will furnish and erect in basement one No Hot-water Heater. The exterior surface of the boiler, with the exception of the front, to be thoroughly covered with asbestos cement. The heater will be provided with a complete set of firing tools, consisting of poker, slice bar, ash hoe, and flue- cleaning brushes. 2. Foundation. A suitable and substantial brick and cement foundation for the heater will be constructed by me. 3. Smoke Pipe. I will make necessary smoke connection from heater to chimney by means of a galvanized iron smoke pipe .... inches in diameter, made of .... gauge iron and provided with a suitable damper. Owner is to provide a good chimney with sufficient draught for the work. SCHEDULE OF RADIATION Ft. Rad. Style. Height. ' Tap. Tempera- ture. First Floor. Parlor 1 Rad. 80 38" IV" 70 Sitting Room 1 " 95 38" 1 ! 4" 70 Library 1 " 80 38" ly * 70 Dining Room 2 Rads. 135 38" W 70 Reception Hall .... 1 Rad. 200 Pin Ir direct 70 Second Floor. Over Parlor Rad. 70 38" i/" 70 Over Sitting Room 80 38" 1/4" 70 Over Library 55 38" i" 70 Over Dining Room 70 38" IV" 70 Over Hall 65 38" W' 70 Bathroom 30 38" i" 70 i Upper Hall (In- cluded in Recep- tion Hall) Third Floor. Front Chamber 1 Rad. 55 38" i" 70 Middle Chamber 1 " 55 38" i" 70 Rear Chamber. . . . 1 " 50 38" i" 70 Bathroom 1 " 20 38" i" 70 1.140 sq.ft. BUSINESS METHODS 325 4>. System of Warming. Building is to be warmed through- out by direct radiators, except as noted in the schedule of radia- tion. Radiators are to be of such kinds and heights as indicated. Wherever possible, radiators will be placed along outside or ex- posed walls, their positions conforming, in so far as possible, to the wishes of the owner. 5. Radiation. I will erect and connect in building the total amount of radiating surface as indicated in the schedule given. All direct radiators shall be of make, . . .. or .... col- umn and divided and placed as specified. 6. Altitude Gauge and Thermometer. I shall place on the heater an altitude gauge in order to show at the heater the height of the water in the expansion tank. I shall also place on the heater a first-class hot-water thermometer. 7. Expansion Tank and Gauge. -I shall place on the work a heavy galvanized steel expansion tank of suitable size, with gauge glass complete. Tank to be placed on suitable shelf in bath or other room at least three feet above one of the highest radiators on the system. Overflow connection shall be made through roof. 8. Water Connection. I will make necessary water connec- tion from water pipe in basement to bottom and rear of heater and place on this connection a suitable globe valve or stopcock. 9. Radiator Valves and Union Elbows. Each radiator will be connected to the system of piping with a rough body, wood wheel, quick opening hot-water radiator valve with union, to be of heavy pattern and nickel plated all over. Return ends of radiators to be connected to return pipes by the use of a heavy pattern, nickel-plated brass union elbow. Sizes of valves and elbows to conform to the tappings as given in above schedule of radiation. 10. Air Valves. Each radiator shall be provided with a lock- shield nickel-plated brass air valve operated with a key. 11. Pipe and Fittings. System of piping used shall be the gravity return system of hot-water piping. All mains shall pitch upward from boiler at least 1" in each 10 feet of length, and all branches shall pitch upward from mains at least 1" in each 5 feet of length. All flow and return mains to be put up plumb and straight and all joints made tight. All pipe to be of best quality 326 PRACTICAL HEATING AND VENTILATION wrought iron, of standard weight, and all fittings to be of the best gray iron of heavy pattern, flat beaded, having clean-cut taper threads. 12. Hangers. Pipe in basement is to be hung on expansion pipe hangers of approved pattern, to allow of perfect freedom from expansion and contraction. 13. Cutting. I will do all necessary cutting of holes through floors and walls for the passage of pipes. Any breakages to walls or floors resulting from such work will be remedied by me and the walls and floors left in first-class condition. 14. Floor and Ceiling Plates. Where pipes pass through floors or ceilings, nickel-plated floor and ceiling plates shall be used. In case of pipes coming in contact with woodwork, the opening shall be lined with a good quality of tin. 15. Bronzing and Painting. All exposed piping and radi- ators above the basement will be given a priming coat of paint, followed by a coat of gold or aluminum bronze, as may be selected by the owner. All basement piping and all portions of the boiler uncovered shall be painted with black asphaltum. 16. Pipe Covering. All pipes in the basement, both flow and return, will be covered with low-pressure sectional pipe covering. Same to be neatly and securely fastened with brass bands placed three to each length of the covering. All fittings to be covered with magnesia-asbestos plastic cement. 17. Setting of Direct-Indirect Radiators. I shall provide box bases with suitable dampers for all direct-indirect radiators and shall provide proper wall boxes to be set by the mason in the walls of the building. On connecting the radiator to the piping I will make proper connection from the wall box to the box base by means of a galvanized iron duct or sleeve. 18. Hanging Indirect Radiators. All indirect radiators shall be suspended from the ceiling of the basement by suitable wrought- iron hangers. The connections to the same shall be made in such a manner as to permit of a perfect circulation throughout their entire surfaces. 19. Casing, Air Ducts, etc. All indirect radiators shall be cased with a boxing made of heavy galvanized iron, constructed in such a manner that a portion of the bottom may be readily removed BUSINESS METHODS 327 for cleaning purposes. The casing shall fit snugly around the sides of the radiators in order that the cold air shall pass between the surfaces instead of around them. The cold-air ducts will be made of galvanized iron and provided with a suitable damper and will be of such sizes as are necessary to supply the proper amount of cold air to the radiators. The hot-air duct shall be connected from the top of the casing to the register boxing in floor above. 20. Registers and Register Boxes. All registers shall be of design. The area of the openings in same will not be less than the area of the warm-air duct. Registers will be set firmly in the wall or floor and flush with the same. Register boxes made of bright I. C. tin shall be provided for each of the register openings. (The clauses 17, 18, 19 and 20 should be omitted, except where direct-indirect or indirect radiators are specified in a contract.) 21. In General. The material used in the construction of this apparatus shall be new and of the best quality and the work put up by skilled workmen. When the apparatus is completed it will be fired up and tested in the presence of the owner or his repre- sentative and left in good order ready for use. 22. Guaranty. I guarantee this work in every respect, that when completed it shall be free from mechanical defects and noise- less in operation, and that after the apparatus shall have been accepted by the owner, any part thereof shall fail to accomplish the guaranty herein contained by reason of any defect due to my workmanship or the materials furnished, I agree to remedy such defects at once at my expense. It is understood that the term " defect " as above used shall not be construed as embracing such imperfections as would naturally follow improper treatment, accident, or the wear and tear of use. 23. Bid. I agree to furnish the material herein specified and do the work as herein enumerated for the sum of Nine Hundred and Ninety-one Dollars and fifty-two cents ($991.52). Payments to be made as follows : One third when boiler is erected and material delivered on the job, one third when radia- tors are delivered and connected to the system, and the remain- ing one third after job shall have been completed and tested. (Signed) JOHN H. JONES. 328 PRACTICAL HEATING AND VENTILATION 24. Acceptance. To JOHN H. JONES, Heating Contractor. I hereby accept your proposal and bid for installing a com- plete hot-water heating apparatus in my residence and for the same agree to pay you Nine Hundred and Ninety-one Dollars and fifty-two cents ($991.52). Payments to be made as above specified. (Date) (Signed) R. D. BLANK. Special Features of Contracts Should there be any special materials or extra work de- manded, each additional item should be made the subject of a special paragraph and incorporated in the specifications. The following include some such items as might be necessary: Radiator boards, Temporary use of apparatus (charge for same), Coil in heater or boiler for heating water for domestic use, Domestic water supply where a tank with steam coil in same is provided for use with a steam boiler. There should also be figured such " extras " on the work, as additional charges for low radiators, peculiar decoration of radiators, etc., etc. Again, it is customary for some contractors to insert a clause in the specifications relative to the construc- tion of the building. For example, if it should be afterwards discovered that the plans of the job or the building to be heated or the information respecting same, which had been received from the owner or his representative, did not conform to the building or plans of same as figured, the heating contractor charges for any alterations occasioned by such misrepresenta- tion as an " extra." Some heating contractors desire to insert a paragraph in the specifications to the effect that if when the work is partially finished or, nearly completed, delay shall arise, due to no fault of the heating contractor, he shall be entitled to receive settlement, the same as though the work was entirely completed, except that a certain percentage is allowed to be withheld pending the actual completion of the job. Matters of the above kind are sure to arise on heating contracts and it is well to make mention of the same in the specifications in cases where the heating contractor considers it essential. CHAPTER XXVII MISCELLANEOUS Care of Heating Apparatus THE life and efficiency of a steam or hot water heating appa- ratus of whatever nature depend largely upon the care and at- tention given it, both when in service and during the summer period when the apparatus is not in use. Summer Care It is when the apparatus is inoperative that the greatest dam- age to it is wrought by disintegration due to rust and the chemical action of soot and ashes. It is, therefore, a good plan as soon as the season for artificial heating is past and the fire is allowed to go out in the heater, to thoroughly clean the grate and ash pit of all ashes. Remove the casing of the heater, if of portable construction. If not so provided, open all clean-out doors and thoroughly clean all heating and flue surfaces with a steel brush. Remove the smoke connection and clean it in a thorough manner. Find a dry place in which to store the smoke pipe for the sum- mer. Open all doors of the heater clean-out, fire and draught doors and allow them to remain open until the fire is again built in the heater. There has been much discussion, pro and con, as to the advisability of emptying the steam boiler or the hot-water heating apparatus during the summer season. Many engineers and heater manufacturers contend that the apparatus should be left full of water; others affirming just as positively that it should not be. Our own opinion, based upon our personal experience together with that of others, is that it is well to empty the system and free it of all moisture. We advocate the following procedure : Open the draw-off connection to the sewer, or with the use of pails drain all water from the boiler or system. Open all air 329 330 PRACTICAL HEATING AND VENTILATION vents and valves in order that none of the water may be entrained in the piping or radiators. Then build a light wood fire in the heater and evaporate all remaining water and moisture from the system, allowing all valves and air vents to remain open until the time has arrived when the use of the apparatus is again necessary, when the boiler or system can be refilled with fresh water. By following the directions given the inner surfaces of the apparatus may rust slightly, but will not scale and the bronzing or other decoration of radiators and piping will retain its luster for a longer period of time. Proper Attention to Boilers There are some few r rules regarding the proper attention to a steam boiler or hot-water heater which should be followed in order to escape possible damage to the heater and at the same time obtain good results from the use of the apparatus. Manu- facturers of heaters, as a rule, furnish each customer with direc- tions for the care and operation of every heater sold by them. There are, however, some few instructions which it may be well to repeat. To put the apparatus in condition for service, pro- ceed as follows. (We assume that the directions for summer care have been followed.) Put the smoke connection in position and see that the damper in the same works freely. Replace all fixtures, which may have previously been removed, in their proper positions. Refill the apparatus with water. If a steam boiler, it should be refilled to such an extent that the gauge on the water column stands about one half full of water. If a hot-water apparatus, the sys- tem should be refilled to such an extent that the gauge glass on the expansion tank stands about one quarter full of water. With a key suitable for the purpose, open each one of the air valves, using a small cup to catch any water that may flow out. Go over the entire system, freeing each radiator of all air. Now examine the gauge on the expansion tank and in all probability you W T J11 discover that it is necessary to turn more water into the system. If a steam apparatus, see that the damper MISCELLANEOUS 331 regulator is properly connected to draught and check doors and try the safety valve to insure its working freely. The apparatus is now ready for the season's service. In building the first fire, note w T ith care that the grate is thor- oughly covered with wood before putting on any coal in order that no unburnt coal will fall down on the grate and thereby deaden the fire. Add a quantity of coal from time to time until there is a deep clean fire in the heater. Endeavor to keep it in this condition while the apparatus is in use, remembering that there is no economy in a shallow fire and that a heater fire pot partially filled with ashes or the grate with unburnt coal will not give proper results. The ashes should be removed daily to pre- vent the possible burning out or warping of the grate. Should the w r ater in a steam boiler become low through acci- dent or . neglect, do not refill the apparatus until the fire has been drawn and the boiler castings allowed to cool. With some of those boilers constructed with a water base, this course is not absolutely necessary, although it is the safer plan to pursue. As long as any water shows in the gauge glass of a steam boiler, fresh water may be supplied with safety. Clean all heating and flue surfaces of soot at least once each week. Soot is a great non-conductor of heat and the boilers whose surfaces are allowed to remain coated with soot, require more attention and consume a greater amount of fuel than those in which the surfaces are kept thoroughly clean from all accu- mulation of such dirt. Steel wire brushes are made for this pur- pose and with their proper use a satisfactory cleaning of the heating surfaces can be obtained. Should a building remain unoccupied during cold weather, cr should it be closed temporarily in winter, all water should be drawn off and evaporated from the system in order to offset a possible danger from freezing. Removing Oil and Dirt In all new heating systems there is more or less oil and dirt present. The oil from machined castings, radiator tappings and pipe threading will work down into the boiler as will also particles of core sand from the radiator and boiler castings. The oil with PRACTICAL HEATING AND VENTILATION considerable dirt forms a scum on the surface of the water in the boiler, causing it to foam and at the same time preventing the generation of steam. This action frequently produces an un- steady water-line and hinders the proper working of the apparatus. The remedy for this condition is to blow off the boiler while under pressure. This should be done several times at intervals of a week or more until the oil has been thoroughly removed. To successfully blow off a steam boiler, close all radiator valves and build a good wood fire in the heater, generating a pressure of from ten to fifteen pounds. Open the blow-off valve and let the pressure of the steam blow all water out of the boiler. With it this water will carry most of the dirt and the greasy scum or oil. Allow the fire to burn out and the castings to cool, after which the boiler can be again refilled and the fire started. The blow-off is usually located at the bottom and rear of the boiler and as much of the oil will adhere to the inner surfaces of the boiler, as the w T ater settles or is forced out, it is often necessary to repeat this cleaning operation several times. Some manufacturers of sectional boilers, recognizing the ex- tent of the trouble due to the presence of oil, have provided their boilers with a blow-off located at the rear a few inches below the water line. Where such an opening is furnished, the scum and oil are readily blown out from the surface of the water, the ac- cumulation of dirt being removed through the draw-off cock at the bottom of the boiler. The blow-off opening should be at least l 1 /^" in diameter, and a still larger opening is preferable. Such a provision is styled a " surface blow-off " by some fitters and engineers. Summer Tests to Determine Efficiency Although the fact is not generally recognized by the con- tracting fitter, a heating apparatus may be tested as to its effi- ciency on a warm summer's day as well as in midwinter. Prof. R. C. Carpenter has laid down a rule which the writer has for some years followed in actual practice and we can, therefore, testify and vouch to the correctness of it. The table given shows in Column Four (Resulting Temperature of Room) the tempera- MISCELLANEOUS 333 tures which a room would have for various degrees of heat out- side, provided the radiation placed was sufficient to warm the room to 70 in zero weather with three pourfds pressure of steam or temperature. TABLE XXVIII Temperature Outside Air. Coefficient Heat per Square Foot per Hour per Degree. Total Heat per Square Foot per Hour. Resulting Tem- perature of Room. Difference Tem- perature Radia- tor and Room. -10 1.85 288 64.7 155.3 1.8 270 70 150 10 1.75 253 75.1 144.9 20 1.7 236 81 139 30 1.65 218 86.5 133.5 40 .6 203 93.1 128 50 .55 188 98.7 122.5 60 .5 172 104.7 116.5 70 .45 158 110.5 109.5 80 .4 142 117.1 102.9 90 1.35 130.5 123.5 96.5 100 1.3 117 130.3 89.7 Example showing application of Table: To determine by a test of the apparatus, when weather is 60, whether a guaranty to heat to 70 in zero weather is maintained, operate the apparatus as though in regular use and note the average temperature of the room. If the room has a temperature equal to or in excess of 104.7 F., it would have a temperature of 70 in zero weather, all other conditions, such as wind, position of windows, etc., being the same as on the day of the test. Care of Tools In order to perform good work rapidly it is necessary to have serviceable and sharp tools, particularly wrenches and those for pipe cutting and threading. Judging from the author's personal experience the old axiom " A workman is known by his tools " was apparently never intended to apply to a journeyman steam fitter for, as a class, the ordinary steam fitter can break, mutilate or otherwise destroy the efficiency of a tool quicker and with more reckless abandon than any other tradesman we have ever come in contact with in spite of the fact that there is absolutely no other trade where good and sharp tools are more necessary for efficient 334 PRACTICAL HEATING AND VENTILATION and rapid work than that of pipe fitting. There are some shop rules governing the care and use of tools which might be adopted by all heating contractors to good advantage. First, a complete kit of tools should be furnished each jour- neyman fitter and he should be charged with and held personally responsible for them and their condition. A steam fitter cannot be expected to make good time on work when he is furnished with wrenches that will not " bite " nor take proper hold of a pipe until after possibly three or four trials. Neither can good, clean threads be cut with dull or imperfect dies. For the reasons given these tools should have frequent and careful scrutiny by the master fitter or his shop boss. Second, the fitter should be instructed to allow his helper to spend the last fifteen or thirty minutes of each working day in gathering together and cleaning all tools which have been in use and all broken or dulled tools should be promptly returned to the shop. It is well to have a tool chest for each individual kit of tools. Iron chests, made for this purpose, are models of con- venience. To a contractor doing any considerable amount of work a pipe-cutting and threading machine will pay for itself in the labor saved on one or two fair-sized jobs. It is well to have one large machine for shop use and one or more portable machines cut- ting and threading up to 4" for use on the job. Labor Saving Suggestions There are some methods of saving time and money on contract work which are worthy of consideration. Do not allow the fitter to do the unskilled work of a laborer. Large pipe should be handled by laborers and the radiation on a job should be car- ried into and distributed throughout the building by the teamster and one or two laborers under the direction of the fitter or in accordance with an itemized list furnished the driver. Do not allow the cutting off of a short piece of pipe without first threading one end of it. These short pieces of pipe may then be returned to the shop and the other end of each piece threaded by a helper or unskilled workman. We have found it excellent practice to send to each job a MISCELLANEOUS 335 box each of short pieces of pipe in sizes 1", 1%" and l 1 /^" with both ends threaded. These may be laid out on the basement floor in a place conveniently near to the pipe vise, to be quickly measured and used by the fitter in order to save the cutting of short measurements. As soon as the vise and bench are in position the helper should arrange all fittings on the floor in rows according to their sizes and in such a place near the vise that they can be reached rapidly by the fitter. A pad of paper on which to make memoranda of measures or supplies needed from the shop should be tacked up close to the work bench. We would urge the advisability of making plans of all work, plans which will show in a general way the sizes of pipe and fittings and the method of running same and the manner of making the different connections. Such plans should be ad- hered to by the fitter as closely as the conditions of the work will permit. Adopt a system for handling all work and the results will show time and labor saved and increased profits accruing from the contracts. Bronzing, Painting and Decoration There are some few facts relating to the bronzing or paint- ing of radiators or radiating surfaces of a heating plant which the steam fitter should be fully posted on and thoroughly un- derstand. It is well to give all direct radiators or exposed pip- ing above the basement a priming coat of paint before applying the bronze, as the bronze will then cover more surface, look brighter and retain its luster for a longer period of time. Where gold bronze is to be used, a priming coat of yellow ochre is the best to apply; where aluminum bronze is made use of the priming coat should be white. If color bronzes are desired, the priming coats should conform as nearly as possible to the tints of the bronze. The priming coat should not contain oil of any kind, but should be mixed with japan and turpentine. One pound of gold bronze will cover 150 ft. of iron sur- face not primed and 200 ft. of primed surface. Each four pounds of gold bronze requires one gallon of liquid. As one pound of aluminum bronze powder is more than twice 336 PRACTICAL HEATING AND VENTILATION as bulky as gold bronze, it will cover more than double the sur- face, the amount varying from 350 to 400 ft. of surface. Uncovered basement piping should be painted with black japan or asphaltum varnish. In painting the piping in greenhouses, do not use tar paint , or asphaltum, as the odor or fumes given off, when heated, vrlll injure the plants. The best policy is to leave unpainted all greenhouse piping. However, in case it is necessary, use lamp- black mixed with turpentine and a very little boiled linseed oil. In mixing colors to harmonize with other decorations, the following table w r ill prove useful as a guide. The first color named in each combination is the base or predominant shade. Re- member to use only japan and turpentine in your mixing. Gray: Use white lead and lampblack. Buff: Use white lead, yellow ochre and red. Orange: Use yellow and red. Snuff: Use yellow and Vandyke brown. Pearl: Use white, black and blue. Drab: Use white, raw and burnt umber; or white, yellow ochre, red and black. Fawn: Use white, yellow and red. Flesh: Use white, yellow ochre and vermilion. Gold: Use white, stone ochre and red. Copper: Use red, yellow and black. Lemon: Use white and yellow. Pea Green: Use white and chrome green. Bronze-Green: Use chrome green, black and yellow; or white, yellow ochre, red and black. In tinting use nearly as much of the base or first-named color, as is desired and tint with the following named or supplementary colors. Colored enameled paints for the decoration of radiators may be procured. However, we advise against their use, as they tend to subtract from the efficiency of the radiating surfaces by filling, and sealing the pores of the iron, thus making necessary a larger amount of heating surface than would otherwise be required. Care should be taken to remove all oil or grease from the surfaces to be painted or bronzed. MISCELLANEOUS 337 Guaranty It may not be amiss to make mention of and comment on the above term as used verbally or written in contracts by the heat- ing contractor. While, no doubt, the man who is doing honest and conscientious work, figuring a sufficiency of radiation and plenty of boiler power, has little to fear from the employment of this word, there are occasions where it becomes unwise to make use of it in a heating contract. In contracts for heating work we have noted many times the words " I guarantee satisfaction," or " I guarantee to give you a satisfactory job." This word " satisfaction " employed in this connection is apt to prove a troublesome one and a contractor is making a great mistake when he incorporates it in a heating contract. He may be perfectly honest in his intentions to give the owner a "satisfactory" job and may go to extremes in his endeavors to do perfect work and satisfy the owner. However, it leaves a loophole for the sharp and unscrupulous man to crawl into and although the job may be perfect in its working and effectiveness he may withhold payment for it indefinitely on the plea that he is not satisfied. If a guaranty is included, it should be carefully worded to cover certain specific things. A certain temperature in each room in which radiation is placed, a workmanlike job, a boiler or heater to be of sufficient size to do the work easily, all or any one of these conditions may be safely guaranteed by the con- tractor who does good work. Architects, unwisely, frequently draw up specifications in which certain conditions are set forth and the heating contractor is requested to sign a contract of which these specifications become a part. He should refuse to affix his name to them until all the circumstances are clearly stated. Commercially the clause " 70 in zero weather " implies that the apparatus must be of sufficient size to heat a certain build- ing in which it is placed to this degree when the prevailing tem- perature outside the building stands at zero. In many sections of this country in which artificial heat is required, the ther- mometer may not register a zero weather temperature once in five years or more, and therefore should the architect or owner 338 PRACTICAL HEATING AND VENTILATION resort to unprincipled practice the heating contractor would be compelled to wait an indefinite time for payment. As stated in a former chapter of this book, Prof. Carpenter has given a very good and accurate rule for summer or warm weather tests and where a 70 clause is inserted in a contract, there should be a reference made to this or some other equally good rule governing a test which will be acceptable alike to owner and contractor. Quite frequently we find an architect or owner who requires the heating contractor to give a bond that the apparatus when completed will perform a certain work. Where a bond of this nature is insisted upon, the contractor should be paid in full the moment his work is finished. We have always regarded the fur- nishing of a bond as tending to operate against the best interests of the owner. In his anxiety to have the work completed at as low a price as possible, he may accept the low bid of a con- tractor without responsibility or reputation, require a bond from him and save a few dollars on the original cost of the contract. When difficulty arises, as is quite likely in such cases, and it becomes necessary to bring suit, the expenses incident to such action more than offset the amount originally saved and the owner has the further trouble, discomfort and expense of the tem- porary maintenance of an unsatisfactory job. Had the work been awarded to a contractor of experience and reputation no such trouble would be experienced. It would seem that the over-anxiety of some heating con- tractors to secure work is largely responsible for many of the conditions we have enumerated. In some instances they seem willing to agree to anything or to sign any document in order to obtain a contract, and this of itself should furnish a danger signal to both architect and owner, as the responsible man will not affix his name or agree to anything which he cannot con- sistently perform, or which is against his best interests. In examining the contracts of some heating contractors of large experience, we find some clauses included which are well worth our consideration. In connection with the " Acceptance " clause we find the following: " Upon notification from us that the work herein specified is MISCELLANEOUS 339 complete, it shall be promptly inspected and accepted or rejected, so that our man, while still on the premises, may, without delay, complete it or remedy any defect that may appear, after which you are to give said man written acceptance of the work herein specified, it being agreed that such acceptance is not a waiver of our guaranties. " If not inspected immediately on completion, the apparatus will be left in your charge, and our responsibility for it ceases. " Failure to so promptly inspect and accept or reject said work shall be construed as an acceptance of it, and shall entitle us to payment according to contract." Or this: " The apparatus, in so far as the mechanical work thereof and the construction of the same are concerned, shall be considered as accepted immediately upon completion. If it be found that the same does not comply with said specifications, notice thereof shall be given in writing immediately to the heating contractor. " It is distinctly understood that no payments or part thereof are to be delayed on account of lack of cold weather in which to test the heating apparatus, as the guaranty herein contained is binding upon the heating contractor as to the fulfillment of the contract. It is further understood that such acceptance shall not be deemed a waiver of our guaranty as to efficiency of the heat- ing apparatus." As to the forms of guaranties, we have given in the chapter on " Business Methods " a short concise form. Some others, which in certain cases cover more of the detail of the work, are as follows : (a) " We hereby guarantee that the apparatus shall be noise- less in operation, of ample capacity and, under proper conditions of firing and management, to be capable of warming all rooms in which radiators are placed to degrees in coldest weather. (6) " The apparatus is guaranteed for a period of one year from this date against any defects of workmanship or materials. Should any defect or deficiency develop, we will, upon notice, make good such defect or deficiency at our expense:" Or this : " When the apparatus herein proposed to be furnished is 340 PRACTICAL HEATING AND VENTILATION completed in accordance with the conditions hereof, we guarantee that it will be so constructed as to permit steam to circulate in all its parts with - - pressure thereon, or any higher pressure ; and that the said apparatus shall be capable of continuously warm- ing all parts of said building that are enumerated in Section 8 of this proposal (schedule of radiation and temperatures) to the temperature mentioned therein when the outside temperature is degrees below zero ; further, the buildings and apparatus being kept in repair, and the apparatus properly operated, there shall be no snapping, cracking or pounding in the piping or radiators. We further guarantee all materials furnished shall be free from all defects for a period of one year from the date of this instrument." Several of the guaranties examined contain this or a similar clause : " The chimney furnished by the owner shall be large enough to be capable of passing sufficient air to insure rapid combustion of fuel. We will not be responsible for failure of apparatus due to insufficient draught." A steam or hot-water heating apparatus or a ventilating apparatus is designed to secure certain results under certain given conditions and these should be clearly stated in and be made the subject matter of all conditions and guaranties of a contract. Boiler Explosions The danger arising from the explosion of a low-pressure cast-iron steam or hot-water heater is very remote, yet it is a feature which causes fear in the mind of every nervous person whose duty it is to attend to such a heater or to be in any manner brought into close contact with it. While it is a fact that many boilers explode, the percentage is small, even consider- ing the vast number of boilers used for generating steam for power purposes as well as for heating. There is no question but that excess of pressure is the cause of all explosions ; we mean by this, excess over the ability of the boiler to stand. For in- stance, a boiler may be built originally to withstand a pressure of 250 pounds, but through frequent scaling, or from rupture, or some other damaging cause, may become weakened to such an MISCELLANEOUS 341 extent that 100 Ibs. would be an excess of pressure for it to carry with safety. Low water in such a boiler, with the consequent rapid vapor- izing into steam, due to a hot fire, would cause it to explode, and were the explosion to occur instantly it would be accom- panied with disastrous results. If, on the contrary, there were a gradual tearing of the iron at the weak point or gradual open- ing of the rupture, no very great damage might occur. Most of the disastrous explosions of heating boilers have occurred where boilers of the tubular (vertical or horizontal) or fire-box type were used and but few have happened with cast-iron boilers. There are many theories as to the causes of boiler explosions, and when applied to boilers employed for warming, the principal one seems to be that the explosion is caused by admitting cold water into red-hot boilers. When for some unaccountable reason the boiler has been drained or the water in it lowered well below the crown-sheet surface, the sudden admission of a quantity of cold water will cause trouble; not necessarily an explosion, for we do not believe this would be the result once in ten times. If a cast-iron boiler, the sections would undoubtedly crack; if a wrought-iron boiler, a rupturing of the plates and riveting would likely result, requiring in either case extensive repairs. We have alluded especially to steam boilers as being liable to explode under certain conditions, but, as a matter of fact, the most dangerous explosions of heating apparatus might occur with a hot-water system. The pent-up or stored energy in a hot-water apparatus is very much greater than that from steam at an equal volume. The sudden releasing of this force, due to a break in the apparatus, is liable to cause great damage, including a possible loss of life. Prevention of Explosions In the operation of a steam-heating apparatus only ordinary caution is necessary to prevent a rupture or explosion of the boiler, provided the usual safeguards are furnished with the ap- paratus. These safeguards are, first, a safety valve of adequate size, kept operative by frequent testing; second, the providing of PRACTICAL HEATING AND VENTILATION a fusible plug, which should be placed at a point just below the low water-line of the boiler, that is, the lowest level at which the water may stand with safety ; third, the provision of a sediment cock at a low point, where sediment (mud, sand, etc.) may be frequently drawn from the boiler. Should valves be placed on the flow and return pipes at the boiler, they must be used with caution. Never entirely close the valves on the steam main without checking and thereby cooling the fire. Never close all valves on the return pipes while the valves on steam-supply pipes are open, or when heat is on the building. We have known cases where a slothful janitor left the valves on the returns closed, with the result that the rapid condensing of the steam and collection of the condensation in the returns low- ered the water in the boiler below the level of safety. When this condition occurs, or should the water become low from any other cause, do not open the valves on the returns and admit the water of condensation, which has cooled, and do not admit any other supply of cold water until, as a precautionary measure, the fire has been dampened or drawn and the boiler allowed to cool for two hours. In operating a hot-water heating apparatus but few precau- tions are necessary, provided the contractor in erecting the work has exercised due care. There should be no valves placed on the expansion-tank connections. The tank should be placed in a warm room in order that these connections will not freeze. If of necessity the tank must be located in a cold spot, it should be circulated in a manner illustrated in a previous chapter of this book, in order to prevent freezing. With the tank open to the atmosphere the attendant of a hot-water boiler may feel ab- solutely safe as far as any danger or damage from explosion is concerned. Utilizing Waste Heat Wasted heat units in the process of heating or manufacturing often represent an expense for fuel, which, if saved, would ma- terially lessen the cost of production and add to the profits of the business. Many of our readers are no doubt more or less familiar with the old methods of heating dryers, dry kilns, etc., by the use of steam coils. MISCELLANEOUS 343 The waste of heat in an ordinary heating apparatus, due to poor draught or an imperfect chimney, we have commented upon and shown the advantages and saving accruing from perfect com- bustion and a properly constructed chimney. We have also shown the benefit resulting from the use of the exhaust steam from engines, pumps, etc. In this chapter we wish to make mention of the saving effected by a proper use of fans. The trouble encountered in using the old style of dryer and heat from steam coils was principally due to the slow and often uncertain movement of the air in the dryer. In drying lumber, bricks and pottery the circulation of air is as important as the heat provided. The same is true regarding the drying of manu- factured wooden articles, of laundry and all the various woolen and cotton products. High temperatures are maintained in the dry-room or kiln and under the original methods of drying by steam the hotter the dry-room the quicker and the cheaper the desired results could be obtained. The character of the work, that is to say, the nature of the material to be dried and the temperature necessary to be main- tained govern the method of installing the apparatus. There are two general methods of utilizing waste heat for this purpose, the first, the utilizing of exhaust steam in heating coils within the dryer, air being forced into and through it by a pulley-driven fan located at one end of the dryer. The second is that which is adapted for the drying of bricks or pottery, where the waste heat from cooling kilns is drawn through ducts to a fan, which in turn delivers it, in such quantities as desired, to the dryer. An exhaust fan is located at the opposite end of the dryer to facilitate the movement of the air. To illustrate this method we have chosen the apparatus as designed by the New York Blower Company and show by Fig. 303 an elevation plan and by Fig. 304 a ground-floor plan of the same. There are so many adaptations of this method that it is not convenient to illustrate or discuss all of them. When no waste heat is available, an ordinary type of pipe heater may be used with a blower fan and exhaust steam used in the heater. On many jobs a large proportion of the heat units from the 344 PRACTICAL HEATING AND VENTILATION MISCELLANEOUS 345 coal consumed will be lost in the chimney flue, the amount of loss being dependent on the character of the boiler, as some boilers COMBINATION WASTE HEAT STEAM AND FURNACE BRICK DRYER DAMPER^jj KILN FIG. 304. Ground-floor plan waste-heat utilizer. have more of a direct draught than others and consequently lose more of the heat units from the fuel consumed. It is true that PRACTICAL HEATING AND VENTILATION a certain percentage of this loss is necessary the chimney must be provided with sufficient heat to expand the air in the flue and to produce sufficient draught in the same. There are several methods of utilizing the heat units ordi- narily wasted in this manner. The hot smoke and gases may be passed through the flues of a cylindrical jacket or water heater, thus warming a sufficient quantity of water for domestic pur- poses. Again, they may pass through a supplementary casing under the ordinary type of hot-water storage tank, the smoke and gases entering this compartment at one end of the tank and leaving the compartment at the opposite end. It is a fact in heating practice that the hotter the return water, the more easily it is reheated by the boiler and circulated, if a hot-water appa- ratus, or generated into steam, if a steam-heating apparatus. The smoke and hot gases usually wasted may be utilized in heating the return water on a steam job by returning the con- densation through a heater having large flues through which the hot gases pass en route to the chimney, thus adding to the capac- ity of the boiler and accomplishing at the same time a material saving in fuel. While to a certain extent mechanical methods of drying and utilizing waste heat, or the reheating of return w r ater, have no particular bearing on general steam-fitting practice, it is well to become familiar with the various methods employed in this direc- tion. CHAPTER XXVIII Rules, Tables, and Other Information THE author has selected the following information and tables from a large mass of data gathered from all reliable sources, as being of value to the steam fitter and heating contractor. While we cannot in every case guarantee the correctness of the data given, we believe all the information to be fully reliable, as it has been compiled from standard authorities and by men of practical experience. As we have previously remarked in the pages of this book, there is no rule but what must be applied with judgment, as existing conditions necessarily govern its application. Where this care is exercised the information given will prove of very great value and assistance to the practical steam fitter. Rules, Tables, and Useful Information A U. S. gallon weighs 8.331 Ibs. and contains 231 cubic inches or .13667 cubic feet. 224 gallons of pure water weigh one ton ; 13.44 gallons weigh 100 Ibs. A cubic foot of water at a temperature of 32 Fahr. weighs 62.418 Ibs.; at 212 Fahr. it weighs 59.76 Ibs. The expansion of water from 32 Fahr. (freezing) to 212 Fahr. (boiling) is one gallon in each twenty-three, or approxi- mately k\%. Water boils in vacuum at 98 Fahr, at sea level at 212 Fahr. 347 348 PRACTICAL HEATING AND VENTILATION In figuring weight of water its bulk or quantity is considered. In determining pressure, the height of its column (vertical) is figured, approximately l/^ Ib. for each foot of height. A column of water one foot high equals a pressure of .433 Ib. per square inch. A pressure of 1 Ib. per square inch equals 2.31 feet of water in height. Water transformed into steam expands 1,700 times its vol- ume. One cubic inch of water will produce approximately one cubic foot of steam. A pound of anthracite coal contains about 14,500 heat units. A bushel of anthracite coal weighs about 86 Ibs. A ton of anthracite contains about 40 cubic feet. A bushel of bituminous coal weighs about 76 Ibs. A ton of bituminous contains about 49 cubic feet. The average consumption of fuel in a power boiler is 7% pounds of coal or 15 pounds of dry pine wood for each cubic foot of water evaporated. One square foot of grate (tubular boiler) will with natural draught consume 12 pounds of anthracite or 20 pounds of bitu- minous coal per hour. Double this amount can be burned with forced draught. Each nominal Horse Power in a tubular boiler requires 1 cubic foot of water per hour. RULES, TABLES, AND OTHER INFORMATION 349 Condensing engines require from 20 to 25 gallons of water to condense the steam from one gallon of water. In calculating Horse Power of tubular or flue boilers, 15 square feet of heating surface is equivalent to one nominal Horse Power. The specific gravity of steam at atmospheric pressure is .411 that of air at 34 Fahr., and .0006 that of water at the same temperature. To determine necessary surface in square feet for aspirating coil in ventilating flue, divide the cubic feet of air to be moved per hour by .95 when steam is used, or .60 when hot water. To find capacity of expansion tank required, multiply the square feet of radiation by .03 if less than 1,000 sq. ft. Mul- tiply by .025 between 1,000 and 2,000 sq. ft. and by .02 if more than 2,000 sq. ft. The result will be the size in gallons. To find the length of pipe required when making an offset with 45 fittings, a simple rule is as follows: For each inch of offset add if of an inch and the result will be the center-to- center measurement of the 45 angle. Twelve pounds of air are required to supply oxygen enough to burn one pound of coal. Perfectly dry air expands one-four-hundred-ninetieth (1/490) of its volume when heated from 32 degrees to 190 degrees. When saturated with vapor it expands nearly four times its former volume. The velocity of hot air from a furnace is approximately 10 feet per second at the register, with ordinarily good circulation. To find the circumference of a circle multiply the diameter by 3.1414 or by 8*. 350 PRACTICAL HEATING AND VENTILATION To find diameter of circle, multiply the circumference by 0.3183. To find the area of a circle multiply .7854 by the square of the diameter, that is, by the diameter multiplied by itself. Cement for Steam Boilers: Red or white lead in oil four parts, iron borings three parts, makes a soft cement. Cement for Leaky Boilers: A cement for leaky boilers (steam or hot water) consists of two parts powdered litharge, two parts of fine sand and one part of slacked lime. Mix with linseed oil and apply quickly. Rule for Calculating Speed and Size of Pulleys To Find the Size of Driving Pulley: Multiply the diameter of the driven by the number of revolutions it shall make and divide the answer by the revolutions of the driver per minute. The answer will be the diameter of the driver. To Find the Diameter of the Driven That Shall Make a Given Number of Revolutions: Multiply the diameter of the driver by its number of revolutions and divide the answer by the number of revolutions of the driven. The answer will be the diameter of the driven. To Find the Number of Revolutions of the Driven Pulley: Multiply the diameter of the driver by its number of revolutions and divide by the diameter of the driven. The answer will be the number of revolutions of the driven. When it is not convenient to measure with the tape line the length required, apply the following rule : Add the diameter of the two pulleys together, divide the result by , and multiply the RULES, TABLES, AND OTHER INFORMATION 351 quotient by 3%, then add this product to twice the distance be- tween the centers of the shafts, and you have the length required. The working adhesion of a belt to the pulley will be in pro- portion both to the number of square inches of belt contact with the surface of the pulley and also to the arc of the circumference of the pulley touched by the belt. This adhesion forms the basis of all right calculation in ascertaining the width of belt necessary to transmit a given horse power. TABLE XXIX GAUGES AND THEIR EQUIVALENTS No. 27, equal to ^ 4 - inch. No. 12, equal to -& inch. No. 21, equal to fa inch. No. 10, equal to inch. No. 18, equal to j 4 inch. No. 8, equal to H inch. No. 16, equal to iV inch. No. 6, equal to fa inch. No. 14, equal to ft inch. No. 5, equal to fa inch. No. 13, equal to fa inch. No. 4, equal to i inch. To Find Expansion of Pipe: Deduct the temperature of pipe at time of installation from the maximum temperature to which it will be heated, take -fy of this difference and divide by 100. The result will equal the expansion in inches for each 100 lineal feet of pipe. To Determine the Capacity of a Cylinder or Round Tank in Gallons: Multiply the diameter in inches by itself, this by the height in inches, and the result by 24. Another rule is to multiply the square of the diameter in feet by 0.7854 and this by the depth in feet. This result multiplied by 7.476 will give the capacity in gallons. To Clean Brass: Mix in a stone jar one part of nitric acid, and one half part of sulphuric acid. Dip the brass into this mix- ture, wash in water, and dry in sawdust. If greasy, first clean the brass by dipping in a strong mixture of potash, soda, and water, and wash thoroughly in water. 352 PRACTICAL HEATING AND VENTILATION To Remove Stains from Marble: Mix two parts of soda, one of ground pumice, and one of finely-powdered chalk. Sift through a fine sieve and with water mix into a paste. Rub this composi- tion on the marble and wash with soap and water. To Remove Grease Stains from Marble: Mix one and one half parts of soft soap, three parts of fuller's earth, and one and one half parts of potash with boiling water. Cover grease spots with this mixture and allow it to stand twenty-four hours, after which wash with hot water. To Remove Rust from Steel: Steel which has been rusted can be cleaned by brushing with a paste compound of % oz. cyanide of potassium, % oz. castile soap, 1 oz. whiting, and water sufficient to form a paste. The steel should be washed with a solution of 1/2 oz. cyanide of potassium in 2 oz. of water. To Prevent Machinery from Rusting: Take 1 oz. of camphor and dissolve in one pound of melted lard. Remove the scum and mix enough lamp-black to give an iron color. Clean the ma- chinery and smear it with the mixture. Under ordinary circum- stances it will not rust for months. To Harden Cast Iron: Cast iron can be hardened as easily as steel, and to such a degree of hardness that a file will not touch it. Take one half pint of vitriol, one peck of salt, one half pound of saltpetre, two pounds of alum, one quarter pound prussic potash, one quarter pound of cyanide of potash and dissolve in ten gallons of rain water. Stir until thoroughly dissolved. Heat the iron to a cherry red and dip it into the solution. If the iron needs to be very hard, reheat it and dip a second or a third time. To Inscribe Metal: Cover the part with melted beeswax; when cold, write what you desire plainly in the wax, taking care that the scriber cleans the wax from the metal. Then with a mixture RULES, TABLES, AND OTHER INFORMATION 353 of 1/2 oz. nitric acid and 1 oz. of muriatic acid carefully fill each letter of the inscription. For this service a feather will be found to be very adaptable. Let the acid remain for from one to ten minutes and then throw on water to arrest the action of the acid. Remove the wax by heating and the inscription will be completed. TABLE XXX MELTING POINTS OF METALS Tin , 446 Bismuth 507 Lead 617 Zinc 773 Antimony 810 Aluminum 1,400 Bronze 1,692 Silver 1,873 Brass 1,900 Copper 1,996 Gold 2,066 Glass 2,377 Steel 4,000 Cast iron 2,250 Wrought iron 2,912 Platinum. . 3,080 TABLE XXXI BOILING POINTS OF FLUIDS Water (Complete Vacuum) 98 Water (At Sea Level) 212 Alcohol 173 Sulphuric Acid 240 Refined Petroleum 316 Turpentine 315 Sulphur 570 Linseed Oil 597 Mercury (Atmospheric Pressure) . . 676 Ammonia 140 Coal Tar 325 Olive Oil 413 Sea Water (Average) 213 354 PRACTICAL HEATING AND VENTILATION TABLE XXXII TABLES OF WEIGHTS AND MEASUBES Liquid Measure 4 gills make 1 2 pints " 1 pint quart 4 quarts . . . . 31^ gallons.. make 1 gallon " 1 barrel Measures of Length 4 inches make 1 hand 5^ yards make rod or pole 7.92 1 link 40 poles furlong 18 " 1 cubit 8 furlongs " mile 12 " 1 foot 69y 6 miles " degree 6 feet 1 fathom 60 geographical miles " degree 3 " 1 yard 1,760 yards or. 5,280 feet " mile Measures of Surface 144 square inches make 1 square foot 9 square feet 1 square yard square yards 1 square rod 40 square rods 1 square rood 4 square roods 1 square acre 10 square chains 1 square acre 640 square acres 1 square mile Cubic Measures 1,728 cubic inches make 1 cubic foot 2,150 .42 cubic inches 1 bushel 46,656 cubic inches 1 cubic yard 7,276 . 5 cubic inches 1 barrel 27 cubic feet 1 cubic yard 128 cubic feet 1 cord 4 . 21 cubic feet 1 barrel Weight of Metals Lead 1 foot square, 1 inch thick, we ghs 59 . 06 pounds Copper 1 " " 1 " ' 45.3 Cast Iron 1 " " 1 " ' ' 37.54 " Wrought Iron 1 " " 1 " ' ' 40.5 Cast Steel 1 ' 1 40.83 Table of Weights (avoirdupois) 16 drams make 1 ounce (oz.) 16 ounces 1 pound (Ib.) 25 pounds 1 quarter (qr.) 4 quarters .- 1 hundred (cwt.) 20 cwt. or 2,000 Ibs 1 net ton The gross ton is 2,240 pounds. Weights, etc. One Cubic Inch of Cast Iron weighs .26 pound One Cubic Inch of Wrought Iron weighs . 28 pound One Cubic Inch of Water weighs .36 pound One United States Gallon weighs 8 .33 pounds One Imperial Gallon weighs 10 .00 pounds One United States Gallon equals 231 .00 cubic inches One Imperial Gallon equals 277 . 274 cubic inches One Cubic Foot of Water equals 7.48 U. S. gallons One Pound of Steam equals 27 .222 cubic feet One Pound of Air equals 13 .817 cubic feet RULES, TABLES, AND OTHER INFORMATION 355 TABLE XXXITI METRIC SYSTEM Prefixes of Multiples and Sub-Multiples of Meter, Liter, and Gram Deka =10 Deci =0.1 Hecto=100 Centi=0.01 Kilo =1000 MUli =0.001 10 millimeters =1 centimeter. 10 meters =1 dekameter. 10 centimeters = 1 decimeter. 10 dekameters = 1 hectometer. 10 decimeters =1 meter. 10 hectometers =1 kilometer. METRIC EQUIVALENTS Linear Measure 1 centimeter =0.3937 in. 1 in. =2.54 centimeters or 0.254 meter. 1 decimeter = 3 . 937 in. = . 328 ft. 1 ft. = 3 . 048 decimeters or . 3048 meter. 1 meter =39. 27 in. =1.0936 yards. 1 yard =0.9144 meter. 1 dekameter =1.9884 rods. 1 rod =0.5029 dekameter. 1 kilometer =0.62137 mile. 1 mile =1.6093 kilometers. Surface or Square Measure 1 sq. centimeter = 0.1550 sq. in. 1 sq. inch = 6.452 sq. centimeters. 1 sq. decimeter = 0.1076 sq. ft. 1 sq. foot = 9.2903 sq. decimeters. 1 sq. meter = 1,196 sq. yd. 1 sq. yard = 0.8361 sq. meter. 1 are = 3.954 sq. rods. 1 sq. rod = 0.2529 are. 1 hektar = 2.47 acres. 1 sq. acre = 0.4047 hektar. 1 sq. kilometer = 0.386 sq. mile. 1 sq. mile = 2.59 sq. kilometers. Measure of Volume and Capacity 1 cu. centimeter =0.061 cu. in. 1 cu. inch =16. 39 cu. centimeters. 1 cu. decimeter =0.0353 cu. ft. 1 cu. foot =28. 317 cu. decimeters. 1 cu. meter ) = j 1.308 cu. yards. 1 cu. yard =0.7646 cu. meter. 1 ster f (0.2759 cord. 1 cord =3.624 sters. 1 1't r = -i 908 c l uart dry- 1 quart dry = 1 . 101 liters. ( 1.0567 quarts liq. 1 quart liq. =0.9463 liter. 1 dekaliter 5 2.6417 gallons. 1 gallon =0.3785 dekaliter. ( .135 peck. 1 peck =0.881 dekaliter. 1 hectoliter =2. 8375 bushels. 1 bushel =0.3524 hectoliter. Weights 1 gram =0.0527 ounce. 1 ounce =28.35 grams. 1 kilogram =2. 2046 Ibs. 1 Ib. =0.4536 kilogram. 1 metric ton =1.1023 English tons. 1 English ton =0.9072 metric ton. a 35- [ill in 8-8 00-* 1-1 !-H C^r-Hr-lOJ>^' I rH ^ rH O* -* CD 9t 00 *Q O Q 9) t* i-i CO r-> rH r 1 rHQ* Ot-0^ rHGJrH 356 RULES, TABLES, AND OTHER INFORMATION 357 . TABLE XXXV COMPARISON OF THERMOMETRIC SCALES Fahr- enheit. Centi- grade. Reaumur. Fahr- enheit. Centi- grade. Reaumur. - 40 - 40.00 - 32.00 + 125 + 51.67 + 41.33 " 35 " 37.22 " 29.78 "130 " 54.44 " 43.56 " 30 " 34.44 " 27.56 "135 " 57.22 " 45.78 " 25 " 31.67 " 25.33 "140 " 60.00 " 48.00 " 20 " 28.89 " 23.11 "145 " 62.78 " 50.22 " 15 " 26.11 " 20.89 "150 " 65.55 " 52.44 " 10 " 23.33 " 18.67 "155 " 68.33 " 54.67 " 5 " 20.55 " 16.44 "160 " 71.11 " 56.89 " 17.78 " 14.22 "165 " 73.89 " 59.11 + 5 " 15.00 " 12.00 "170 " 76.67 " 61.33 " 10 " 12.22 " 9.78 " 175 " 79.44 " 63.56 " 15 " 9.44 " 7.56 "180 " 82.22 " 65.78 " 20 " 6.67 " 5.33 "185 " 85.00 " 68.00 " 25 " 3.89 " 3.11 "190 " 87.78 " 70.22 " 30 " 1.11 " 0.89 "195 " 90.55 " 72.44 " 32 0.0 0.00 "200 " 93.33 " 74.67 " 35 + 1.67 + 1.33 "205 " 96.11 " 76.89 " 40 " 4.44 " 3.56 "210 " 98.89 " 79.11 " 45 " 7.22 " 5.78 "212 "100.00 " 80.00 " 50 " 10.00 " 8.00 "250 "121.10 " 96.90 " 55 " 12.78 " 10.22 "300 "148.89 "119.20 " 60 " 15.55 " 12.44 "302 "150.00 "120.00 " 65 " 18.33 " 14.67 "350 "176.66 "141.40 " 70 " 21.11 " 16.89 "392 "200.00 "160.00 " 75 " 23.89 " 19.11 "464 "240.00 "192.00 " 80 " 26.67 " 21.33 "500 "260.00 "208.00 " 85 " 29.44 " 23.56 "572 "300.00 "240.00 " 90 " 32.22 " 25.78 "600 "315.06 "252.40 " 95 " 35.00 " 28.00 "662 "350.00 "280.00 "100 " 37.78 " 30.22 "700 "371.11 "296.90 "105 " 40.55 " 32.44 "752 "400.00 "320.00 "110 " 43.33 " 34.67 "800 "426.66 "341.30 " 115 " 46.11 " 36.89 "932 "500.00 "400.00 " 190 " 48 8Q " 39.11 1/U T!O . oy 358 PRACTICAL HEATING AND VENTILATION TABLE XXXVI TABLE OF THE AREAS OF CIRCLES AND OF THE SIDES OF SQUARES OF THE SAME AREA Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. Diam- eter of Circle in inches. Area of Circle in square inches. Sides of Sq. of same area in square inches. 1 .785 .89 21 346.36 18.61 41 1,320.26 36.34 Y* 1.767 1.33 Y 2 363.05 19.05 1 A 1,352.66 36.78 2 3.142 1.77 22 380 . 13 19.50 42 1,385.45 37.22 K 4.909 2.22 H 397.61 19.94 1 A 1,418.63 37.66 3 7.069 2.66 23 415.48 20.38 43 1,452.20 38.11 Y 2 9.621 3.10 H 433.74 20.83 H 1,486.17 38.55 4 12.566 3.54 24 452.39 21.27 44 1,520.53 38.99 1 A 15.904 3.99 Y2 471.44 21.71 H 1,555.29 39.44 5 19.635 4.43 25 490.88 22.16 45 1,590.43 39.88 1 A 23.758 4.87 H 510.71 22.60 1 A 1,625.97 40.32 6 28.274 5.32 26 530.93 23.04 46 1,661.91 40.77 1 A 33.183 5.76 H 551.55 23.49 1 A 1,698.23 41.21 7 38.485 6.20 27 572.56 23.93 47 1,734.95 41.65 1 A 44.179 6.65 H 593.96 24.37 1 A 1,772.06 42.10 8 50.266 7.09 28 615.75 24.81 48 ,809.56 42.58 1 A 56.745 7.53 Y2 637.94 25.26 H ,847.46 42.98 9 63.617 7.98 29 660.52 25.70 49 ,885.75 43.43 1 A 70.882 8.42 Y2 683.49 26.14 M ,924.43 43.87 10 78.540 8.86 30 706.86 26.59 50 ,963.50 44.31 y 2 86.590 9.30 Y 2 730.62 27.03 y 2 2,002.97 44.75 11 95.03 9.75 31 754.77 27.47 51 2,042.83 45.20 H 103.87 10.19 y 2 779.31 27.92 H 2,083.08 45.64 12 113.10 10.63 32 804.25 28.36 52 2,123.72 46.08 Y2 122.72 11.08 Y 2 829.58 28.80 Y2 2,164.76 46.53 13 132.73 11.52 33 855.30 29.25 53 2,206.19 46.97 Yz 143.14 11.96 Y2 881.41 29.69 Yz 2,248.01 47.41 14 153 . 94 12.41 34 907.92 30.13 54 2,290.23 47.86 Yz 165.13 12.85 Y 2 934.82 30.57 Y2 2,332.83 48.30 15 176.72 13.29 35 962.11 31.02 55 2,375.83 48.74 Yz 188.69 13.74 1 A 989.80 31.46 Y2 2,419.23 49.19 16 201.06 14.18 36 ,017.88 31.90 56 2,463.01 49.63 M 213.83 14.62 1 A ,046.35 32.35 H 2,507 . 19 50.07 17 226.98 15.07 37 ,075.21 32.79 57 2,551.76 50.51 H 240.53 15.51 H ,104.47 33.23 Y* 2,596.73 50.96 18 254.47 15.95 38 ,134.12 33.68 58 2,642.09 51.40 H 268.80 16.40 Yi ,164.16 34.12 M 2,687.84 51.84 19 283.53 16.84 39 ,194.59 34.56 59 2,733.98 52.29 Y2 298.65 17.28 Y2 ,225.42 35.01 Y2 2,780.51 52.73 20 314.16 17.72 40 ,256.64 35.45 60 2,827.74 53.17 Y2 330.06 18.17 H ,288.25 35.89 Y2 2,874.76 53.62 RULES, TABLES, AND OTHER INFORMATION 359 TABLE XXXVII TEMPERATURE OF STEAM AT VARIOUS PRESSURES ABOVE THAT OF THE ATMOSPHERE (14.7 LBS.) Pounds Pressure. Degrees Fahrenheit. Pounds Pressure. Degrees Fahrenheit. Pounds Pressure. Degrees Fahrenheit. 212 18 254.5 100 337.5 1 215.5 19 256 105 341 2 219 20 257.5 115 347 3 222 25 265 125 353 4 225 30 272.5 135 358 5 227.5 35 279.5 145 363 6 230 40 285.5 155 368 7 232.5 45 291 165 373 8 235 50 297 175 377 9 237.5 55 302 185 381 10 240 60 307 235 401 11 242 65 311 285 417 12 244 70 315 335 430 13 246 75 320 385 445 14 248 80 323 435 456 15 250 85 327 485 467 16 252 90 331 585 487 17 253.5 95 334 685 504 TABLE XXXVIII PROPERTIES OF SATURATED STEAM Pres- sure. Abso- lute Pres- sure. Tem- perature Fahren- heit. Total Heat above 32 degrees. Latent Heat. Relative Volume 39 =1. Volume C. F. in 1 Ib. Steam. Weight 1 cubic foot Steam. Lbs. Heat Units in the Water. Heat Units in the Steam. 0.0 14.7 212.0 180.9 1,146.6 965.7 1,646.0 26.36 .03794 1.3 16.0 216.3 185.3 1,147.9 962.7 1,519.0 24.33 .04110 2.3 17.0 219.4 188.4 1,148.9 960.5 1,434.0 22.98 .04352 3.3 18.0 222.4 191.4 1,149.8 958.3 1,359.0 21.78 .04592 4.3 19.0 225.2 194.3 1,150.6 956.3 1,292.0 20.70 .04831 5.3 20.0 227.9 197.0 1,151.5 954.4 1,231.0 19.72 .05070 10.3 25.0 240.0 209.3 1,155.1 945.8 998.4 15.99 .06253 15.3 30.0 250.2 219.7 ,158.3 938.9 841.3 13.48 .07420 20.3 35.0 259.2 228.8 ,161.0 932.2 727.9 11.66 .08576 25.3 40.0 267.1 236.9 ,163.4 926.5 642.0 10.28 .09721 30.3 45.0 274.3 244.3 ,165.6 921.3 574.7 9.21 .1086 40.3 55.0 286.9 257.2 ,169.4 912.3 475.9 7.63 .1311 50.3 65.0 297.8 268.3 1,172-. 8 904.5 406.6 6.53 .1533 60.3 75.0 307.4 278.2 1,175.7 897.5 355.5 5.71 .1753 70.3 85.0 316.0 287.0 1,178.3 891.3 315.9 5.07 .1971 80.3 95.0 323.9 295.1 1,180.7 885.6 284.5 4.57 .2188 90.3 105.0 331.1 302.6 1,182.9 880.3 258.9 4.16 .2403 100.3 115.0 337.8 309.5 1,185.0 875.5 237.6 3.82 .2617 125.3 140.0 352.8 325.0 1,189.5 864.6 197.3. 3.18 .3147 150.3 165.0 365.7 338.4 1,193.5 855.1 169.0 2.72 .3671 200.3 215.0 387.7 361.3 1,200.2 838.9 131.5 2.12 .4707 360 PRACTICAL HEATING AND VENTILATION TABLE XXXIX MATERIALS FOR BRICKWORK OF TUBULAR BOILERS Boilers. Common Brick. Fire Brick. Sand, Bushels. Cement, Barrels. Fire Clay, Pounds. Lime, Barrels. Single Setting 30in.x 8ft. 5,200 320 42 5 192 2 30 in. x 10 ft. 5,800 320 46 5 1 A 192 2M 36in.x 8ft. 6,200 480 50 6 288 2U 36in.x Oft. 6,600 480 53 y> 288 2% 36 in. x 10 ft. 7,000 480 56 7 288 3 36 in. x 12 ft. 7,800 480 62 8 288 3M 42 in. x 10 ft. 10,000 720 80 10 432 4 42 in. x 12 ft. 10,800 720 86 11 432 tu 42 in. x 14 ft. 11,600 720 92 ii-M 432 4H 42 in. x 16 ft. 12,400 720 99 12H 432 5 48 in. x 10 ft. 12,500 980 100 1% 590 514 48 in. x 12 ft. 13,200 980 108 W/2 590 5y 48 in. x 14 ft. 14,200 980 116 14^ 590 5 : ^ 48 in. x 16 ft. 15,200 980 124 15^ 590 6 54 in. x 12 ft. 13,800 1,150 108 13M 690 &A 54 in. x 14 ft. 14,900 1,150 117 15 690 6 54 in. x 16 ft. 16,000 1,150 126 16 690 6U 60 in. x 10 ft. 13,500 1,280 108 13^ 768 5 1 A 60 in. x 12 ft. 14,800 1,280 118 14?4 768 6 60 in. x 14 ft. 16,^00 1,280 128 16 768 &A 60 in. x 16 ft. 17,400 1,280 140 11M 768 7 60 in. x 18 ft. 18,^00 ,280 148 18*1 768 iy> 66 in. x 16 ft. 19,700 ,400 157 IW 840 8 66 in. x 18 ft. 21,000 ,400 168 21 840 8H 72 in. x 16 ft. 20,800 ,550 166 20^ 930 &A 72 in. x 18 ft. 22,000 ,550 175 22 930 9 Two Boilers in a Battery 30in.x 8ft. 8,900 640 70 9 384 3^ 30 in. x 10 ft. 9,600 640 76 WA 384 4 36 in. x 8ft. 10,500 960 84 wy 2 576 4M 36 in. x 9 ft. 11,100 9CO 88 11 576 4H 36 in. x 10 ft. 11,800 960 95 12 576 4^ 36 in. x 12 ft. 13,000 960 104 13 576 5M 42 in. x 10 ft. 17,500 1,440 140 17M 864 7 42 in. x 12 ft. 18,600 1,440 148 isy 2 864 VA 42 in. x 14 ft. 19,900 1,440 159 20 864 8 42 in. x 16 ft. 21,200 1,440 168 21 864 8^ 48 in. x 10 ft. 21,400 1,960 170 1H ,180 8M 48 in. x 12 ft. 22,300 1,960 178 22# ,180 9 48 in. x 14 ft. 23,900 1,960 190 24 ,180 &A 48 in. x 16 ft. 25,100 1,960 200 25 ,180 10 54 in. x 12 ft. 23,300 2,300 186 23^ ,380 9% 54 in. x 14 ft. 24,800 2,300 198 25 ,380 10 54 in. x 16 ft. 26,300 2,300 210 26^ ,380 10^ 60 in. x 10 ft. 22,600 2,560 180 22H ,536 9 60 in. x 12 ft. 24,800 2,560 198 25 ,536 10 60 in. x 14 ft. 26,800 2,560 214 27 ,536 10^ 60 in. x 16 ft. 28,900 2,560 230 29 ,536 11^ 60 in. x 18 ft. 31,000 2,560 248 31 ,536 12H 66 in. x 16 ft. 33,100 2,800 264 33 ,680 ISM 66 in. x 18 ft. 36,500 2,800 276 35 ,680 14 72 in. x 16 ft. 34,000 3,100 272 34 ,860 ISM 72 in. x 18 ft. 38,000 3,100 282 36 ,860 15 RULES, TABLES, AND OTHER INFORMATION 361 TABLE XL STANDAKD PIPE Extra Strong Actual Nominal Nominal Size, Price Outside Inside Thickness, Weight, Inches. per Foot. Diameter, Diameter, Inches. per Foot, Inches. Inches. Pounds. X .11 .405 .205 .100 .29 .11 .540 .294 .123 .54 % ' .11 .675 .421 .127 .74 ^2 .12 .840 .542 .149 1.09 M .15 1.05 .736 .157 1.39 i .22 1.315 .951 .182 2.17 1% .30 1.66 1.272 .194 3.00 .36 1.900 1.494 .203 3.63 2 2 .50 2.375 1.933 .221 5.02 2^ .81 2.875 2.315 .280 7.67 3 1.05 3.500 2.892 .304 10.25 3V4 1.33 4.000 3.358 .321 12.47 4 " 1.50 4.500 3.818 .341 14.97 4/^ 1.95 5.000 4.280 .360 18.22 5 2.16 5.563 4.813 .375 20.54 6 2.90 6.625 5.750 .437 28.58 7 3.80 7.625 6.625 .500 37.67 8 4.30 S.625 7.625 .500 43.00 Double Extra Strong Actual Nominal Nominal Size, Inches. Price per Foot. Outside Diameter, Inside Diameter, Thickness, Inches. Weight per Foot, Inches. Inches. Pounds. 1A .25 .84 .244 .298 1.70 % .30 1.05 .422 .314 2.44 1 .37 1.315 .587 .364 3.65 1M .52 1.66 .885 .388 5.20 \}/> .65 1.90 1.088 .406 6.40 2 " .95 2.375 1.491 .442 9.02 23/2 1.37 2.875 1.755 .560 13.68 3 1.92 3.50 2.284 .608 18.56 33/o 2.45 4.00 2.716 .642 22.75 4 " 2.85 4.50 3.136 .682 27.48 4;Hj 3.30 5.00 3.564 .718 32.53 5 3.80 5.563 4.063 .750 38.12 6 5.30 6.625 4.875 .875 53.11 7 6.25 7.625 5.875 .875' 62.38 8 7.20 8.625 6.875 .875 71.62 00 O Q$ O 00 O r-T t-T of CO S 5 8 8 8 8 8 8 8 8 8 I* a s 2 r-T f of co" co" *oooooooooooo J>OG" ^ G$ O 00 GO O i> ^* f"H J>* CO^OGO^r-^^O^ r-T i-T i-T of of of liliil 0000OO'-HOl>l>Or^ ^T-iOT-HCOt-O?O5O5O5 *-^ O^ Oi CO O$ CO Oi CO CO GO O5 : : : : _r _r ,_r _r ,-r r ? f ! I i-4 I-H" r-T r-T r-T of f - ^^ O5 ^H *^ O^ CO 00 CO 00 ^ GO CO O O5 i"^ w :::::: ^ -r r^ ^ _r _r r-r PL! -0000000000) iooo**3CO GO<3< J>^ so 5Q '^ en & *OV5 CO GO Ci CO O i iO5-^rHW5 GO I~H T-H GO t* CO O CO O OS COO>'CO i i i i I-H O O Ci C5 *O t** GO CO O5 *-O CO CO CO Oi O^O^^O^CiCOG^ >O^CO GO GO GO rH O 05 10 10 ^ O5i IO5COO5>OCOCO '!P*OO5'* l COGOCOl> 10 UO 1C 10 LO 10 LO 10 UO lis- s g ^ l I - 3 ill '> -S S g J2 ^j MH 03 a ^ s 1 3 -2 31 I ' ' a *S 1 1 1 ! si 0; T3 W i SI III o =3 $ M ^H 1 1 RULES, TABLES, AND OTHER INFORMATION 381 TABLE LVII OF THE NUMBER OF THERMAL UNITS CONTAINED IN ONE POUND OF WATER Temper- ature. Number of Thermal Units. In- crease. Temper- ature. Number of Thermal Units. In- crease. Temper- ature. Number of Thermal Units. In- crease. 35 35.000 155 155.339 5.034 275 276 . 985 5.107 40 40.001 5.001 160 160.374 5.035 280 282.095 5.110 45 45.002 5.001 165 165.413 5.039 285 287.210 5.115 50 50.003 5.001 170 170.453 5.040 290 292.329 5.119 55 55.006 5.003 175 175.497 5.044 295 297.452 5.123 60 60.009 5.003 180 180.542 5.045 300 302.580 5 . 128 65 65.014 5.005 185 185.591 5.049 305 307.712 5.132 70 70.020 5.006 190 190.643 5.052 310 312.848 5.136 75 75.027 5.007 195 195.697 5.054 315 317.988 5.140 80 80.036 5.009 200 200.753 5.056 320 323.134 5.146 85 85.045 5.009 205 205.813 5.060 325 328.284 5.150 90 90.055 5.010 210 210.874 5.061 330 333.438 5.154 95 95.067 5.012 215 215.939 5.065 335 338.596 5.158 100 100.080 5.013 220 221.007 5.068 340 343.759 5.163 105 105.095 5.015 225 226.078 5.071 345 348.927 5.168 110 110.110 5.015 230 231.153 5.075 350 354 . 101 5.174 115 115.129 5.019 235 236.232 5.079 355 359.280 5.179 120 120.149 5.020 240 241.313 5.081 360 364.464 5.184 125 125.169 5.020 245 246.398 5.085 365 369.653 5.189 130 130.192 5.023 250 251.487 5.089 370 374.846 5.193 135 135.217 5.025 255 256.579 5.092 375 380.044 5.198 140 140.245 5.028 260 261.674 5.095 380 385.247 5.203 145 145.175 5.030 265 266.774 5.100 385 390.456 5.209 150 150.305 5.030 270 271.878 5.104 390 395.672 5.216 PRACTICAL HEATING AND VENTILATION TABLE LVIII VOLUME AND DENSITY OF AIR AT VARIOUS TEMPERATURES Temperature. Degrees. Volume of 1 Ib. of Air at Atmospheric Presssure of 14.7 Ibs. Cubic Feet. Density or Weight of 1 Cubic foot of Air at 14.7 Ibs. Lbs. 11.583 .086331 32 12.387 .080728 40 12.586 .079439 50 12.84 .077884 62 13.141 .076097 70 13.342 .07495 80 13.593 .073565 90 13.845 .07223 100 14.096 .070942 120 14.592 .0685 140 15.1 .066221 160 15.603 .064088 180 16 . 106 .06209 200 16.606 .06021 210 16.86 .059313 212 16.91 .059135 220 17.111 .058442 240 17.612 .056774 260 18.116 .0552 280 18.621 .05371 300 19.121 .052297 320 19.624 .050959 340 20 . 126 .049686 360 20.63 .048476 380 21.131 .047323 400 21.634 .046223 425 22.262 .04492 450 22.89 .043686 475 23.518 .04252 500 24.146 .041414 525 24.775 .040364 550 25.403 .039365 575 26.031 .038415 600 26.659 .03751 650 27.915 .035822 700 29.171 .03428 750 30.428 .032865 800 31.684 .031561 850 32.941 .030358 900 34.197 .029242 950 35.454 .028206 1,000 36.811 .027241 1,500 49.375 .020295 2,000 61.94 .016172 2,500 74.565 .013441 3,000 87.13 .011499 RULES, TABLES, AND OTHER INFORMATION 383 TABLE LIX INFLUENCE OF THE TEMPERATURE OF AIR UPON THE CONDITIONS OF ITS MOVEMENT Temper- ature in Degrees, Fahr. Relative Velocity Due to the Same Pressure. Relative Pressure Necessary to Pro- duce the Same Velocity. Relative Weight of Air Moved at the Same Velocity. Relative Velocity Necessary to Move the Same Weight of Air. Relative Pressure Necessary to Produce the Velocity to Move the Same Weight of Air. Relative Power Necessary to Move the Same Volume of Air at the Same Velocity. Relative Power Necessary to Move the Same Weight of Air at the Velocity in Column 5 and the Pressure in Column 6. 1 2 3 4 5 6 7 8 30 0.98 1.04 1.04 0.96 0.96 1.04 0.92 40 0.99 1.02 1.02 0.98 0.98 1.02 0.96 50 .00 1.00 1.00 1 00 1.00 1.00 .00 60 .01 0.98 0.98 1.02 1.02 0.98 .04 70 .02 0.96 0.96 1.04 .04 0.96 .08 80 .03 0.94 0.94 1.06 .06 0.94 .12 90 .04 0.93 0.93 1.08 .08 0.93 .17 100 .05 0.91 0.91 1.10 .10 0.91 .21 125 .07 0.87 0.87 1.15 .15 0.87 1.32 150 .09 0.84 0.84 1.20 .20 0.84 1.43 175 1.11 0.81 0.81 1.24 1.24 0.81 1.55 200 1.14 0.78 0.78 1.29 1.29 0.78 1.67 225 1.16 0.75 0.75 1.34 1.34 0.75 1.80 250 1.18 0.72 0.72 1.39 1.39 0.72 1.93 275 1.20 0.69 0.69 .44 1.44 0.69 2.07 300 1.22 0.67 0.67 .49 1.49 0.67 2.22 325 1.24 0.65 0.65 .54 1.54 0.65 2.36 350 1.26 0.63 0.63 .59 1.59 0.63 2.51 375 1.28 0.61 0.61 .63 1.63 0.61 2.66 400 1.30 0.59 0.59 .68 1.68 0.59 2.82 425 1.32 0.58 0.58 .73 1.73 0.58 2.99 450 1.34 0.56 0.56 .78 1.78 0.56 3.17 475 1.35 0.55 0.55 .83 1.83 0.55 3.35 500 1.37 0.53 0.53 .88 1.88 0.53 3.53 525 1.39 0.52 0.52 .93 1.93 0.52 3.72 550 1.41 0.51 0.51 .98 1.98 0.51 3.92 575 1.43 0.49 0.49 2.03 2.03 0.49 4.12 600 1.44 0.48 0.48 2.08 2.08 0.48 4.33 625 1.46 0.47 0.47 2.13 2.13 0.47 4.54 650 1.48 0.46 0.46 2.18 2.18 0.46 4.75 675 1.49 0.45 0.45 2.22 2.22 0.45 4.93 700 1.51 0.44 0.44 2.27 2.27 0.44 5.15 725 1.52 0.43 0.43 2.32 2.32 0.43 5.38 750 1.54 0.42 0.42 2.37 2.37 0.42 5.62 775 1.56 0.41 0.41 2.42 2.42 0.41 5.86 800 1.57 0.40 0.40 2.47 2.47 0.40 6.10 --J 384 PRACTICAL HEATING AND VENTILATION TABLE LX VELOCITY CREATED, VOLUME DISCHARGED AND HORSE POWER REQUIRED WHEN AIR UNDER A GIVEN PRESSURE IN OUNCES PER SQUARE INCH is ALLOWED TO ESCAPE INTO THE ATMOSPHERE In the following table the volume is proportional to the velocity. The power varies as the cube of the velocity. " Blast area " generally means the maximum area over which the velocity of the air will equal the velocity of the pipes at the tips of the floats. If this area is decreased the volume will be decreased, but the pressure will remain constant. If this area is increased the pressure is lowered, but the volume somewhat increased. This table is calculated for 50 F. temperature. Different temperature will effect the result. The movement of air through pipes will also change results. Pressure Ounces per Square Inch. VELOCITY OF AIR ESCAPING INTO ATMOSPHERE. Volume Dis- charged in One Minute Through Effective Area of One Square Inch, in Cubic Feet. Horse Power of Air Blast. In Feet per Second. In Feet per Minute. l /S 30.47 1,828 12.69 0.0004 43.08 2,585 17.95 0.001 % 52.75 3,165 21.98 0.002 H 60.90 3,654 25.37 0.003 % 68.07 4,084 28.36 0.005 % 74.54 4,473 31.06 0.006 % 80.50 4,830 33.54 0.008 1 86.03 5,162 35.85 0.01 1M 96.13 5,768 40.06 0.014 i*2 105.25 6,315 43.86 0.02 iH 113.64 6,818 47.34 0.023 2 121.41 7,284 50.59 0.028 2M 128.70 7,722 53.63 0.033 2^2 135.59 8,136 56.50 0.039 2M 142.14 8,528 59.22 0.044 3 148.38 8,903 61.83 0.05 &/ 2 160.10 9,606 66.71 0.06 4 170.98 10,259 71.24 0.08 4^ 181 . 16 10,870 75.48 0.09 5 190.76 11,446 79.48 0.11 5^ 199.86 11,992 83.24 0.12 6 208.53 12,512 86.89 0.14 7 224.77 13,486 93.66 0.18 8 239.80 14,388 99.92 0.22 9 253.83 15,230 105.76 0.26 10 267.00 16,020 111.25 0.30 11 279.70 16,768 116.45 0.35 18 291.30 17,478 121.38 0.40 13 302 . 59 18,155 126.06 0.45 14 313.38 18,803 130.57 0.50 15 323.73 19,424 134.89 0.55 16 333.68 20,021 139.03 0.61 17 343.26 20,596 143.03 0.66 18 352.52 21,151 146.88 0.72 19 361.46 21,688 150.61 0.78 20 370.13 22,208 154.22 0.84 RULES, TABLES, AND OTHER INFORMATION 385 TABLE LXI MOISTURE ABSORBED BY AIR The Quantity of Water Which Air is Capable of Absorbing to the Point of Maximum Saturation, in Grains per Cubic Foot for Various Temperatures Degrees. Fahrenheit. Grains in a Cubic Foot. Degrees Fahrenheit. Grains in a Cubic Foot. 10 1.1 85 12.43 15 1.31 90 14.38 20 1.56 95 16.60 25 1.85 100 19.12 30 2.19 105 22.0 32 2.35 110 25.5 35 2.59 115 30.0 40 3.06 130 42.5 45 3.61 141 58.0 50 4.24 157 85.0 55 4.97 170 112.5 60 5.82 179 138.0 65 6.81 188 166.0 70 7.94 195 194.0 75 9.24 212 265.0 80 10.73 ... 386 PRACTICAL HEATING AND VENTILATION i i I C^ 2 a j Q< >O O (N 0? 0< s OT O 00 G^ (N G^ O O^ (N C<^ T-l CO X O* *O b- O< GO CO T}< TJ< Tj< 6 *O 2 i : i % 3 % 3 N H Kijj I CO O5 TF GO rH GO GO GO * * O 5 i g rH TH 'o O Q^ b- I-H ^ CO CO * * 5 5 1 O rH S 2 i O CO O *? b-. O5 * * O 5 5 O a O a "* O 5 Wi CO CO 1 "5 00 O5 * GO i i O b* 00 00 00 00 GO cq tO to CO 00 OS O b- 00 CO 00 CO OS O5 rH i SI 3 % % S Temperature of the Air, Degrees Fahrenheit. <5* o* o* o* < a* * CO Th to CO b- 00 OS RULES, TABLES, AND OTHER INFORMATION 387 -^ -^ 1 1 JZ 9 o OR i i i i .r-T ^r o< Oo~ PRACTICAL HEATING AND VENTILATION TABLE LXIV PRESSURE IN INCHES OF WATER AND CORRESPONDING PRESSURE IN OUNCES, WITH VELOCITIES OF AIR DUE TO PRESSURES Pressure per Square Inch in Inches of Water. Corresponding Pressure in Ounces per Square Inch. Velocity Due to the Pres- sure in Feet per Minute. Pressure per Square Inch in Inches of Water. Corresponding Pressure in Ounces per Square Inch. Velocity Due to the Pres- sure in Feet per Minute. y*> .01817 696.78 H .36340 3,118.38 X .03634 987.66 H .43608 3,416.64 y* .07268 1,393.75 y s .50870 3,690.62 %> . 10902 1,707.00 i .58140 3,946.17 y . 14536 1,971.30 iM .7267 4,362.62 %> .18170 2,204.16 IK .8721 4,836.06 y* .21804 2,414.70 IK 1.0174 5,224.98 1 A .29072 2,788.74 2 1 . 1628 5,587.58 TABLE LXV PRESSURE IN OUNCES PER SQUARE INCH WITH VELOCITIES OF AIR DUE TO PRESSURES Pressure in Ounces per Square Inch. Velocity Due to the Pres- sure in Feet per Minute. Pressure in Ounces per Square Inch. Velocity Due to the Pres- sure in Feet per Minute. Pressure in Ounces per Square inch. Velocity Due to the Pres- sure in Feet per Minute. .25 2,582 2.75 8,618 7.50 14,374 .50 3,658 3.00 9,006 8.00 14,861 .75 4,482 3.50 9,739 9.00 15,795 1.00 5,178 4.00 10,421 10.00 16,684 1.25 5,792 4.50 11,065 11.00 17,534 1.50 6,349 5.00 11,676 12.00 18,350 1.75 6,861 5.50 12,259 13.00 19,138 2.00 7,338 6.00 12,817 14.00 19,901 2.25 7,787 6.50 13,354 15.00 20,641 2.50 8,213 7.00 13,873 16.00 21,360 RULES, TABLES, AND OTHER INFORMATION 389 TABLE LXVI WEIGHTS OF GALVANIZED IRON PIPE PER LINEAL FOOT Diameter of Pipe GAUGE OF IRON NUM BERS. in Inches. 18 20 22 24 26 3 4 2% 2% 1% 2% 13^ 1% ft 1 5 6 3% 3% 2% 3 2 2% 1% 2 1% 7 3/^ 2% 2% 2 8 5% 4 3 2% 2% 9 5% 43^ 3% 3 2/^8 10 11 6% 6% 4% 5% 3% 3% 2% 12 7l2 5% 4% 3% 3 13 8 6% 3% 14 83^2 6% 4% 4% 15 9% 7% 5% 4% 3% 16 9% 7% 5 4 17 10% 8 6 2 5% 4% 18 10% 83^ 6% 53^ 4/^ 19 11H 9 6% 5% 4% 20 12 93/2 7 6 5% 21 22 13% 9% 10% 7% 6% 5% 23 14 11 8% 7 6 24 14% 113^ 8% 73^ 63^ 26 15% 123/2 9% 7% 63^ 28 16% 13/^ 9% &A 7 30 18 14 103^ 9 73^ 32 34 19% 20% 15 15% 11% 12 9% 10% 8 36 213^ 16% 123^ 10% 9 2 38 22% 18 133^ 113^ 93^ 40 24 18% 14 12 10 42 25 14% 123/2" 103^ 44 46 26% 27^ 203^ 16 " 13 13% 11 48 28^ 22% 16% 14% 12 2 50 29% 23 15 123^ 52 31% 24% 18% 54 32^ 25 18% , 56 33% 26 19 58 35 26% 20% 60 36% 20% . 63 38% 29 2 21% . 66 40 30% 22% , 69 41% 32% 23% . . 72 43^ 33% 25 The figures in bold-faced type represent weight of round piping ordinarily used in heating work. INDEX Advantages of steam heating, 114. Air, circulation of, by direct radia- tion, 98. Air, circulation of, by indirect radia- tion, 99. Air cleansing, 233, 234. Air compressor, Johnson, 312. Air, conditions of its movement, 383. Air ducts for ventilating, 248, 250. Air ducts, indirect heating, 94. Air, expansion of, 349. Air, humidity of, 259, 260. Air, influence of the temperature, 383. Air, loss of pressure in pipes, 379. Air, method of measuring velocity, 258. Air, moisture absorbed by, 385. Air necessary for ventilation, 213, 218. Air required to burn coal, 349. Air, table of velocities due to pressure, 388. Air valve, 77. Air valve, compression, 77. Air valves, automatic, 78, 79. Air, velocity at furnace register, 349. Air, velocity, volume, and horse power required, 384. Air, volume and density at various pressures, 382. Air, volume necessary to maintain given standard of purity, 387. Air, wire screen for cleansing, 233. Altitude gauge, 146. Anemometer, description of, 258. Angles, measurements for, 209, 210, 349. Angle valve, 74. Apparatus for testing blower systems, 257, 261. Area of circle, 350. Areas of circles, table of, 358. Artificial heating apparatus, evolu- tion of, 22. Artificial heating, methods of, 23. Artificial water line, 205, 206. Asbestos, 295. Aspirating coil, to determine size of, 349. Atmosphere, moisture in the, 386. Attention to boilers, 330, 331. Automatic damper regulator, 50, 53, 300. Automatic water feeders, 287. Back-pressure valves, 282. Belting, horse power of, 368. Belting, rule for finding length, 369. Blow-off cock, 53, 54. Boiler, All Right, 33. Boiler, Bundy, 33. Boiler, common type of upright tubu- lar, 28. Boiler covering, 293. Boilers, cross-connecting, 206, 209. Boiler, Dunning, 29. Boilers, early types of, 26. Boiler explosions, 340, 341. Boilers, feed water required, 364. 391 392 INDEX Boiler, Florida, 32. Boiler, Gold, 30. Boiler, Gorton, 34. Boilers, grate surface of, 41. Boiler, Haxtun, 29. Boiler, locomotive fire-box, 31. Boiler, manner of bricking locomo- tive fire-box, 43, 44. Boiler, Mills, 30. Boiler, original type of Furman, 32. Boiler, Page Safety Sectional, 32. Boilers, proper attention to, 330, 331. Boilers, removing oil and dirt from, 331, 332. Boiler setting, 42. Boiler, shell of Dunning, 28. Boiler, standard type of horizontal tubular, 27. Boiler surfaces and settings, 40. Boiler, volunteer, 32. Boilers, water surface of, 41. Boiler,. what constitutes a good one, 38. Boiling point of water, 347. Boiling point of water, table, 142. Boiling points of fluids, 353. Box base for direct-indirect radiator, 96. Boxing indirect radiators, 92, 93. Brass, to clean, 351. Branch tees, 69, 71. Bricking tubular boilers, materials required, 360. Brick setting tubular boilers with full fronts, 46. Brick setting tubular boilers with half fronts, 48. British thermal heat unit (B. T. IL), 19. Bronzing, painting, and decoration, 335, 336. Broomell vapor-heating system, 178, 181. Bucket traps, 263, 264. Business methods, 316, 328. Capacities of pumps, 366. Capacity of stacks, 363. Care of heating apparatus, 329, 330. Care of tools, 333, 334. Casing indirect radiators, 92, 93. Cast-iron fittings, 69. Cast iron, to harden, 352. Cast-iron fittings, types of, 70. Cast-iron flanges, 71. Cast-iron flanges, schedule of, 71. Cement for leaky boilers, 350. Cement for steam boilers, 350. Central - station hot -water heating, 291, 292. Check valve, 76. Chimney flue, 56. Chimney flue, capacity of, 59. Chimney flue, elements of, 59. Chimney flue, proper construction of, 56, 58. Chimney flue, table of sizes, 58. Chimneys, tables of heights and area, 61. Circles, table of areas, 358. Circle, to find area of, 350. Circle, to find circumference of, 349. Circle, to find diameter of, 350. Circulation of air by direct radiator, 98. Circulation of air by indirect radiator, 99. Circumference of circle, 349. Coal, air necessary to burn, 349. Coal, heat units in, 348. Coal, weight of anthracite, 348. Coal, weight of bituminous, 348. INDEX 393 Coil stands and hook plates, 90. Coils for tanks, sizes of, 198. Comparison of thermometric scales, 357. Condensing engines, water required, 349. Contracts, special features of, 328. Contracts, specifications of, 319, 328. Cost, manner of estimating, 317, 318. Cost of coal for steam power, 362. Cost of mechanical heating and ven- tilation, 255, 257. Couplings, wrought-iron, malleable, 68. Covering, pipe and boiler, 293, 298. Cross-connecting boilers, 206, 209. Cylindrical tank, to find capacity of, 348, 351. Damper, double, for round flue, 314. Damper, double, for square flue, 314. Damper regulator, automatic, 50, 53, 300. Damper regulator, low-pressure, 51. Damper regulator, manner of con- necting, 52. Decimal equivalents of an inch, table of, 367. Density of air at various tempera- tures, 382. Diameter of circle, 350. Diameter of pipes, table for equal- izing, 378. Diaphragm motor, powers, 304. Diaphragm radiator valve, 303, 313. D. & R. regulator, 307, 308. Direct-indirect radiators, 95, 96. Dirt, removing from boilers, 331, 332. District heating, 288, 292. Domestic water heating, 194, 198. Ducts, sizes of, for indirect heating, 94. Dunham vacuo-vapor system, 183, 187. Early history of heating, 15. Early history of ventilation, 16. Early types of boilers, 26. Eccentric fittings, use of, 114. Efficiency determined by summer tests, 332, 333. Engines for blower systems, types of, 245, 248. Equalizing diameter of pipes, 378. Estimate, form of, 317, 318. Estimating, 316, 319. Estimating radiation, 97, 102. Estimating radiation for greenhouses. 157, 158. Estimating radiation, rules for, 100. 102. Evolution of artificial heating ap- paratus, 22. Exhaust steam, heating capacity of r 118. Exhaust-steam heating, 115, 119. Exhaust-steam heating, necessary fixtures, 116. Exhaust-steam heating, plan of, 117 Exhaust-vacuum systems, 165, 173. Expansion of air, 349. Expansion of pipe, to find, 351. Expansion of water, 347. Expansion tank, 125, 127. Expansion tank, automatic, 127. Expansion-tank connections, 126, 127, 134, 135, 142, 143. Expansion tank, table of sizes, 128. Expansion tank, to determine size, 349. Expansion traps, 263. 394 INDEX Explosion of boilers, 340, 341. Explosions, prevention of, 341, 342. Factory heating and ventilating, 253, 255. Fan engines for blower systems, 245, 248. Fans for blowing and exhausting, 238, 240. Features of contracts, 328. Feed-water heaters, 275, 276. Feed-water required by boilers, 364. Firing tools and brushes, 54. Fittings, cast-iron, 69. Fittings, eccentric, 114. Flanges, cast-iron, 70, 71. Float traps, 264, 265. Floor and ceiling plates, 149. Flues, area required for ventilation, 373, 376. Fluids, boiling points of, 353. Forms of radiating surfaces, 81. Fuel, consumption of, 348. Fusible plug, 54. Future of vacuum heating, 187, 188. Galvanized iron pipe, weight of, 377, 389. Gate valve, 74, 75, 76. Gauge, altitude, 146. Gauge glass and water column, 53, 54. Gauges and their fractional equiva- lents, 351. Globe valve, 74, 75, 76. Gorton system vacuum heating, 181, 183. Governor for pump, 280, 281. Grate surface in boilers, 41. Greenhouse heating, 155, 162. Greenhouse piping, methods of, 159, 162. Guaranty, bad features of, 337, 340. Guaranty, forms of, 337, 340. Healthfulness of furnace heating vs. steam or hot water, 25. Heart of the heating system, 26. Heat absorbed by bodies, 21. Heat, how measured, 19. Heat, how transferred, 18, 20. Heat, nature of, 18. Heat unit, British thermal unit, 19. Heat units in anthracite coal, 348. Heat, utilizing waste, 342, 346. Heaters, feed-water, 275, 276. Heaters for blower systems, types of, 239, 245. Heating apparatus, average life and cost, 24. Heating apparatus, care of, 329, 330. Heating, artificial methods of, 23. Heating by exhaust steam, 115, 119. Heating by hot water, 120, 141. Heating by steam, 103, 114. Heating capacity of exhaust steam, 118. Heating capacity of tubular boilers, 349. Heating, district method, 288, 292. Heating, early history of, 15. Heating greenhouses, 155, 162. Heating, miscellaneous, 189, 198. Heating of swimming pools, 189, 194. Heating system, Broomell vapor, 178, 181. Heating system, Dunham, 183, 187. Heating system, Gorton, 181, 183. Heating system, K-M-C (Morgan), 174, 175. Heating system, Paul, 168, 173. Heating system, Ryan, 178, 179. INDEX 395 Heating system, Trane mercury seal, 175, 178. Heating systems, vacuum-exhaust, 165^ 173. Heating system, vacuum- vapor, 183. Heating system, Vacuum Vapor Com- pany, 181. Heating system, Van Auken, 173. Heating system, vapor, 178, 180. Heating system, Webster, 165, 168. Heating, vacuum systems, 163, 188. Heating and ventilating factories, 253, 255. Heating and ventilating, relative cost, 255, 257. Heating water for domestic purposes, 194, 198. High temperature thermometer, 258. Honeywell heat generator, 150, 152. Hook plates and coil stands, 90. Horse power, definition of, 19. Horse power of belting, 368. Hot-blast heating and ventilation, 224, 261. Hot-blast heating, growth and im- provement, 224, 225. Hot- water heaters, 35. Hot-water heater, Carton, 37. Hot-water heater, early type of Gur- ney, 35. Hot-water heater, Hitchings, 36. Hot-water heater, improved Gurney, 36. Hot-water heater, perfect, 36. Hot-water heater, Spence, 35. Hot-water heater, thermo, 38. Hot-water heating, 120, 140. Hot-water heating appliances, 146, 154. Hot-water heating, central - station method, 291, 292. Hot-water heating, methods, 121. Hot- water heating, modified over-, head system, 135. Hot-water heating, pipe connections, 132. Hot-water heating, pressure systems, 141, 145. Hot-water heating, size of main for one pipe, 139. Hot-water heating, sizes of mains two-pipe system, 124. Hot-water heating, special fittings, 138. Hot-water heating, specifications and bid, 324, 328. Hot- water heating, the circuit sys- tem, 136, 139. Hot-water heating, the overhead sys- tem, 128, 136. Hot- water heating, the two-pipe sys- tem, 121, 128. Hot-water heating, why water circu- lates, 139, 140. Hot- water radiator connections, 201, 203. Hot-water thermometer, 147, 148. Hot- water thermometer, method of attaching, 148. Howard regulator, 308, 309. Hygrometer, wet and dry bulb, 259, 261. Importance of ventilation, 211, 213. Improper use of tees, 203. Indirect heating, location of regis- ters, 91, 93. Indirect heating, sizes of air ducts and registers, 94. Indirect heating, surface required, 100, 102. Indirect radiators, 84, 92, 93. 396 INDEX Indirect radiators, casing of, 92, 93. Indirect radiators, method of sup- porting, 95. Injectors, 283, 285. Inlets, location of those for fresh air, 221. Inspirators, 285, 286. Johnson air compressor, 312. Johnson regulator, 312, 313. Johnson system of temperature reg- ulation, 311, 315. K-M-C (Morgan) system, vacuum heating, 174, 175. Labor-saving suggestions, 334, 335. Latent heat of steam at various pressures, 359. Lawler regulator, 311. Leaky boilers, cement for, 350. Length of belts, rule for determining, 369. Location of fresh-air inlets, 221. Location of registers, indirect heat- ing, 91, 93. Locating radiating surfaces, 91. Loss of pressure of air delivery through pipes, 379. Machinery, to prevent rusting, 352. Marble, to remove stains from, 352. Measurement of offsets, 349. Measurements for 45 and other an- gles, 209, 210. Measurements for setting tubular boilers with full fronts, 45. Measurements for setting tubular boilers with half fronts, 47. Measuring pipe and fittings, 72. Mechanical heating and ventilation, an ideal system, 229, 238. Mechanical heating and ventilation, capacity required, 227, 228. Mechanical heating and ventilation, methods employed, 225, 227. Mechanical ventilating apparatus, details of, 248, 252. Mechanical ventilation, American Blower Co.'s method, 234. Mechanical ventilation and hot blast heating, 224, 261. Mechanical ventilation, Buffalo Forge Co.'s method, 230, 233. Mechanical ventilation, growth and improvement, 224, 225. Mechanical ventilation, New York Blower Co.'s method, 235. Mechanical ventilation, quality of air supplied, 228, 229. Mechanical ventilation, Sturtevant method, 236. Mechanical ventilation, typical meth- od for schools, 238. Melting points of metals, 353. Metals, melting points of, 353. Metal, to inscribe, 352. Methods of artificial heating, 23. Methods of greenhouse piping, 159, 162. Methods of heating business, 316, 328. Methods of pipe construction, 203, 205. Methods of ventilation, 218, 223. Metric system, table of, 355. Minneapolis regulator, 310. Miscellaneous, 329, 346. Miscellaneous heating, 189, 198. Mitre pipe coil, 86. Mixing dampers, 250, 252. Moisture absorbed by air, 385. Moisture in the atmosphere, 386. INDEX 397 National regulator, 306, 307. Nature of heat, 18. Nipples, table of sizes, 68. Nipples, wrought-iron, 67. Offset, measurement of, 349. Oil, removing from boilers, 331, 332. Oil separators, 273, 275. One-pipe system, hot-water, 137, 139. One-pipe system, steam, 103, 111. O. S. hot- water fitting, 131. Oxygen, necessity and importance of, 211, 212. Painting, bronzing, and decoration, 335, 336. Paul system, exhaust-steam heating, 168, 173. Phelps heat retainer, 153, 154. Pipe, 63. Pipe and fittings, method of measur- ing, 72. Pipe and radiator connections, 199, 210. Pipe, bending, 64. Pipe coils, 86, 88. Pipe coils, method of building, 89. Pipe construction, methods of, 203, 205. Pipe covering, 293, 298. Pipe covering, tests, 294. Pipe, expansion of, 64, 65, 351. Pipe hangers, 65. Pipe, table of extra strong, 361. Pipe, table of double extra strong, 361. Pipe, table of standard wrought-iron, 63. Pipe, threading, 64. Pipe, to ascertain whether wrought- iron or steel, 66. Pipe, wrought-iron or steel, 66. Plates, floor and ceiling, 149. Powers system heat regulation, 303, 305. Pressure appliances, 150, 154. Pressure of water, 348. Prevention of explosions, 341, 342. Properties of saturated steam, 359. Proposal and bid, 319, 328. Pulleys, size and speed of, 350. Pump, diameters and capacities, 366. Pump governors and regulators, 280, 281. Pumps, steam, 276, 279. Pumps, vacuum, 279, 280. Radiating power of bodies, 20. Radiating surfaces, forms of, 81. Radiating surfaces, pipe coils, 86, 88. Radiating surfaces, proper location, 91. Radiation for greenhouses, 157, 158. Radiation, rules for estimating, 100, 102. Radiator and pipe connections, 199, 210. Radiator connections, hot- water, 201, 203. Radiator connections, steam, 199, 201. Radiators, decoration of, 335, 336. Radiators, direct-indirect, 95, 96. Radiators, indirect, 84, 92, 93. Radiators, types of, 81, 85. Radiator valves, 74. Radiators, wall, 85. Radiators, window, 85. Reducing pressure valves, 283. Registers for indirect heating, sizes of, 94. Regulator, D. & R., 307, 308. 398 INDEX Regulator, Howard, 308, 309. Regulator, Imperial Climax, 300. Regulator, Johnson, 312, 313. Regulator, Lawler, 311. Regulator, Minneapolis, 310. Regulator, National, 306, 307. Regulator, Powers, 301, 302. Regulators, pump, 280, 281. Relation between temperature of feed water and evaporative capac- ity of boiler, 364. Relative pressure, velocity and weight of air, 383. Removing grease stains from mar- ble, 352. Removing oil and dirt from boilers, 331, 332. Removing rust from steel, 352. Required flue area for given velocity and air change, 373. Required flue area for passage of air, 374, 375, 376. Required quantity of feed water to supply boiler, 364. Return bend pipe coil, 87. Return branch tee coil, 87. Revolutions of pulleys, to find, 350. Round galvanized iron pipe and el- bows, weight of, 377. Rule for calculating size and speed of pulleys, 350. Rules for estimating radiation for greenhouses, 157, 158. Rules, tables, and other information, 347, 389. Ryan system, vacuum heating, 178, 179. Safety valves, 49. Safety valves on expansion tanks, 143, 144. Saturated steam, properties of, 359. Schoolhouse heating and ventilating, typical methods, 230, 238. Schoolhouse ventilation, cost of, 256, 257. Schoolhouse ventilation, Massachu- setts laws for, 215. Separators, steam and oil, 273, 275. Setting direct-indirect radiators, 95. Setting tubular boilers, 45, 48. Shell of Dunning boiler, 28. Sizes of steam mains, 114. Special features of contracts, 328. Specific gravity of steam, 349. Specifications for hot-water heating, 324, 328. Specifications for steam heating, 319, 323. Stacks, capacity of, 363. Standard flanges, schedule of, 71. Standard type of tubular boilers, 27. Standard pipe, table of, 63, 361. Steam appliances, 262, 287. Steam for cooking and manufactur- ing, 198. Steam gauge, 50. Steam gauge, low-pressure, 51. Steam heating, advantages of, 114. Steam-heating apparatus, 103, 114. Steam heating, exhaust, 115, 119. Steam heating, methods of, 103, 104. Steam heating, specifications and bid, 319, 323. Steam heating, the circuit system, 104. Steam heating, the divided circuit system, 107, 109. Steam heating, the one-pipe system with dry returns, 108, 110. Steam heating, the overhead system, 108, 111. INDEX 399 Steam heating, the two-pipe system, 112, 113. Steam mains, sizes of, 114. Steam power, cost of coal, 362. Steam pumps, 276, 279. Steam-radiator connections, 199, 201. Steam regulator, Imperial Climax, 300. Steam separators, 273, 275. Steam, specific gravity of, 349. Steam, table of temperatures, 359. Steam traps, 262, 266. Steam, value of exhaust, 115. Steel, to remove rust from, 352. Suggestions for saving labor, 334, 335. Summer care of heating apparatus, 329, 330. Summer tests to determine efficiency, 332, 333. Supporting indirect radiators, 95. Swimming pools, heating of, 189, 194. Table I. Radiating power of bodies, 20. Table II. Measurements for setting tubular boilers with full fronts, 45. Table III. Measurements for setting tubular boilers with half fronts, 47. Table IV. Sizes of chimneys, 58. Table V. Heights of chimneys, 61. Table VI. Measurements of stand- ard and wrought-iron pipe, 63. Table VII. Expansion of wrought- iron pipe, 65. Table VIII. Length and size of wrought-iron nipples, 69. Table IX. Schedule of standard flanges, 71. Table X. Indirect work: sizes cold and hot air ducts, 94. Table XI. Sizes of steam mains, 114. Table XII. Sizes of mains two- pipe hot- water system, 124. Table XIII. Expansion tank sizes, 128. Table XIV. Sizes of mains for one- pipe hot water, 139. Table XV. Boiling temperatures of water at various pressures, 142. Table XVI. Temperatures green- house heating, 158. Table XVII. Schedule of water temperatures greenhouse heating, 158. Table XVIII. Capacities of hot- water heaters for swimming pools, 192. Table XIX. Sizes of tanks and heaters domestic hot-water sup- ply, 197. Table XX. Sizes of steam coils for storage tanks, 198. Table XXI. Measuring 45 and other angles, 210. Table XXII. Consumption of air by various modes of artificial light- ing, 213. Table XXIII. Air supply necessary for various buildings, 214. Table XXIV. Cubic feet of air con- taining four parts of carbonic acid in ten thousand supplied per per- son, 218. Table XXV. Temperature, weight, and humidity of air, 229. Table XXVI. Temperature table, Schott's balanced column system, 291. Table XXVII. Tests of pipe cover- ing, 294. Table XXVIII. Tests to determine efficiency, 333. 400 INDEX Table XXIX. Gauges and their equivalents, 351. Table XXX. Melting points of met- als, 353. Table XXXI. Boiling points of fluids, 353. Table XXXII. Weights and meas- ures, 354. Table XXXIII. Metric system of weights and measures, 355. Table XXXIV. Minimum and mean temperatures of various cities, 356. Table XXXV. Comparison of ther- mometric scales, 357. Table XXXVI. Area of circles and sides of squares, 358. Table XXXVII. Temperature of steam at various pressures, 359. Table XXXVIII. Properties of sat- urated steam, 359. Table XXXIX. Materials for brick- work of tubular boilers, 360. Table XL. Standard pipe, 361. Table XLL Cost of coal for steam power, 362. Table XLII. Capacities of stacks, 363. Table XLIIL Relation between temperature of feed water and evaporative capacity of boiler, 364. Table XLIV. - Feed water required by boiler, 364. Table XLV. Vacuum, pressure and temperature, etc., 365. Table XLVI. Pump diameters and capacities in gallons, 366. Table XL VII. Decimal equivalents of an inch, 367. Table XLVIIL Horse power of a leather belt one inch wide, 368. Table XLIX. Number of square inches of flue area required per 1,000 cubic feet of contents for given velocity and air change, 373. Table L. Flue area required for the passage of a given volume of air at a given velocity, 374. Table LI. Flue area required for the passage of a given volume of air at a given velocity (continued), 375. Table LII. Flue area required for the passage of a given volume of air at a given velocity (continued), 376. Table LIIL Weight of round gal- vanized iron pipe and elbows, of the proper gauges for heating and ventilating systems, 377. Table LIV. Equalizing the diam- eters of pipes, 378. Table LV. Air: Loss of pressure in ounces per square inch for varying velocities and varying diameters of pipes, 379. Table LVL Number of cubic feet of dry air that may be heated through 1 (F.) by the condensation of ope pound of steam, 380. Table LVIL Number of thermal units contained in one pound of water, 381. Table LVIII. Volume and density of air at various temperatures, 382. Table LIX. Influence of the tem- perature of air upon the conditions of its movement, 383. Table LX. Velocity created, volume discharged and horse power rer quired when air under a given pressure in ounces per square inch INDEX 401 is allowed to escape in the atmos- phere, 384. Table LXL Moisture absorbed by air, 385. Table LXIL Moisture in the atmos- phere, 386. Table LXIII. Volume of air neces- sary to maintain a standard of pur- ity, 387. Table LXIV. Pressure in inches of water and corresponding pressure in ounces, with velocities of air due to pressures, 388. Table LXV. Pressure in ounces per square inch with velocities of air due to pressures, 388. Table LX VI .Weights of galvan- ized iron pipe per lineal foot, 389. Table of weights and measures, 354. Tables, rules and other information, 347, 389. Tank capacities, domestic water heat- ing, 197. Tees, improper use of, 203. Temperature of steam, table of, 359. Temperature regulation and heat control, 299, 315. Temperatures of various cities in the United States, 356. Thermal units in one pound of water, 381. Thermometer, high temperature, 258. Thermometer, hot-water, 147, 148. Thermometric scales, comparison of, 357. Thermostat, Howard, 308. Thermostat, Johnson, 312. Thermostat, Lawler, 311. Thermostat, Minneapolis, 310. Thermostat, National, 306. Thermostat, Powers, 301, To clean brass, 351. To harden cast iron, 352. To prevent machinery from rusting, 352. To remove rust from steel, 352. To remove stains from marble, 352. Tools, care of, 333, 334. Trane mercury seal system, vacuum heating, 175, 178. Traps, bucket, 263, 264. Traps, expansion, 263. Traps, float, 264, 265. Traps, return, 266, 273. Tubular boilers, heating capacity of, 349. Tubular boilers, materials for brick- ing, 360. Tubular boilers, measurements for setting, 45, 47. Tubular boilers, plan of brick setting, 46, 48. Underground pipe, covering for, 296, 297. Useful information, 347, 389. Utilizing waste heat, 342, 346. Vacuum exhaust systems, 165, 173. Vacuum heating, future of, 187, 188. Vacuum heating systems, 163, 188. Vacuum, pressure and temperature, table of, 365. Vacuum pumps, 279, 280. Vacuum, relief on expansion tank. 143, 144. Vacuum Vapor Company's system, 181. Vacuum-vapor heating system, 183. Valves, 73. Valves, angle, 74. Valves, back-pressure, 282. 402 INDEX Valve, check, 76. Valve, diaphragm radiator, 303, 313. Valves, gate, 74, 75, 76. Valves, radiator, 74. Valves, reducing pressure, 283. Valves, safety, 49. Valve, straightway hot-water, 131. Value of exhaust steam, 115. Van Auken system, vacuum heating, 173. Vapor heating system, 178, 180. Velocity of air due to pressures, 388. Ventilation, 211, 223. Ventilation, air necessary for, 213, 218. Ventilation, early history of, 16. Ventilation, importance of, 211, 213. Ventilation, mechanical, 224, 261. Ventilation, methods of, 218, 223. Ventilation, required area of flues, 373, 376. Volume of air at various tempera- tures, 382. Wall boxes for direct-indirect radia- tors, 95. Waste-heat utilizing, 342, 346. Water, boiling point of, 142, 347. Water column and gauge glass, 53, 54. Water, expansion of, 347. W'ater feeders, automatic, 287. Water, gallons in cylindrical tank, 348, 351. W'ater-line, artificial, 205, 206. Water, pressure of, 348. Water, pressure in inches, 388. Water, pressure in ounces, 388. Water required by condensing en- gines, 349. Water required by tubular boilers, 348. Water surface in boilers, 41. Water, thermal units in one pound, 381. Water, weight of, 347. Weight of anthracite coal, 348. Weight of bituminous coal, 348. Weight of galvanized iron pipe, 377, 389. Weight of water, 347. Weights and measures, table of, 354. Weights and measures, the metric system, 355. Webster system, exhaust-steam heat- ing, 165, 168. Why hot water circulates, 139, 140. PRACTICAL SCIENTIFIC TECHNICAL EACH BOOK IN THIS CATALOGUE IS WRITTEN BY AN EXPERT AND IS WRITTEN SO YOU CAN UNDERSTAND IT THE mm i mm PUBLISHING COMPANY Publishers of Scientific and Practical Books 132 Nassau Street New York, U. S. A. Any book in this Catalogue sent prepaid on receipt of price. SUBJECT INDEX PAGE Accidents 18 Air Brakes 17, 19 Arithmetics 20 Automobiles 3 Balloons 3 Bevel Gears 14 Boilers 22 Brazing 3 Cams 15 Car Charts 4 Change Gear 14 Charts 3, 4, 22 Chemistry 23 Coal Mining 23 Coke 4 Compressed Air 5 Concrete 5 Cyclopedia 4, 20 Dictionaries 7 Dies 7 Drawing 8, 24 Drop Forging 7 Dynamo 9, 10, 11 Electricity 9, 10. 11, 12 Engines and Boilers 22 Factory Management 12 Flying Machines 3 Fuel 13 Gas Manufacturing 14 Gas Engines 13, 14 Gears 14 Heating, Electric 9 Hot Water Heating 27 Horse-Power Chart 4 Hydraulics 15 Ice Making 15 India Rubber 25 Interchangeable Manufacturing 20 Inventions 15 Knots 15 Lathe Work 16 Lighting (Electric) 9 Link Motion 17 Liquid Air 16 Locomotive Boilers 18 Locomotive Engineering 17, 18, 19 Machinist's Books. . . . 20, 21, 22 PAGE Manual Training 22 Marine Engines 22 Marine Steam Turbines 29 Mechanical Movements 20, 21 Metal Turning 16 Milling Machines 21 Mining 22, 23 Oil Engines 13 Patents 15 Pattern Making 23 Perfumery 23 Pipes 28 Plumbing . 24 Producer Gas 13 Punches 7 Railroad Accidents 18 Receipt Book 23, 25 Refrigeration 15 Rope Work 15 Rubber Stamps 25 Saws 26 Sheet Metal Working 7 Shop Tools 21 Shop Construction 20 Shop Management 20 Sketching Paper 8 Smoke Prevention 13 Soldering 3 Splices 15 Steam Engineering 26, 27 Steam Heating 27 Steam Pipes 28 Steel 28 Superheated Steam 17 Switchboards 9, 11 Tapers 16 Telephone 12 Threads 22 Tools 20, 22 Turbines 29 Ventilation 27 Valve Gear 19 Valve Setting 17 Walschaert Valve Gear 19 Watchmaking 29 Wiring 9, 11, 12 Wireless Telephones and Telegraphy. ... 12 ANY OF THESE BOOKS PROMPTLY SENT PREPAID TO ANY ADDRESS IN THE WORLD ON RECEIPT OF PRICE. to Remit. Ey Postal Money Order, Express Money Order, Bank Draft or Registered Letter. CATALOGUE OF GOOD, PRACTICAL BOOKS AUTOMOBILE THE MODERN GASOLINE AUTOMOBILE ITS DESIGN, CONSTRUCTION, MAINTENANCE AND REPAIR. By VICTOR W. PAGE, M. E. The latest and most complete treatise on the Gasoline Automobile ever issued. Written in simple language by a recognized authority, familiar with every branch of the automobile industry. Free from technical terms. Everything is explained so simply that anyone of average intelligence may gain a comprehensive knowledge of the gasoline automobile. The information is up-to-date and includes, in addition to an exposition of principles of construction and description of all types of automobiles and their components, valuable money-saving hints on the care and operation of motor cars propelled by internal combus- tion engines. Among some of the subjects treated might be mentioned: Torpedo and other symmetrical body forms designed to reduce air resistance; sleeve valve, rotary valve and other types of silent motors; increasing tendency to favor worm-gear power-transmission; universal application of magneto ignition; development of automobile electric-lighting systems; block motors; underslung chassis; application of practical self-starters; long stroke and offset cylinder motors; latest automatic lubrication systems; silent chains for valve operation and change-speed gearing ; the use of front wheel brakes and many other detail refinements . By a careful study of the pages of this book one can gain practical knowledge of automobile construction that will save time, money and worry. The book tells you just what to do, how and when to do it. Nothing has been omitted, no detail has been slighted. Every part of the automobile, its equipment, accessories, tools, supplies, spare parts necessary, etc., have been discussed comprehensively. If you are or intend to become a motorist, or are in any way interested in the modern Gasoline Automobile, this is a book you cannot afford to be without. Nearly 600 6x9 pages and more than 500 new and specially made detail il- lustrations, as well as many full page and double page plates, showing all parts of the automobile. Including nine large folding plates. Price $2.50 BALLOONS AND FLYING MACHINES MODEL BALLOONS AND FLYING MACHINES. WITH A SHORT ACCOUNT OF THE PROGRESS OF AVIATION. By J. H. ALEXANDER. This book has been written with a view to assist those who desire to construct a model airship or flying machine. It contains five folding plates of working drawings, each sheet containing a different sized machine. Much instruction and amusement can be obtained from the making and flying of these models. A short account of the progress of aviation is included, which will render the book of greater interest. Several illustrations of full sized airship and flying machines of the latest types are scattered throughout the text. This practical work gives data, working drawings, and details which will assist materially those interested in the problems of flight. 127 pages, 45 illustra- tions, 5 folding plates. Price $1.50 BRAZING AND SOLDERING BRAZING AND SOLDERING. By JAMES F. HOBART. The only book that shows you just how to handle any job of brazing or soldering that comes {.long; tells you what mixture to use, how to make a furnace if you need one. Pull of valuable kinks. The fifth edition of this book has just been published, and to it much new matter and a large number of tested formulas for all kinds of solders and fluxes have been added. Illustrated 25 cents CHARTS MODERN SUBMARINE CHART WITH 200 PARTS NUMBERED AND NAMED. A cross-section view, showing clearly and distinctly all the interior of a Submarine of the latest type. You get more information from this chart, about the construction and opera- tion of a Submarine, than in any other way. No details omitted everything is accurate and to scale. It is absolutely correct hi every detail, having been approved by Naval Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown, and to make the engraving more readily understood all the features are shown in operative form, with Officers and Men in the act of performing the duties assigned to them in service con- ditions. This CHART IS REALLY AN ENCYCLOPEDIA OF .A SUBMARINE. It is educational and worth many times its cost. Mailed in a Tube for 25 cents CATALOGUE OF GOOD, PRACTICAL BOOKS BOX CAR CHART. A chart showing the anatomy of a box car, having every part of the car numbered and its proper name given in a reference list 20 cents GONDOLA CAR CHART. A chart showing the anatomy of a gondola car, having every part of the car numbered and its proper reference name given in a reference list 20 cents PASSENGER CAR CHART. A chart showing the anatomy of a passenger car, having every part of the car numbered and its proper name given in a reference list 20 cents WESTINGHOUSE AIR-BRAKE CHARTS. Chart I. Shows (in colors) the most modern Westinghouse High Speed and Signal Equip- ment used on Passenger Engines, Passenger Engine Tenders, and Passenger Cars. Chart II. Shows (in colors) the Standard Westinghouse Equipment for Freight and Switch En- gines, Freight and Switch Engine Tenders, and Freight Cars. Price for the set . 50 cents TRACTIVE POWER CHART. A chart whereby you can find the tractive power or drawbar pull of any locomotive, without making a figure. Shows what cylinders are equal, how driving wheels and steam pressure affect the power. What sized engine you need to exert a given drawbar pull or anything you desire in this line 50 cents HORSE POWER CHART. Shows the horse power of any stationary engine without calculation. No matter what the cylinder diameter of stroke; the steam pressure or cut-off; the revolutions, or whether con- densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- lations. Especially useful to engineers and designers ... 50 cents BOILER ROOM CHART. By GEO. L. FOWLER. A Chart size 14 x 28 inches showing in isometric perspective the mechanisms belonging in a modern boiler room. Water tube boilers, ordinary grates and mechanical stokers, feed water heaters and pumps comprise the equipment. The various parts are shown broken or removed, so that the internal construction is fully illustrated. Each part is given a reference number, and these, with the corresponding name, are given in a glossary printed at the sides. This chart is really a dictionary of the boiler room the names of more than 200 parts being given. It is educational worth many times its cost 25 cents CIVIL ENGINEERING HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED TRADES. Edited by JOSEPH G. HORNER, A. M. I. E. M. This set of five volumes contains about 2,500 pages with thousands of illustrations, including diagrammatic and sectional drawings with full explanatory details. This work covers the entire practice of Civil and Mechanical Engineering. The best known experts in all branches of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man, as well as the mechanical en- gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be found a means of advancement to any progressive man. It is encyclopedic in scope, thorough and practical in its treatment of technical subjects, simple and clear in its descriptive matter, and without unnecessary technicalities or formulae. The articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject, and are written by men who have had ample practical experience in the matters of which they write. It tells you all you want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot help but understand. As a work of reference it is without a peer. $6.00 per single volume. For complete set of five volumes, price $25. OC COKE COKE MODERN COKING PRACTICE; INCLUDING THE ANALYSIS OF MATERIALS AND PRODUCTS. By T. H. BYROM and J. E. CHRISTOPHER. A handbook for those engaged in Coke manufacture and the recovery of By-products. Fully illustrated with folding plates. It has been the aim of the authors, in preparing this book, to produce one which shall be of use and benefit to those who are associated with, or inter- ested in the modern developments of the industry. Contents: I. Introductory. II. Gen- CATALOGUE OF GOOD, PRACTICAL BOOKS eral Classification of Fuels. III. Coal Washing. IV. The Sampling and Valuation of Coal, Coke, etc. V. The Calorific Power of Coal and Coke. VI. Coke Ovens. VII. Coke Ovens, continued. VIII. Coke Ovens, continued. IX. Charging and Discharging of Coke Ovens, X. Cooling and Condensing Plant. XI. Gas Exhausters. XII. Composition and Analysis of Ammoniacal Liquor. XIII. Working-up of Ammoniacal Liquor. XIV. Treatment of Waste Gases from Sulphate Plants. XV. Valuation of Ammonium Sulphate. XVI. Direct Recovery of Ammonia from Coke Oven Gases. XVII. Surplus Gas from Coke Oven. Use- ful Tables. Very fully illustrated. Price $3. 50 net COMPRESSED AIR COMPRESSED AIR IN ALL ITS APPLICATIONS. By GARDNER D. Hiscox. This is the most complete book on the subject of Air that has ever been issued, and its thirty- five chapters include about every phase of the subject one can think of. It may be called an encyclopedia of compressed air. It is written by an expert, who. in its 665 pages, has dealt with the subject in a comprehensive manner, no phase of it being omitted. Includes the physical properties of air from a vacuum to its highest pressure, its thermodynamics, com- pression, transmission and uses as a motive power; in the Operation of Stationary and Port- able Machinery, in Mining. Air Tools, Air Lifts, Pumping of Water, Acids, and Oils; the Air Blast for Cleaning and Painting, the Sand Blast and its Work, and the Numerous Appli- ances in which Compressed Air is a Most Convenient and Economical Transmitter of Power for Mechanical Work, Railway Propulsion, Refrigeration, and the Various Uses to which Compressed Air has been applied. Includes forty-four tables of the physical properties of air, its compression, expansion, and volumes required for various kinds of work, and a list of patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, revised and enlarged. Cloth bound, $5.00. Half Morocco, price $6.60 CONCRETE ORNAMENTAL CONCRETE WITHOUT MOLDS. By A. A. HOUGHTON. The process for making ornamental concrete without molds has long been held as a secret, and now, for the first time, this process is given to the public. The book reveals the secret and is the only book published which explains a simple, practical method whereby the concrete worker is enabled, by employing wood and metal templates of different designs, to mold or model in concrete any Cornice, Archivolt, Column, Pedestal, Base Cap, Urn or Pier in a monolithic form right upon the job. These may be molded in units or blocks, and then built up to suit the specifications demanded. This work is fully illustrated, with detailed engravings. Price $2.00 CONCRETE FROM SAND MOLDS. By A. A. HOUGHTON. A Practical Work treating on a process which has heretofore been held as a trade secret by the few who possessed it, and which will successfully mold every and any class of ornamental concrete work. The process of molding concrete with sand molds is of the utmost practical value, possessing the manifold advantages of a low cost of molds, the ease and rapidity of operation, perfect details to all ornamental designs, density, and increased strength of the concrete, perfect curing of the work without attention and the easy removal of the molds re- gardless of any undercutting the design may have. 192 pages. Fully illustrated. Price $2.00 CONCRETE WALL FORMS. By A. A. HOUGHTON. A new automatic wall clamp is illustrated with working drawings. Other types of wall forms, clamps, separators, etc., are also illustrated and explained 50 cents CONCRETE FLOORS AND SIDEWALKS. By A. A. HOUGHTON. The molds for molding squares, hexagonal and many other styles of mosaic floor and side- walk blocks are fully illustrated and explained 50 cents PRACTICAL CONCRETE SILO CONSTRUCTION. By A. A. HOUGHTOX. Complete working drawings and specifications are given for several styles of concrete silos, with illustrations of molds for monolithic and block silos. The tables, data and information presented in this book are of the utmost value in planning and constructing all forms of concrete silos .... 50 cents MOLDING CONCRETE CHIMNEYS, SLATE AND ROOF TILES. By A. A. HOUGHTON. The manufacture of all types of concrete slate and roof tile is fully treated. Valuable data on all forms of reinforced concrete roofs are contained within its pages. The construction of concrete chimneys by block and monolithic systems is fully illustrated and described. A number of ornamental designs of chimney construction with molds are shown in this valu- able treatise - . . 50 cents CATALOGUE OF GOOD, PRACTICAL BOOKS MOLDING AND CURING ORNAMENTAL CONCRETE. By A. A. HOUGHTON. The proper proportions of cement and aggregates for various finishes, also the methods of thoroughly mixing and placing in the molds, are fully treated. An exhaustive treatise on this s ibjeci that every concrete worker will find of daily use and value 50 cents CONCRETE MONUMENTS, MAUSOLEUMS AND BURIAL VAULTS. By A. A. HOUGHTON. The molding of concrete monuments to imitate the most expensive cut stone is explained in this treatise, with working drawings of easily built molds. Cutting inscriptions and designs is also fully treated .50 cenis MOLDING CONCRETE BATH TUBS, AQUARIUMS AND NATATORIUMS. By A. A. HOUGHTON. Simple molds and instruction are given for molding many styles of concrete bath tubs, swimming pools, etc. These molds are easily built and permit rapid and successful work 50 cents CONCRETE BRIDGES, CULVERTS AND SEWERS. By A. A. HOUGHTON. A number of ornamental concrete bridges with illustrations of molds are given. A collapsible center or core for bridges, culverts and sewers is fully illustrated with detailed instructions for building 50 cents CONSTRUCTING CONCRETE PORCHES. By A. A. HOUGHTON. A number of designs with working drawings of molds are fully explained so any one can easily construct different styles of ornamental concrete porches without the purchase of expensive molds 50 cents MOLDING CONCRETE FLOWER POTS, BOXES, JARDINIERES, ETC. By A. A. HOUGHTON. The molds for producing many original designs of flower pots, urns, flower boxes, jardinieres, etc., are fully illustrated and explained, so the worker can easily construct and operate same 50 cents MOLDING CONCRETE FOUNTAINS AND LAWN ORNAMENTS. By A. A. HOUGHTON. The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun dials and other forms of ornamental concrete for the ornamentation of lawns and gardens, is fully illustrated and described 50 cents CONCRETE FOR THE FARM AND SHOP. By A. A. HOUGHTON. The molding of drain tile, tanks, cisterns, fence posts, stable floors, hog and poultry houses and all the purposes for which concrete is an invaluable aid to the farmer are numbered among the contents of this handy volume ; 50 cents POPULAR HANDBOOK FOR CEMENT AND CONCRETE USERS. By MYRON H. Lswis, This is a concise treatise of the principles and methods employed in the manufacture and use of cement in all classes of modern works. The author has brought together in this work all the salient matter of interest to the user of concrete and its many diversified products. The matter is presented in logical and systematic order, clearly written, fully illustrated and free from involved mathematics. Everything of value to the concrete user is given including kinds of cement employed in construction, concrete architecture, inspection and testing, water- proofing, coloring and painting, rules, tables, working, and cost data. The book comprises thirty-three chapters, as follows: Introductory. Kinds of Cements and How They are Made. Properties, Testing and Requirements of Hydraulic Cement. Concrete and its Properties. Sand, Broken Stone and Gravel for Concrete. How to Proportion the Materials. How to Mix and Place Concrete. Forms for Concrete Construction. The Architectural and Artistic Possibilities of Concrete. Concrete Residences. Mortars, Plasters and Stucco and How to Use Them. The Artistic Treatment of Concrete Surfaces. Concrete Building Blocks. The Making of Ornamental Concrete. Concrete Pipes, Fences, Posts, Etc. Essential Features and Advantages of Reen- forced Concrete. How to Design Reenforced Concrete Beams, Slabs and Columns. Ex- planations of the Methods and Principles in Designing Reenforced Concrete Beams and Slabs. Systems of Reenforcement Employed. Reenforced Concrete in Factory and General CATALOGUE OF GOOD. PRACTICAL BOOKS Building Construction. Concrete in Foundation Work. Concrete Retaining Walls, Abut- ments, and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder Bridges. Concrete in Sewerage and Drainage Works. Concrete Tanks, Dams and Reser- voirs. Concrete Sidewalks, Curbs and Pavements. Concrete in Railroad Constructions. The Utility of Concrete on the Farm. The Waterproofing of Concrete Structure. Grout or Liquid Concrete and Its Use. Inspection of Concrete Work. Cost of Concrete Work. Some of the special features of the book are: 1. The Attention Paid to the Artistic and Architectural Side of Concrete Work. 2. The Authoritative Treatment of the Problem of Waterproofing Concrete. 3. An Excellent Summary of the Rules to be Followed in Concrete Construction. 4. The Valuable Cost Data and Useful Tables given. A valuable Addition to the Library of Every Cement and Concrete User. Price $2.50 WATERPROOFING CONCRETE. By MYRON H. LEWIS. Modern Methods of Waterproofing Concrete and Other Structures. A condensed statement of the Principles, Rules, and Precautions to be Observed in Waterproofing and Damp- proofing Structures and Structural Materials. Paper binding. Illustrated. Price. .60 cents DICTIONARIES STANDARD ELECTRICAL DICTIONARY. By T. O'CoNOR SLOANE. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical hand-book of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progress of this branch of science. Complete, concise and convenient. 682 pages. 393 illustrations. Price .... $3.00 DIES METAL WORK DIES: THEIR CONSTRUCTION AND USE FOR THE MODERN WORKING OF SHEET METALS. By J. V. WOODWORTH. A most useful book, and one which should be in the hands of all engaged in the press working of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures and Devices, together with the manner in which they should be used in the Power Press, for the cheap and rapid production of the great variety of sheet metal articles now in use. It is designed as a guide to the production of sheet metal parts at the minimum of cost with the maximum of output. The hardening and tempering of Press tools and the classes of work which may be produced to the best advantage by the use of dies in the power press are fully treated. Its 505 illustrations show dies, press fixtures and sheet metal working devices, the descriptions of which are so clear and practical that all metal-working mechanics will be able to understand how to design, construct and use tliem. Many of the dies and press fixtures treated were either constructed by the author or under his supervision. Others were built by skilful raechanics and are in use in large sheet metal establishments and machine shops. Price $3.00 PUNCHES, DIES AND TOOLS FOR MANUFACTURING IN PRESSES. By J. V. WOODWORTH. This work is a companion volume to the author's elementary work entitled "Dies, Their Construction and Use." It does not go into the details of die making to the extent of the author's previous book, but gives a comprehensive review of the field of operations carried on by presses. A large part of the information given has been drawn from the author's personal experience. It might well be termed an Encycl9pedia of Die Making, Punch Making, Die Sinking, Sheet Metal Working, and Making of Special Tools, Sub-presses, Devices and Mechani- cal Combinations for Punching, Cutting, Bending, Forming, Piercing, Drawing, Compressing and Assembling Sheet Metal Parts, and also Articles of other Materials in Machine Tools. 2d Edition. Price $4.00 DROP FORGING, DIE SINKING AND MACHINE FORMING OF STEEL. By J. V. WOODWORTH. This is a practical treatise on Modernr Shop Practice, Processes, Methods, Machines, Tools, and Details, treating on the Hot and Cold Machine- Forming of Steel and Iron into Finished shapes; Together with Tools, Dies, and Machinery involved in the manufacture of Duplicate CATALOGUE OF GOOD, PRACTICAL BOOKS Forgings and Interchangeable Hot and Cold Pressed Parts from Bar and Sheet Metal. This book fills a demand of long standing for information regarding drop forging, die-sinking and machine forming of steel and the shop practice involved, as it actually exists in the modern drop forging shop. The processes of die-sinking and force-making, which are thor- oughly described and illustrated in this admirable work, are rarely to be found explained in s ich a clear and concise manner as is here set forth. The process of die-sinking relates to the engraving or sinking of the female or lower dies, such as are used for drop forgings, hot and cold machine forging, swedging and the press working of metals. The process of force- making relates to the engraving or raising of the male or upper dies used in producing the lower dies for the press-forming and machine-forging of duplicate parts of metal. Tn addition to the arts above mentioned the book contains explicit information regarding the drop forging and hardening plants, designs, conditions, equipment, drop hammers, forging machines, etc., machine forging, hydraulic forging, autogenous welding and shop practice. The book contains eleven chapters, and the information contained in these chapters is just what will prove most valuable to the forged metal worker. All operations described in the work are thoroughly illustrated by means of perspective half-tones and outline sketches of the machinery employed. 300 detailed illustrations. Price $2.50 DRAWING SKETCHING PAPER LINEAR PERSPECTIVE SELF-TAUGHT. By HERMAN T. C. KRAUS. This work gives the theory and practice of linear perspective, as used in architectural, engi- neering, and mechanical drawings. Persons taking up the study of the subject by themselves will be able by the use of the instruction given to readily grasp the subject, and by reason- able practice become good perspective draftsmen. The arrangement of the book is good ; the plate is on the left-hand, while the descriptive text follows on the opposite page, so as to be readily referred to. The drawings are on sufficiently large scale to show the work clearly and are plainly figured. The whole work makes a very complete course on perspective draw- ing, and will be found of great value to architects, civil and mechanical engineers, patent attorneys, art designers, engravers, and draftsmen $2.50 PRACTICAL PERSPECTIVE. By RICHARDS and COLVIN. Shows just how to make all kinds of mechanical drawings in the only practical perspective isometric. Makes everything plain so that any mechanic can understand a sketch or drawing in this way. Saves time in the drawing room, and mistakes in the shops. Contains practical examples of various classes of work. 3rd Edition 50 cents SELF-TAUGHT MECHANICAL DRAWING AND ELEMENTARY MACHINE DESIGN. By F- L. SYLVESTER, M.E., Draftsman, with additions by ERIK OBERG, associate editor of "Machinery." This is a practical treatise on Mechanical Drawing and Machine Design, comprising the first principles of geometric and mechanical drawing, workshop mathematics, mechanics, strength of materials and the calculations and design of machine details. The author's aim has been to adapt this treatise to the requirements of the practical mechanic and young draftsman and to present the matter in as clear and concise a manner as possible. To meet the demands of this class of students, practically all the important elements of machine design have been dealt with, and in addition algebraic formulas have been explained, and the elements of trigonometry treated in the manner best suited to the needs of the prac- tical man. The book is divided into 20 chapters, and in arranging the material, mechan- ical drawing, pure and simple, has been taken up first, as a thorough understanding of the principles of representing objects facilitates the further study of mechanical subjects. This is followed by the mathematics necessary for the solution of the problems in machine de- sign which are presented later, and a practical introduction to theoretical mechanics and the strength of materials. The various elements entering into machine design, such as cams, gears, sprocket wheels, cone pulleys, bolts, screws, couplings, clutches, shafting and fly- wheels have been treated in such a way as to make possible the use of the work as a text- book for a continuous course of study. It is easily comprehended and assimilated even by students of limited previous training. 330 pages, 215 engravings. Price. . . . $2.00 A NEW SKETCHING PAPER. A new specially ruled paper to enable you to make sketches or drawings in isometric perspective without any figuring or fussing. It is being used for shop details as well as for assembly drawings, as it makes one sketch do the work of three, and no workman can help seeing jus! what is wanted. Pads of 40 sheets, 6x9 inches, 25 cents. Pads of 40 sheets, 9 x 12 inches 50 cents; 40 sheets, 12x18, Price $1.00 8 CATALOGUE OF GOOD, PRACTICAL BOOKS ELECTRICITY ARITHMETIC OF ELECTRICITY. By Prof. T. O'CoNOR SLOANE. A practical treatise on electrical calculations of all kinds reduced to a series of rules, all of the simplest forms, and involving only ordinary arithmetic; each rule illustrated by one or more practical problems, with detailed solution of each one. This book is classed among the most useful works published on the science of electricity covering as it does the mathematics of electricity in a manner that will attract the attention of those who are not familiar with alge- braical formulas. 20th Edition. 160 pages. Price $1.00 COMMUTATOR CONSTRUCTION. By WM. BAXTER, JR. The business end of any dynamo or motor of the direct current type is the commutator. This book goes into the designing, building, and maintenance of commutators, shows how to locate troubles and how to remedy them; everyone who fusses with dynamos needs this. 85 cents DYNAMO BUILDING FOR AMATEURS, OR HOW TO CONSTRUCT A FIFTY-WATT DYNAMO. By ARTHUR J. WEED, Member of N. Y. Electrical Society. A practical treatise showing in detail the construction of a small dynamo or motor, the entire machine work of which can be done on a small foot lathe. Dimensioned working drawings are given for each piece of machine work and each operation is clearly described. This machine, when used as a dynamo, has an output of fifty watts; when used as a motor it will drive a small drill press or lathe. It can be used to drive a sewing machine on any and all ordinary work. The book is illustrated with more than sixty original engravings showing the actual construction of the different parts. Among the contents are chapters on 1 . Fifty Watt Dynamo. 2. Side Bearing Rods. 3. Field Punchings. 4. Bearings. 5. Commu- tator. 6. Pulley. 7. Brush Holders. 8. Connection Board. 9. Armature Shaft. 10. Armature. 11. Armature Winding. 12. Field Winding. 13. Connecting and Starting. Price, paper, 50 cents. Cloth $1.00 ELECTRIC FURNACES AND THEIR INDUSTRIAL APPLICATIONS. By J. WRIGHT This is a book which will prove of interest to many classes of people; the manufacturer who desires to know what product can be manufactured successfully in the electric furnace, the chemist who \yishes to post himself on the electro-chemistry, and the student of science who merely looks into the subject from curiosity. The book is not so scientific as to be of use pnly to the technologist, nor so unscientific as to suit only the tyro in electro-chemistry; it is a practical treatise of what has been done, and of what is being done, both experimentally and commercially with the electric fifrnace. In important processes not only are the chemical equations given, but complete thermal data are set forth and both the efficiency of the furnace and the cost of the product are worked out, thus giving the work a solid commercial value aside from its efficacy as a work of reference. The practical features of furnace building are given the space that the subject deserves. The forms and refractory materials used in the linings, the arrangement of the connections to the electrodes, and other important details are explained. 288 pages. New Revised Edition. Fully illustrated. Price $3.00 ELECTRIC LIGHTING AND HEATING POCKET BOOK. By SYDNEY F. WALKER. This book puts in convenient form useful information regarding the apparatus which is likely to be attached to the mains of an electrical company. Tables of units and equivalents are included and useful electrical laws and formulas are stated. One section is devoted to dynamos, motors, transformers and accessory apparatus; another to accumulators, another to switchboards and related equipment, a fourth to a description of various systems of distribution, a fifth section to a discussion of instruments, both for portable use and switchboards; another section deals with electric lamps of various types and accessory appliances, and the concluding section is given up to electric heating apparatus. In each section a large number of commercial types are described, frequent tables of dimen- sions being included. A great deal of detail information of each line of apparatus is given and the illustrations shown give a good idea of the general appearance of the apparatus under discussion. The book also contains much valuable information for the central station engi- neer. 438 pages. 300 engravings. Bound in leather pocket book form. Price . $3.00 ELECTRIC WIRING, DIAGRAMS AND SWITCHBOARDS. By NEWTON HARRISON. \ thoroughly practical treatise covering the subject of Electric Wiring in all its branches, including explanations and diagrams which are thoroughly explicit and greatly simplify the subject. Practical every-day problems in wiring are presented and the method of obtaining intelligent results clearly shown. Only arithmetic is used. Ohm's law is given CATALOGUE OF GOOD, PRACTICAL BOOKS a simple explanation with reference to wiring for direct and alternating currents. The funda- mental principle of drop of potential in circuits is shown with its various applications The simple circuit is developed with the position of mains, feeders and branches; their treat- ment as a part of a wiring plan and their employment in house-wiring clearly illustrated Some simple facts about testing are included in connection with the wiring. Molding and conduit work are given careful consideration; and switchboards are systematically treated, built up and illustrated, showing the purpose they serve, for connection with tho circuits, and to shunt and compound wound machines. The simple principles of switchboard construction, the development of the switchboard, the connections of the various instru- ments including the lightning arrester, are also plainly set forth. Alternating current wiring is treated, with explanations of the power factor, conditions calling for various sizes of wire and a simple way of obtaining the sizes for single-phase, two- phase and three-phase circuits. This is the only complete work issued showing and telling you what you should know about direct and alternating current wiring. It is a ready refer- ence. The work is free from advanced technicalities and mathematics, arithmetic being used throughout. It is in every respect a handy, well-written, instructive, comprehensive volume on wiring for the wireman, foreman, contractor, or electrician. 272 pages; 105 illus- trations. Price $1.50 ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTR T C MOTOR CON- STRUCTION. By Prof. T. O'CoNOR SLOANE. This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos and instruments in general, and is designed to bring within the reach of young and old the manufacture of genuine and useful electrical appliances. The work is especially designed for amateurs and young folks. Thousands of our young people are daily experimenting, and busily engaged in making electrical toys and apparatus of various kinds. The present work is just what is wanted to give the much needed information in a plain, practical manner, with illustrations to make easy the carrying out of the work. 19th Edition. Price $1.00 ELECTRICIAN'S HANDY BOOK. By Prof. T. O'CoNOR SLOANE. This work of 768 pages is intended for the practical electrician who has to make things go. The entire field of electricity is covered within its pages. Among some of the subjects treated are: The Theory of the Electric Current and Circuit, Elect ro-Chemistry, Primary Batteries, Storage Batteries, Generation and Utilization of Electric Powers, Alternating Current, Arma- ture Winding, Dynamos and Motors, Motor Generators, Operation of the Central Station Switchboards, Safety Appliances, Distribution of Electric Light and Power, Street Mains, Transformers, Arc and Incandescent Lighting, Electric Measurements, Photometry, Electric Railways, Telephony, Bell-Wiring, Electro-Plating, Electee Heating, V/ireless Telegraphy, etc. It contains no useless theory; everything is to the point. It teaches you just what you want to know about electricity. It is the standard work published on the subject. Forty-9ne chapters, 610 engravings, handsomely bound in red leather with title and edges in gold. Price: $3.50 ELECTRICITY IN FACTORIES AND WORKSHOPS, ITS COST AND CONVENIENCE. By ARTHUR P. HASLAM. A practical book for power producers and power users showing what a convenience the electric motor, in its various forms, has become to the modern manufacturer. It also deals with the conditions which determine the cost of electric driving, and compares this with other methods of producing and utilizing power. Among the chapters contained in the book are: The Direct Current Motor; The Alternating Current Motor; The Starting and Speed Regulation of Electric Motors; The Rating and Efficiency of Electric Motors; The Cost of Energy as Affected by Conditions of Working, The Question for the Small Power User; Independent Generating Plants; Oil and Gas Engine Plants; Steam Plants; Power Station Tariffs; The Use of Electric Power in Textile Factories; Electric Power in Printing Works; The Use of Electric Power in Engineering Workshops Miscellaneous Application of Electric Power; The Installation of Electric Motors; The Lighting of Industrial Establishments. 312 pages. Very fully illustrated. Price .... $3.50 ELECTRICITY SIMPLIFIED. By Prof. T. O'CoNOR SLOANE. The object of "Electricity Simplified " is to make the subject as plain as possible and to show what the modern conception of electricity is; to show how two plates of different metals immersed in acid can send a message around the globe; to explain how a bundle of copper wire rotated by a steam engine can be the agent in lighting our streets, to tell what the volt, ohm and ampere are, and what high and low tension mean; and to answer the questions that perpetually arise in the mind in this age of electricity. 172 pages. Illustrated. Price $ 1.00 IO CATALOGUE OF GOOD, PRACTICAL BOOKS HOUSE WIRING. By THOMAS W. POPPE. This work describes and illustrates the actual installation of Electric Light Wiring, the manner in which the work should be done, and the method of doing it. The book can be conveniently carried in the pocket. It is intended for the Electrician, Helper and Apprentice. It solves all Wiring Problems, and contains nothing that conflicts with the rulings of the Nation- al Board of Fire Underwriters. It gives just the information essential to the Successful Wiring of a Building. Among the subjects treated are: Locating the Meter. Panel Boards. Switches. Plug Receptacles. Brackets. Ceiling Fixtures. The Meter Connections. The Feed Wires. The Steel Armored Cable System. The Flexible Steel Conduit System. The Ridig Conduit System. A digest of the National Board of Fire Underwriters' rules relating to metallic wiring systems. Various switching arrangements explained and diagrammed. The easiest method of testing the Three and Four- way circuits explained. The grounding of all metallic wiring systems and the reason for doing so shown and explained. The in- sulation of the metal parts of lamp fixtures and the reason for the same described and illustrated. 125 pages. Fully illustrated. Flexible cloth. Price 50 cents HOW TO BECOME A SUCCESSFUL ELECTRICIAN. By Prof. T. O'CoNOR SLOANE. Every young man who wishes to become a successful electrician should read this book. It tells in simple language the surest and easiest way to become a successful electrician. The studies to be followed, methods of work, field of operation and the requirements of the successful electrician are pointed out and fully explained. Every young engineer will find this an ex- cellent stepping-stone to more advanced works on electricity which he must master before success can be attained. Many young men become discouraged at the very outstart by attempting to read and study books that are far beyond their comprehension. This book serves as the connecting link between the rudiments taught in the public schools and the real study of electricity. It is interesting from cover to cover. Fifteenth edition. 202 pages. Illustrated. Price $1.00 MANAGEMENT OF DYNAMOS. By LUMMIS-PATERSON. A handbook of theory and practice. This work is arranged in three parts. The first part covers the elementary theory of the dynamo. The second part, the construction and action of the different classes of dynamos in common use are described; while the third part relates to such matters as affect the practical management and working of dynamos and motors The following chapters are contained in the book: Electrical Units; Magnetic Principles; Theory of the Dynamo; Armature; Armature in Practice; Field Magnets; Field Magnets in Practice; Regulating Dynamos; Coupling Dynamos; Installation, Running, and Maintenance of Dynamos; Faults in Dynamos; Faults in Armatures; Motors. 292 pages. 117 illustra- tions. Price $1.50 STANDARD ELECTRICAL DICTIONARY. By T. O'CONOR SLOANE. An indispensable work to all interested in electrical science. Suitable alike for the student and professional. A practical hand-book of reference containing definitions of about 5,000 distinct words, terms and phrases. The definitions are terse and concise and include every term used in electrical science. Recently issued. An entirely new edition. Should be in the possession of all who desire to keep abreast with the progesss of this branch of science. In its arrangement and typography the book is very convenient. The word or term defined is printed in black-faced type which readily catches the eye, while the body of the page is in smaller but distinct type. The definitions are well worded, and so as to be understood by the non-technical reader. The general plan seems to be to give an exact, concise definition, and then amplify and explain in a more popular way. Synonyms are also given, and refer- ences to other words and phrases are made. A very complete and accurate index of fifty pages is at the end of the volume; and as this index contains all synonyms, and as all phrases are indexed in every reasonable combination of words, reference to the proper place in the body of the book is readily made. It is difficult to decide how far a book of this character is to keep the dictionary form, and to what extent it may assume the encyclopedia form. For some purposes, concise, exactly worded definitions are needed; for other purposes, more extended descriptions are required. This book seeks to satisfy both demands, and does it with considerable success. Complete, concise, and convenient. 682 pages. 393 illustra- tions. Twelfth edition. Price $3.00 SWITCHBOARDS. By WILLIAM BAXTER, JR. This book appeals to every engineer and electrician who wants to know the practical side of things. It takes up all sorts and conditions of dynamos, connections and circuits and shows by diagram and illustration just how the switchboard should be connected. Includes direct and alternating current boards, also those for arc lighting, incandescent, and power circuits. Special treatment on high voltage boards for power transmission. 2d Edition. 190 pages. Illustrated, Price $1.50 IX CATALOGUE OF GOOD, PRACTICAL BOOKS TELEPHONE CONSTRUCTION, INSTALLATION, WIRING, OPERATION AND MAINTENANCE. By W. H. RADCLIFFE and H. C. GUSHING. This book gives the principles of construction gnd operation of both the Bell and Independent instruments; approved methods of installing and wiring them; the means of protecting them from lightning and abnormal currents; their connection together for operation as series or bridging stations; and rules for their inspection and maintenance. Line wiring and the wir- ing and operation of special telephone systems are also treated. Intricate mathematics are avoided, and all apparatus, circuits and systems are thoroughly described. The appendix contains definitions of units and terms used in the text. Selected wiring tables, which are very helpful, are also included. Among the subjects treated are Construction, Operation, and installation of Telephone Instruments, Inspection and Main- tenance of Telephone Instruments; Telephone Line Wiring; Testing Telephone Line "Wires and Cables; Wiring and Operation of Special Telephone Systems, etc. 100 pages, 125 illus- trations $1.00 WIRELESS TELEGRAPHY AND TELEPHONY SIMPLY EXPLAINED. BY ALFRED P. MORGAN. This is undoubtedly one of the most complete and comprehensible treatises on the subject ever published, and a close study of its pages will enable one to master all the details of the wireless transmission of messages. The author has filled a long felt want and has succeeded in furnishing a lucid, comprehensible explanation in simple language of the theory and practice of wireless telegraphy and telephony. Among the contents are: Introductory; Wireless Transmission and Reception The Aerial System, Earth Connections The Transmitting Apparatus, Spark Coils and Trans- formers, Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches The Receiving Apparatus, Detectors, etc. Tuning and Coupling, Tuning Coils, Loose Couplers, Variable Condensers, Directive Wave Systems Miscellaneous Apparatus, Telephone Receivers, Range of Stations. Static, Interference Wireless Telephones, Sound and Sound Waves, The Vocal Cords and Ear Wireless Telephones, How Sounds are changed into Electric Waves Wireless Telephones, The Apparatus Summary. 200 pages. 150 engravings. Price $1.00 WIRELESS TELEPHONES AND HOW THEY WORK. By JAMES ERSKINE-MURRA Y. This work is free from elaborate details and aims at giving a clear survey of the way in which Wireless Telephones work. It is intended for amateur workers and for those whose knowledge of electricity is slight. Chapters contained: How We Hear; Historical; The Conversion of Sound into Electric Waves; Wireless Transmission; The Production of Alternating Currents of High Frequency; How the Electric Waves are Radiated and Received; The Receiving Instruments; Detectors; Achievements and Expectations; Glossary of Technical Words, Cloth. Price SI. 00 WIRING A HOUSE. By HERBERT PRATT. Shows a house already built; tells just how to start about wiring it; where to begin; what wire to use; how to run it according to Insurance Rules; in fact just the information you need. Directions apply equally to a shop. Fourth edition 25 cents FACTORY MANAGEMENT, ETC. MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. By O. E. PERRIGO, M.E. The only work published that describes the modern machine shop or manufacturing plant from the time the grass is growing on the site intended for it until the finished product is shipped. By a careful study of its thirty-two chapters the practical man may economically build, efficiently equip, and successfully manage the modern machine shop or manufacturing estab- ishment. Just the book needed by those contemplating the erection of modern shop buildings, the re-building and re-organization of old ones, or the introduction of modern shop methods, time and cost system. It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts. It is the most complete all around book of its kind ever published. It is a practical book for practical men, from the apprentice in the shop to the president iii the office. It minutely describes and illustrates the most simple and yet the most efficient time and cost system yet devised. Price $5.00 12 CATALOGUE OF GOOD, PRACTICAL BOOKS FUEL COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By WM. M. BARR. This book has been prepared with special reference to the generation of heat by the combus- tion of the common fuels found in the United States, and deals particularly with the condi- tions necessary to the economic and smokeless combustion of bituminous coals in Stationary and Locomotive Steam Boilers. The presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language, free from technicalities, the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods for furnace construction for obtaining the great- est quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price ,4 $1.00 SMOKE PREVENTION AND FUEL ECONOMY. By BOOTH and KERSHAW. A complete treatise for all interested in smoke prevention and combustion, being based on the German work of Ernst Schmatolla, but it is more than a mere translation of the German treatise, much being added. The authors show as briefly as possible the principles of fuel combustion, the methods which have been and are at present in use, as well as the proper scientific methods for obtaining all the energy in the coal and burning it without smoke. Considerable space is also given to the examination of the waste gases, and several of the representative English and American mechanical stoker and similar appliances are described. The losses carried away in the waste gases are thoroughly analyzed and discussed in the Ap- pendix, and abstracts are also here given of various patents on combustion apparatus. The book is complete and contains much of value to all who have charge of large plants. 194 pages. Illustrated. Price $2.50 GAS ENGINES AND GAS GASOLINE ENGINES : THEIR OPERATION, USE AND CARE. By A. HYATT VERRILL. The Simplest, Latest and Most Comprehensive popular work published on Gasoline Engines describing what the Gasoline engine is; its construction and operation ; how to install it; how to select it; how to use it and how to remedy troubles encountered. Intended for owners. Operators and Users of Gasoline Motors of all kinds. This work fully describes and illus- trates the various types of Gasoline engines used in Motor Boats, Motor Vehicles and Stationary Work. The parts, accessories and Appliances are described, with chapters on ignition, fuel, lubrication, operation and engine troubles. Special attention is given to the care, operation and repair of motors with useful hints and suggestions on emergency re- pairs and make-shifts. A complete glossary of technical terms and an alphabetically ar- ranged table of troubles and their symptoms form most valuable and unique features of this manual. Nearly every illustration in the book is original, having been made by the author. Every page is full of interest and value. A book which you cannot afford to be without. 320 pages. Nearly 150 specially made engravings. Price $1.50 GAS, GASOLINE, AND OIL ENGINES. By GARDNER D. Hiscox. Just issued, 20th revised and enlarged edition. Every user of a gas engine needs this book. Simple, instructive, and right up-to-date. The only complete work on the subject. Tells all about the running and management of gas, gasoline and oil engines, as designed and manu- factured in the United States. Explosive motors for stationary, marine and vehicle power are fully treated, together with illustrations of their parts and tabulated sizes, also their care and running are included. Electric ignition by induction coil and jump spark are fully explained and illustrated, including valuable information on the testing for economy and power and the erection of power plants. The rules and regulations of the Board of Fire Underwriters in regard to the installation an1 management of gasoline motors is given in full, suggesting the safe installation of explosive motor power. A list of United States Patents issued on gas, gasoline, and oil engines and their adjuncts from 1875 to date is included. 484 pages. 410 engravings Price . . . $2.50 MODERN GAS ENGINES AND PRODUCER GAS PLANTS. By R. E. MATHOT, M.E. A guide for the gas engine designer, user, and engineer in the construction, selection, purchase installation, operation, and maintenance of gas engines. More than one book on gas engines has been written, but not one has thus far even encroached on the field covered by this book. Above all Mr. Mathot's work is a practical guide. Recognizing the need of a volume that '3 CATALOGUE OF GOOD, PRACTICAL BOOKS would assist the gas engine user in understanding thoroughly the motor upon which he depends for power, the author has discussed his subject without the help of any mathematics and without elaborate theoretical explanations. Every part of the gas engine is described in detail, tersely, clearly, with a thorough understanding of the requirements of the mechanic. Helpful suggestions as to the purchase of an engine, its installation, care, and operation form a most valuable feature of the work. 320 pages. 175 detailed illustrations. Price . . . $2.50 GAS ENGINE CONSTRUCTION, OR HOW TO BUILD A HALF-HORSE-POWER GAS ENGINE. By PARSELL and WEED. A practical treatise of 300 pages describing the thepry and principles of the action of Gas Engines of various types and the design and construction of a half-horse power Gas Engine, with illustrations of the work in actual progress, together with the dimensioned working drawings giving clearly the sizes of the various details; for the student, the scientific investigator and the amateur mechanic. Tnis book treats of the subject more from the standpoint of practice than that of theory. The principles of operation of Gas Engines are clearly and simply described and then the actual construction of a half-horse power engine is taken up, step by step, showing in detail the making of the Gas Engine. 3d Edition. 300 pages. Price ........... $2.50 THE GASOLINE ENGINE ON THE FARM: ITS OPERATION, REPAIR AND USES. By XENO W. PUTNAM. This is a practical treatise on the Gasoline and Kerosene engine intended for the man who wants to know just how to manage his engine and how to apply it to all kinds of farm work to the best advantage. The book includes selecting the most suitable engine for farm work, its most convenient and efficient installation, with chapters on troubles, their remedies and how to avoid them. The care and management of the farm tractor in plowing, harrowing, harvesting and road grading are fully covered; also plain directions are given for handling the tractor on the road. Special attention is given to relieving farm life of its drudgery by applying power to the disagreeable small tasks which must otherwise be done by hand. Many homemade con- trivances for cutting wood, supplying kitchen, garden and barn with water, loading, hauling and unloading hay, delivering grain to the bins or the feed trough are included; also full directions for making the engine milk the cows, churn, wash, sweep the house and clean the windows, etc. Very fully illustrated with drawings of working parts and cuts showing Stationary, Portable and Tractor Engines doing all kinds of farm work. 300 pages-. Nearly 150 engravings. 12mo. Price ................. $1.50 CHEMISTRY OF GAS MANUFACTURE. By H. M. ROYLES. This book covers points likely to arise in the ordinary course of the duties of the engineer or manager of a gas works not large enough to necessitate the employment of a separate chemical loyed in the manufacture of illuminat- staff. It treats of the testing of the raw materials empl ing coal gas, and of the gas produced. The preparation of standard solutions is given as well as the chemical and physical examination of gas coal including among its contents Prepa- rations of Standard Solutions, Coal, Furnaces, Testing and Regulati9n. Products of Car- bonization. Analysis of Crude Coal Gas. Analysis of Lime. Ammonia. Analysis of Oxide of Iron. Naphthalene. Analysis of Fire-Bricks and Fire-Clay. Weldom and Spent Oxide. Photometry and Gas Testing. Carburetted Water Gas. Metropolis Gas. Miscellaneous Extracts. Useful Tables .................... $4.50 GEARING AND CAMS BEVEL GEAR TABLES. By D. AG. ENGSTROM. A book that will at once commend itself to mechanics and draftsmen. Does away with all the trigonometry and fancy figuring on bevel gears and makes it easy for anyone to lay them out or make them just right. There are 36 full-page tables that show every necessary dimen- sion for all sizes or combinations you're apt to need. No puzzling figuring or guessing. Gives placing distance, all the angles (including cutting angles), and the correct cutter to use. A copy of this prepares you for anything in the bevel gear line. 66 pages. . $1.00 CHANGE GEAR DEVICES. By OSCAR E. PERRIGO. A practical book for every designer, draftsman, and mechanic interested in the invention and development of the devices for feed changes on the different machines requiring such mechan- ism. All the necessary information on this subject is taken up, analyzed, classified, sifted, and concentrated for the use of busy men who have not the time to go through the masses of irrelevant matter with which such a subject is usually encumbered and select such infor- mation as will be useful to them. It shows just what has been done, how it has been done, when it was done, and who did it. It saves time in hunting up patent records and re-inventing old ideas. 88 pages. $1.00 CATALOGUE OF GOOD. PRACTICAL BOOKS DRAFTING OF CAMS. By Louis ROUILLION. The laying out of cams is a serious problem unless you know how to go at it right. This puts you on the right road for practically any kind of cam you are likely to run up against. 25 cents HYDRAULICS HYDRAULIC ENGINEERING. By GARDNER D. Hiscox. A treatise on the properties, power, and resources of water for all purposes. Including the measurement of streams, the flow of water in pipes or conduits; the horse-power of falling water; turbine and impact water-wheels, wave motors, centrifugal, reciprocating, and air- lift pumps. With 300 figures and diagrams and 36 practical tables. All who are interested in water-works development will find this book a useful one, because it is an entirely practical treatise upon a subject of present importance, and cannot fail in having a far-reaching influence, and for this reason should have a place in the working library of every engineer. Among the subjects treated are: Historical Hydraulics, Properties of Water; Measurement of the flow of Streams; Flow from Subsurface orifices and nozzles; Flow of water in Pipes; Siphons of various kinds; Dams and Great Storage Reservoirs; City and Town Water Supply; Wells and their reenforcement ; Air lift methods of raising water ; artesian wells ; Irrigation of Arid districts ; Water Power, Water Wheels ; Pumps and Pumping Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic Mining; Canals; Ditches; Conduits and Pipe Lines; Marine Hydraulics; Tidal and Sea Wave power, etc. 320 pages. Price $4.00 ICE AND REFRIGERATION POCKET BOOK OF REFRIGERATION AND ICE MAKING. By A. J. WALLIS- TAYLOR. This is one of the latest and most comprehensive reference books published on the subject of refrigeration and cold storage. It explains the properties and refrigerating effect of the different fluids in use, the management of refrigerating machinery and the construction and insulation of cold rooms with their required pipe surface for different degrees of cold ; freezing mixtures and non-freezing brines, temperatures of cold rooms for all kinds of provisions, cold storage charges for all classes of goods, ice making and storage of ice, data and memoranda for constant reference by refrigerating engineers, with nearly one hundred tables containing valuable references to every fact and condition required in the installment and operation of a refrigerat- ing plant. Illustrated. (5th Edition, revissd.) Price $1,50 INVENTIONS PATENTS INVENTOR'S MANUAL, HOW TO MAKE A PATENT PAY. This is a book designed as a guide to inventors in perfecting their inventions, taking out their patents and disposing of them. It is not in any sense a Patent Solicitor's Circular, nor a Patent Broker's Advertisement. No advertisements of any description appear in the work. It is a book containing a quarter of a century's experience of a successful inventor, together with notes based upon the experience of many other inventors. Among the subjects treated in this work are: How to Invent. How to Secure a Good Patent. Value of Good Invention. How to exhibit an Invention. How to Interest Capital. How to Estimate the Value of a Patent. Value of Design Patents. Value of Foreign Patents. Value of Small Inventions. Advice on Selling Patents. Advice on the Formation of Stock Companies. Advice on the Formation of Limited Liability Companies. Advice on Disposing of Old Patents. Advice as to Patent Attorneys. Advice as to Selling Agents. Forms of Assignments. License and Contracts. State Laws Concerning Patent Rights. 1900 Census of the United States by counties of over 10,000 population. Revised edition. 120 pages. Price $1.00 KNOTS KNOTS, SPLICES AND ROPE WORK. By A. HYATT VEREILL. This is a practical book giving complete and simple directions for making all the most use- ful and ornamental knots in common use. with chapters on Splicing, Pointing, Seizing, CATALOGUE OF GOOD, PRACTICAL BOOKS Serving, etc. This book is fully illustrated with one hundred and fifty original engravings, which show how each knot, tie or splice is formed and its appearance when finished. The book will be found of the greatest value to Campers, Yachtsmen, Travelers, Boy Scouts, in fact to anyone having occasion to use or handle rope or knots for any purpose. The book is thoroughly reliable and practical and is not only a guide but a teacher. It is the standard work on the subject. Among the contents are: 1. Cordage, Kinds of Rope. Construction of Rope, Parts of Rope Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Sim- ple knots and Bends. Terms used in Handling Rope. Seizing Rope. 3. Ties and Hitches. 4. Noose, Loops and Mooring Knots. 5. Shortenings, Grommets and Selvages. 6. Lash- ings. Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages. 150 original engravings. Price 60 cents LATHE WORK MODERN AMERICAN LATHE PRACTICE. By OSCAR E. PERRIGO. This is a new book from cover to cover, and the only complete American work on the subject written by a man who knows not only how work ought to be done, but who also knows how to do it, and how to convey this knowledge to others. It is strictly up-to-date in its descriptions and illustrations, which represent the very latest practice in lathe and boring mill operations as well as the construction of and latest developments in the manufacture of these important classes of machine tools. Lathe history and the relations of the Lathe to manufacturing are given; also a description of the various devices for Feeds and Thread Cutting mechanisms from early efforts in this direction to the present time. Lathe design is thoroughly discussed, including Back Gearing, Driving Cones, Thread Cutting Gears, and all the essential elements of the modern Lathe. The classification of Lathes is taken up, giving the essential differences of the several types of Lathes, including, as is usually understood, Engine Lathes, Bench Lathes, Speed Lathes. Forge Lathes, Gap Lathes, Pulley Lathes, Forming loathes, Multiple Spindle Lathes, Rapid Reduction Lathes, Precision Lathes, Turret Lathes, Special Lathes, Electrically Driven Lathes, etc. 424 pages. 314 illustrations. Price $2.50 PRACTICAL METAL TURNING. By JOSEPH G. HORNER. This important and practical subject is treated in a full and exhaustive manner and nothing of importance is omitted. The principles and practice and all the different branches of Turn- ing are considered and well illustrated. All the different kinds of Chucks of usual forms, as well as some unusual kinds, are shown. A feature of the book is the important section de- voted to modern Turret practice; Boring is another subject which is treated fully; and the chapter on Tool Holders illustrates a large number of representative types. Thread Cutting is treated at reasonable length; and the last chapter contains a good deal of information relating to the High-Speed Steels and their work. The numerous tools used by machinists are illustrated, and also the aujuncts of the lathe. In fact, the entire subject is treated in such a thorough manner as to make this book the standard one on the subject. It is indis- pensable to the manager, engineer, and machinist as well as to the student, amateur, and experimental, man who desires to keep up-to-date. 400 pages, fully illustrated. Price $3.50 TURNING AND BORING TAPERS. By FRED H. COLVIN. There are two ways to turn tapers; the right way and one other. This treatise has to do with the right way; it tells you how to start the work properly, how to set the lathe, what tools to use and how to use them, and forty and one other little things that you should know. Fourth edition 25 cent* LIQUID AIR LIQUID AIR AND THE LIQUEFACTION OF GASES. By T. O'CoNOR SLOANE. This book gives the history of the theory, discovery, and manufacture of Liquid Air, and contains an illustrated description of all the experiments that have excited the wonder of audiences all over the country. It shows how liquid air, like water, is carried hundreds of miles and is handled in open buckets. It tells what may be expected from it in the near future. A book that renders simple one of the most perplexing chemical problems of the century. Startling developments illustrated by actual experiments. It is not only a work of scientific interest and authority, but is intended for the general reader, being written in a popular style easily understood by every one. Second edition. 365 <>Q Price $2.OO 16 CATALOGUE OF GOOD, PRACTICAL BOOKS LOCOMOTIVE ENGINEERING AIR-BRAKE CATECHISM. By ROBERT H. BLACKALL. This book is a standard text book. It covers the Westinghouse Air-Brake Equipment, in- cluding the No. 5 and the Np. 6 E. T Locomotive Brake Equipment ; the K (Quick-Service) Triple Valve for Freight Service; and the Cross-Compound Pump. The operation of all parts of the apparatus is explained in detail, and a practical way of finding their peculiarities and defects, with a proper remedy, is given. It contains 2,000 questions with their answers, which will enable any railroad man to pass any examination on the subject of Air Brakes. Endorsed and used by air-brake instructors and examiners on nearly every railroad in the United States. 25th Edition. 350 pages, fully illustrated with folding plates and dia- grams $2.00 AMERICAN COMPOUND LOCOMOTIVES. By FRED. H. COLVIN. The only book on compounds for the engineman or shopman that shows hi a plain, practical way the various features of compound locomotives in use. Shows how they are made, what to do when they break down or balk. Contains sections as follows: A Bit of History. The- ory of Compounding Steam Cylinders. Baldwin Two-Cylinder Compound. Pittsburg Two- Cylinder Compound. Rhode Island Compound. Richmond Compound. Rogers Compound. Schenectady Two-Cylinder Compound. Vauclain Compound. Tandem Compounds. Bald- win Tandem. The Colvin-Wigntman Tandem. Schenectady Tandem. Balanced Loco- motives. Baldwin Balanced Compound. Plans for Balancing. Locating Blows. Break- downs. Reducing Valves. Drifting. Valve Motion. Disconnecting. Power of Compound Locomotives. Practical Notes. Fully illustrated 'and containing ten special "Duotone" inserts on heavy Plate Paper, show- ing different types of Compounds. 142 pages. Price $1.00 APPLICATION OF HIGHLY SUPERHEATED STEAM TO LOCOMOTIVES. By ROBERT GARBE. A practical book. Contains special chapters on Generation of Highly Superheated Steam; Superheated Steam and the Two-Cylinder Simple Engine; Compounding and Superheating; Designs of I Locomotive Superheaters; Constructive Details of Locomotives using Highly Superheated Steam; Experimental and Working Results. Illustrated with folding plates and tables. Price $2.50 COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By WM. M. BARR. This book has been prepared with special reference to the generation of heat by the combus- tion of the common fuels found in the United States, and deals particularly with the condi- tions necessary to the economic and smokeless combustion of bituminous coal in Stationary and Locomotive Steam Boilers. The presentation of this important subject is systematic and progressive. The arrangement of the book is in a series of practical questions to which are appended accurate answers, which describe in language, free from technicalities, the several processes involved in the furnace combustion of American fuels; it clearly states the essential requisites for perfect combustion, and points out the best methods of furnace construction for obtaining the greatest quantity of heat from any given quality of coal. Nearly 350 pages, fully illustrated. Price . $1.00 DIARY OF A ROUND HOUSE FOREMAN. By T. S. REILLY . This is the greatest book of railroad experiences ever published. Containing a fund of infor- mation and suggestions along the line of handling men, organizing, etc., that one cannot afford to miss. 176 pages. Price $1.00 LINK MOTIONS, VALVES AND VALVE SETTING. By FRED H. COLVIN, Associate Editor of "American Machinist." A handy book for the engineer pr machinist that clears up the mysteries of valve setting. Shows the different valve gears in use, how they work, and why. Piston and slide valves of different types are illustrated and explained. A book that every railroad man in the mo- tive power department ought to have. Contains chapters on Locomotive Link Motion, Valve Movements, Setting Slide Valves, Analysis by Diagrams, Modern Practice, Slip of Block, Slide Valves, Piston Valves, Setting Piston Valves, Joy-Allen Valve Gear, Walschaert Valve Gear, Gooch Valve Gear, Alfree-Hubbell Valve Gear, etc., etc. Fully illustrated. Price 50 cents 17 CATALOGUE OF GOOD, PRACTICAL BOOKS LOCOMOTIVE BOILER CONSTRUCTION. By FRANK A. KLEINHANS. The construction of boilers in general is treated, and following this, the locomotive boiler is taken up in the order in which its various parts go through the shop. Shows all types of boilers used; gives details of construction; practical facts, such as life of riveting, punches and dies; work done per day, allowance for bending and flanging sheets, and other data. Locomotive boilers present more difficulty in laying out and building than any other type, and for this reason the author uses them as examples. Anyone who can handle them can tackle anything. Contains chapters on Laying Out Work; Flanging and Forging; Punching; Shearing; Plate Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; Boiler Details; Smoke Box Details; Assembling and Calking; Boiler Shop Machinery, etc., etc. There isn't a man who has anything to do with boiler work, either new or repair work, who doesn't need this book. The manufacturer, superintendent, foreman, and boiler worker all need it. No matter what the type of boiler, you'll find a mint of information that you wouldn't be without. Over 400 pages, five large folding plates. Price $3.00 LOCOMOTIVE BREAKDOWNS AND THEIR REMEDIES. By GEO. L. FOWLEK. Revised by WM. W. WOOD, Air-Brake Instructor. Just issued. Revised pocket edition. It is out of the question to try and tell you about every subject that is covered in this pocket edition of Locomotive Breakdowns. Just imagine all the common troubles that an engineer may expect to happen some time, and then add all of the unexpected ones, troubles that could occur, but that you had never thought about, and you will find that they are all treated with the very best methods of repair. Walschaert Locomotive Valve Gear Troubles, Electric Headlight Troubles, as well as Questions and Answers on the Air Brake are all included. 294 pages. 7th Revised Edition. Fully illustrated $1.00 LOCOMOTIVE CATECHISM. By ROBERT GRIMSHAW. The revised edition of "Locomotive Catechism," by Robert Grimshaw, is a New Book from Cover to Cover. It contains twice as many pages and double the number of illustrations of previous editions. Includes the greatest amount of practical information ever published on the construction and management of modern locomotives. Specially Prepared Chapters on the Walschaert Locomotive Valve Gear, the Air Brake Equipment and the Electric Head Light are given. It commends itself at once to every Engineer and Fireman, and to all who are going in for examination or promotion. In plain language, with full complete answers, not only all the questions asked by the examining engineer are given, but those which the young and less experienced would ask the veteran, and which old hands ask as "stickers." It is a veritable Encyclopedia of the Locomotive, is entirely free from mathematics, easily understood and thoroughly up-to-date. Contains over 4,000 Examination Questions with their Answers. 825 pages, 437 illustrations and three folding plates. 28th Revised Edition. . . $8.50 PRACTICAL INSTRUCTOR AND REFERENCE BOOK FOR LOCOMOTIVE FIREMEN AND ENGINEERS. By CHAS. F. LOCKHART. An entirely new book on the Locomotive. It appeals to every railroad man, as it tells him how things are done and the right way to do them. Written by a man who has had years of practical experience in locomotive shops and on the road firing and running. The infor- mation given in this book cannot be found in any other similar treatise. Eight hundred and fifty-one questions with their answers are included, which will prove specially helpful to those preparing for examination. Practical information on: The Construction and Opera- tion of Locomotives. Breakdowns and their Remedies; Air Brakes and Valve Gears. Rules and Signals are handled in a thorough manner. As a book of reference it cannot be excelled. The book is divided into six parts, as follows: 1. The Fireman's Duties. 2. General description of the Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 5. Extracts from Standard Rules. 6. Questions for examination. The 851 questions have been carefully selected and arranged. These cover the examinations required by the different railroads. 368 pages. 88 illustrations. Price $1.50 PREVENTION OF RAILROAD ACCIDENTS, OR SAFETY IN RAILROADING. By GEORGE BRADSHAW. This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not theories, and showing the men in the ranks, from every-day experience, how accidents occur and how they may be avoided. The book is illustrated with seventy original photographs and draw- ings showing the safe and unsafe methods of work. No visionary schemes, no ideal pictures Just plain facts and Practical Suggestions are given. Every railroad employee who reads the 18 CATALOGUE OF GOOD. PRACTICAL BOOKS book is a better and safer man to have in railroad service. It gives just the information which will be the means of preventing many injuries and deaths. All railroad employees should procure a copy, read it, and do your part in preventing accidents. 169 pages. Pocket Size. Fully illustrated. Price 50 cents TRAIN RULE EXAMINATIONS MADE EASY. By G. E. COLLINGWOOD. This is the only practical work on train-rules in print. Every detail is covered, and puzzling points are explained in simple, comprehensive language, making it a practical treatise for the Train Dispatcher, Engineman, Trainman, and all others who ha Tr e to do with the move- ments of trains. Contains complete and reliable information of the Standard Code of Train Rules for single track. Shows Signals in Colors, as used on the different roads. Explains fully the practical application of train orders, giving a clear and definite understanding of all orders which may be used. The meaning and necessity for certain rules are explained in such a manner that the student may know beyond a doubt the rights conferred under any orders he may receive or the action required by certain rules. As nearly all roads require trainmen to pass regular examinations, a complete set of examina- tion questions, with their answers, are included. These will enable the student to pass tke required examinations with credit to himself and the road for which he works 256 pages Fully illustrated with Train Signals in colors. Price $1.26 TRAIN RULES AND DESPATCHING. By H. A. DALBY. Every railroad man, no matter what department he's in, needs a copy of this book. It givefc, the standard rules for both single and double track, shows all the signals, with colors wher- ever necessary, and has a list of towns where time changes, with a map showing the whole country. The rules are explained wherever there is any doubt about their meaning or where they are modified by different railroads. It's the only practical book on train rules in print Over 220 pages. Leather cover. Price . . $1.50 THE WALSCHAERT AND OTHER MODERN RADIAL VALVE GEARS FOR LOCOMOTIVES. By WM. W. WOOD. If you would thoroughly understand the Walschaert Valve Gear you should possess a copy of this book, as the author takes the plainest form of a steam engine a stationary engine in the rough, that will only turn its crank in one direction and from it builds up with the reader's help a modern locomotive equipped with the Walschaert Valve Gear, complete. The points discussed are clearly illustrated : two large folding plates that show the positions of the valves of both inside or outside admission type, as well as the links and other parts of the gear when the crank is at nine different points in its revolution, are especially valuable in making the movement clear. These employ sliding cardboard models which are contained in a pocket in the cover. The book is divided into five general divisions, as follows: I. Analysis of the gear. II. De- signing and erecting the gear. III. Advantages of the gear. IV. Questions and answers relating to the Walschaert Valve Gear. V. Setting valves with the Walschaert Valve Gear; the three primary types of locomotive valve motion ; modern radial valve gears other than the Walschaert; the Hobart All-free valve and valve gear, with questions and answers on breakdowns; the Baker- Pilliod valve gear; the Improved Baker- Pilliod Valve Gear, with questions and answers on breakdowns. The questions with full answers given will be especially valuable to firemen and engineers in preparing for an examination for promotion. 245 pages. Third Revised Edition. T 'rice $1 . 50 WESTINGHOUSE E T AIR-BRAKE INSTRUCTION POCKET BOOK. By WM. W. WOOD, Air-Brake Instructor. Here is a book for the railroad man, and the man who aims to be one. It is without doubt the only complete work published on the Westinghouse E-T Locomotive Brake Equipment. Written by an Air Brake Instructor who knows just what is needed. It covers the subject thoroughly. Everything about the New Westinghouse Engine and Tender Brake Equip- ment, including the Standard No. 5 and the Perfected No. 6 Style of brake, is treated in de- tail. Written in plain English and profusely illustrated with Colored Plates, which enable one to trace the flow of pressures throughout the entire equipment. The best book ever published on the Air Brake. Equally good for the beginner and the advanced engineer Will pass any one through any examination. It informs and enlightens you on every point. Indispensable to every engineman and trainman. Contains examination questions and answers on the E-T equipment. Covering what the E-T Brake is. How it should be operated. What to do when defective. Not a question can be asked of the engineman up for promotion on either the No. 5 or the No. 6 E-T equipment that is not asked and answered in the book. If you want to thoroughly understand the E-T equipment get a copy of this book. It covers every detail. Makes Air Brake troubles and examinations easy. Price $1.50 CATALOGUE OF GOOD, PRACTICAL BOOKS MACHINE SHOP PEACTICE AMERICAN TOOL MAKING AND INTERCHANGEABLE MANUFACTURING. By J. V. WOODWORTH. A "shoppy" book, containingnotheorizing.no problematical or experimental devices, there are no badly proportioned and impossible diagrams, no catalogue cuts, but a valuable collec- tion of drawings and descriptions of devices, the rich fruits of the author's own experience. In its 500-odd pages the one subject only, Tool Making, and whatever relates thereto, is dealt with. The work stands without a rival. It is a complete practical treatise on the art of American Tool Making and system of interchangeable manufacturing as carried on to-day in the United States. In it are described and illustrated all of the different types and classes of small tools, fixtures, devices, and special appliances which are in general use' in all machine manufacturing and metal working establishments where economy, capacity, and interchangeability in the production of machined metal parts are imperative. The science of jig making is exhaustively discussed, and particular attention is paid to drill jigs, boring, profiling and milling fixtures and other devices in which the parts to be machined are located and fastened within the contrivances. All of the tools, fixtures, and devices illustrated and described have been or are used for the actual production of work, such as parts of drill presses, lathes, patented machinery, typewriters, electrical apparatus, mechan- ical appliances, brass goods, composition parts, mould products, sheet metal articles, drop forgings, jewelry, watches, medals, coins, etc. 531 pages. Price $4.00 HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED TRADES. Edited by JOSEPH G. HORNER, A.M.I., M.E. This set of five volumes contains about 2,500 pages with thousands of illustrations, including diagrammatic and sectional drawings with full explanatory details. This work covers the entire practice of Civil and Mechanical Engineering. The best known expert in all branches of engineering have contributed to these volumes. The Cyclopedia is admirably well adapted to the needs of the beginner and the self-taught practical man, as well as the mechanical en- gineer, designer, draftsman, shop superintendent, foreman, and machinist. The work will be found a means of advancement to any progressive man. It is encyclopedic in scope, thorough and practical in its treatment of technical subjects, simple and clear in its descriptive matter, and without unnecessary technicalities or formulae. The articles are as brief as may be and yet give a reasonably clear and explicit statement of the subject, and are written by men who have had ample practical experience in the matters of which they write. It tells you all you want to know about engineering and tells it so simply, so clearly, so concisely, that one cannot help but understand. As a work of reference it is without a peer. $6.00 per volume. For complete set of five volumes, price $25.00 MACHINE SHOP ARITHMETIC. By COLVIN-CHENEY. This is an arithmetic of the things you have to do with daily. It tells you plainly about: how to find areas of figures; how to find surface or volume of balls or spheres; handy ways for calculating; about compound gearing; cutting screw threads on any lathe; drilling for taps; speeds of drills, taps, emery wheels, grindstones, milling cutters, etc.; all about the Metric system with conversion tables; properties of metals; strength of bolts and nuts; decimal equivalent of an inch. All sorts of machine shop figuring and 1,001 other things, any one of v/hich ought to be worth more than the price of this book to you, and it saves you the trouble of bothering the boss. 6th Edition. 131 pages. Price 50 cents MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND MANAGEMENT. By OSCAR E. PERRIGO. The only work published that describes the Modern Machine Shop or Manufacturing Plant from the time the grass is growing on the site intended for it until the finished product is shipped. Just the book needed by those contemplating the erection of modern shop buildings, the re- building and reorganization of old ones, or the introduction of Modern Shop Methods, time and cost systems It is a book written and illustrated by a practical shop man for practical shop men who are too busy to read theories and want facts. It is the most complete all-around book of its kind ever published. 400 large quarto pages. 225 original and specially-made illustrations. Price $5.00 MECHANICAL APPLIANCES, MECHANICAL MOVEMENTS AND NOVELTIES OF CONSTRUCTION. By GARDNER D. Hiscox. This is a supplementary volume to the one jpon mechanical mpvements. Unlike the first volume which is more elementary in character, this volume contains illustrations and descrip- tions of many combinations of motions and of mechanical devices and appliances found in different lines of machinery. Each device being shown bv a line drawing with a description 20 CATALOGUE OF GOOD, PRACTICAL BOOKS showing its working parts and the method of operation. From the multitude of devices de- scribed, and illustrated, might be mentioned, in passing, such items as conveyors and elevators, Prony brakes, thermometers, various types of boilers, solar engines, oil-fue: burners, condensers, evaporators, Corliss and other valve gears, governors, gas engines, water motors of various descriptions, air ships, motors and dynamos, automobile and motor bicycles, railway block signals, car couplers, link and gear motions, ball bearings, breech block mechanism for heavy guns, and a large accumulation of others of equal importance. 1,000 specially made engrav- ings. 396 octavo pages. Price $2.50 MECHANICAL MOVEMENTS, POWERS, AND DEVICES. By GARDNER D. Hiscox. This is a collection of 1,890 engravings of different mechanical motions and appliances, accom- panied by appropriate text, making it a book of great value to the inventor, the draftsman, and to all readers with mechanical tastes. The book is divided into eighteen sections or chapters in which the subject matter is classified under the following heads: Mechanical Powers; Transmission of Power; Measurement of Power, Steam Power; Air Power Appliances; Electric Power and Construction, Navigation and Roads; Gearing; Motion and Deyices; Controlling Motion; Horological; Mining; Mill and Factory Appliances; Construction and Devices; Draft ing Devices: Miscellaneous Devices, etc. 12th edition, 400 octavo pages. Price $2.50 MACHINE SHOP TOOLS AND SHOP PRACTICE. By W. H. VANDERVOORT. A work of 555 pages and 673 illustrations, describing in every detail the construction, operation, and manipulation of both hand and machine 10913. Includes chapters on filing, fitting, and scraping surfaces; on drills, reamers, taps, and dies; the lathe and its tools; planers, shapers, and their tools: milling machines and cutters ; gear cutters and gear. cutting; drilling machines and drill work; grinding machines and their work; hardening and tempering ; gearing, belting and transmission machinery: useful data and tables. 6th edition. Price . . . $3.00 THE MODERN MACHINIST. By JOHN T. USHER. This is a book showing, by plain description and by profuse engravings, made expressly for the work, all that is best, most advanced, and of the highest efficiency in modern machine shop practice, tools, and implements, showing the way by which and through which, as Mr. Maxim says, "American machinists have become and are the finest mechanics in the world." Indicating as it does, in every line, the familiarity of the author with every detail of daily experience in the slK>p, it cannot fail to be of service to any man .practically connected with the shaping or finishing of metals. There is nothing experimental or visionary about the book, all devices being in actual use and giving good results. It might be called a compendium of shop methods, showing a vari- ety of special tools and appliances which will give new ideas to many mechanics, from the superintendent down to tne man at the bench. It will be found a valuable addition to any machinist's library, and should be consulted whenever a new or difficult job is to be done, whether it is boring, milling, turning, or planing, as they are all treated in a practical manner. Fifth Edition. 320 pages. 250 illustrations. Price ... $2.50 MODERN MILLING MACHINES: THEIR DESIGN, CONSTRUCTION AND OPERA- TION. By JOSEPH G. HORNER. This book describes and illustrates the Milling Machine and its work in such a plain, clear, and forceful manner, and illustrates the subject so clearly and completely, that the up-to-date machinist, student, or mechanical engineer cannot afford to do without the valuable infor- mation which it contains. It describes not only the early machines of this class, but notes their gradual development into the splendid machines of the present day, giving the design and construction of the various types, forms, and special features produced by prominent manufacturers, American and foreign. Milling cutters in all their development and modernized forms are illustrated and described, and the operations they are capable of producing upon different classes of work are carefully described in detail, and the speeds and feeds necessary are discussed, and valuable and useful data given for determining these usually perplexing problems. The book is the most compre- hensive work published on the subject. 304 pages. 300 illustrations. Price . . $4.00 " SHOP KINKS." By ROBERT GRIMSHAW. A bo9k of 400 pages and 222 illustrations, being entirely different frorrA any other book on machine shop practice. Departing from conventional style, the author avoids universal or common shop usage and limits his work to showing special ways of doing things better, more cheaply and more rapidly than usual. As a result the advanced methods of representative establishments of the world are placed at the disposal of the reader. This book shows the proprietor where large savings are possible, and now products may be improved. To the employee it holds out suggestions that, properly applied, will hasten his advancement. No shop can afford to be without it. It bristles with valuable wrinkles and helpful suggestions. It will benefit all, from apprentice to proprietor. Every machinist, at any age. should study its pages. Fifth Edition. Price $2.50 21 CATALOGUE OF GOOD, PRACTICAL BOOKS THREADS AND THREAD CUTTING. By COLVIN and STABEL. This clears up many of the mysteries of thread-cutting, such as double and triple threads, internal threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several tables. 3rd Edition. Price .35 cents TOOLS FOR MACHINISTS AND WOOD WORKERS, INCLUDING INSTRUMENTS OF MEASUREMENT. By JOSEPH G. HORNER. The principles upon which cutting tools for wood, metal, and other substances are made are identical, whether used by the machinist, the carpenter, or by any other skilled mechanic in their daily work, and the object of this book is to give a correct and practical description of these tools as they are commonly designed, constructed, and used. 340 pages, fully illustrated. Price $3.50 MANUAL TRAINING ECONOMICS OF MANUAL TRAINING. By Louis ROUILLION. The only book published that gives just the information needed by all interested in Manual Training, regarding Buildings, Equipment, and Supplies. Shows exactly what is needed for all grades of the work from the Kindergarten to the High and Normal School. Gives item- ized lists of everything used in Manual Training Work and tells just what it ought to cost. Also shows where to buy supplies, etc. Contains 174 pages, and is fully illustrated. 2nd Edition. Price $1.50 MARINE ENGINEERING MARINE ENGINES AND BOILERS, THEIR DESIGN AND CONSTRUCTION. By DR. G. BAUER, LESLIE S. ROBERTSON, and S. BRYAN DONKIN. In the words of Dr. Bauer, the present work owes its origin to an oft felt want of a Condensed Treatise, embodying the Theoretical and Practical Rules used in Designing Marine Engines and Boilers. The need for such a work has been felt by most engineers engaged in the con- struction and working of Marine Engines, not only by the younger men, but also by those of greater experience. The fact that the original German work was written by the chief engineer of the famous Vulcan Works, Stettin, is in itself a guarantee that this book is in all respects thoroughly up-to-date, and that it embodies all the information which is necessary for the design and construction of the highest types of marine engines and boilers. It may be said, that the motive power which Dr. Bauer has placed in the fast German liners that have been turned out of late years from the Stettin Works, represent the very best practice in marine engineering of the present day. This work is clearly written, thoroughly systematic, theoretically sound; while the character of its plans, drawings, tables, and statistics is without reproach. The illustrations are care ful reproductions from actual working drawings, with some well-executed photographic views of completed engines and boilers. 744 pages. 550 illustrations and numerous tables. $9.00 net MODERN SUBMARINE CHART. A cross-section view, showing clearly and distinctly all the interior of a Submarine of the latest type. You get more information from this chart, about the construction and operation of a Submarine, than in any other way. No Details omitted everything is accurate and to scale. It is absolutely correct in every detail, having been approved by Naval Engineers. All the machinery and devices fitted in a modern Submarine Boat are shown and to make the engraving more readily understood all the features are shown in operative form with Officers and Men in the act of performing the duties assigned to them in service conditions. This CHART IS REALLY AN ENCYCLOPEDIA OP A SUBMARINE. It is educational and worth many times its cost. Mailed in a Tube for .25 cents MINING ORE DEPOSITS, WITH A CHAPTER ON HINTS TO PROSPECTORS. By J. P. JOHNSON This book gives a condensed account of the ore-deposits at present known in South Africa. It is also intended as a guide to the prospector. Only an elementary knowledge of geology and some mining experience are necessary in order to understand this work. With these qualifications, it will materially assist one in his search for metalliferous nuneral occurrences 22 CATALOGUE OF GOOD, PRACTICAL BOOKS and, so far as simple ores are concerned, should enable one to form some idea of the possi- bilities of any he may find. Among the chapters given are: Titaniferous and Chromiferous Irpn Oxides Nickel Cop- per Cobalt Tin Molybdenum Tungsten Lead Mercury Antimony Iron Hints to Prospectors $2.00 PHYSICS AND CHEMISTRY OF MINING. By T. H. BYROM. A practical work for the use of all preparing for examinations in mining or qualifying for colliery managers' certificates. The aim of the author in this excellent book is to place clearly before the reader useful and authoritative data which will render him valuable assistance in his studies. The only work of its kind published. The information incprporated in it will prove of the greatest practical utility to students, mining engineers, colliery managers, and all others who are specially interested in the present-day treatment of mining problems. Among its contents are chapters on: The Atmosphere; Laws Relating to the Behavior of Gases; The Diffusion of Gases; Composition of the Atmosphere: Sundry Constituents of the Atmosphere; Water; Carbon; Fire-Damp; Combustion; Coal Dust and Its Action; Ex- plosives; Composition of Various Coals and Fuels; Methods of Analysis of Coal; Strata Ad- joining the Coal Measures; Magnetism and Electricity; Appendix; Useful Tables, etc ; Miscellaneous Questions. 160 pages. Illustrated $2.00 PRACTICAL COAL MINING. By T. H. COCKIN. An important work, containing 428 pages and 213 illustrations, complete with practical de- tails, which will intuitively impart to the reader, not only a general knowledge of the princi- ples of coal mining, but also considerable insight into allied subjects. This treatise is posi- tively up to date in every instance, and should be in the hands of every colliery engineer, geologist, mine operator, superintendent, foreman, and all others who are interested in or connected with the industry. 2nd Edition $2.50 PATTERN MAKING PRACTICAL PATTERN MAKING. By F. W. BARROWS. This is a very complete and entirely practical treatise on the subject of pattern making, illus- trating pattern work in wood and metal. From its pages you are taught just what you should know about pattern making. It contains a detailed description of the materials used by pattern makers, also the tools, both those for hand use, and the more interesting machine tools ; having complete chapters on the band saw, The Buzz Saw, and the Lathe. Individual patterns of many different kinds are fully illustrated and described, and the mounting of metal patterns on plates for molding machines is included. Rules, Formulas and Tables are included, containing simple and original methods for finding the weight of castings, both from the pattern itself and from the drawings. This section contains some new and practical formulas, which will be found very useful in estimating weights, with the accuracy required for quotations to prospective customers. All of these rules are simple, and can be put to practical use by the ordinary, every-day man, and they have been proved by years of actual use. Plain rules for keeping down the cost of patterns, with a complete system for checking the cost of and marking the patterns, and a card record showing what the pattern is, material used, where located in safe, with its cost and date of production, is included. The book closes with an original and practical method for the inventory and valuation of patterns. Con- taining 326 pages and 150 detailed illustrations. Price $2.00 PERFUMERY HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- CESSES. Edited by G. D. Hiscox. The most valuable Techno-chemical Receipt Book published. Contains over 10,000 practical receipts, many of which will prove of special value to the perfumer, a mine of information, up- to-date in every respect. Price, Cloth, $3.00; half morocco $4.0O PERFUMES AND THEIR PREPARATION. By G. W. ASKINSON, Perfumer. A comprehensive treatise, hi which there has been nothing omitted that could be of value to the Perfumer. Complete directions for making handkerchief perfumes, smelling-salts, sachets, fumigating pastilles: preparations for the care of the skin, the mouth, the hair, cos- metics, hair dyes and other toilet articles are given, also a detailed description of aromatic suostances: their nature, tests of purity, and wholesale manufacture. A book of general, as well as professional interest, meeting the wants not only of the druggist and perfume man- ufacturer, but also of the general public. Third edition. 312 pages. Illustrated. . $3.00 2 3 CATALOGUE OF GOOD, PRACTICAL BOOKS PLUMBING MECHANICAL DRAWING FOR PLUMBERS. By R. M. STARBUCK. A concise, comprehensive and practical treatise on the subject of mechanical drawing in its various modern applications to the work of all who are in any way connected with *he plumbing trade. Nothing will so help the plumber in estimating and in explaining work to customers and workmen as a knowledge of drawing, and to the workman it is of inestimable value if he is to rise above his position to positions of greater responsibility. Among the chapters contained are: 1. Value to plumber of knowledge of drawing; tools required and their use; common views needed in mechanical drawing. 2. Perspective versus mechan- ical drawing in showing plumbing construction. 3. Correct and incorrect methods in plumbing drawing; plan and elevation explained. 3. Floor and cellar plans and elevation; scale drawings; use of triangles. 5. Use of triangles; drawing of fittings, traps, etc. 6. Drawing plumbing elevations and fittings. 7. Instructions in drawing plumbing elevations. 8. The drawing of plumbing fixtures ; scale drawings. 9. Drawing of fixtures and fittings. 10. Inking of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sec- tional drawings; drawing of threads. 14. Plumbing elevations from architect's plan. 15. Elevations of separate parts of the plumbing system. 16. Elevations from architect's plans. 17. Drawing of detail plumbing connections. 18. Architect's plans and plumbing elevations of residence. 19. Plumbing elevations of residence (continued) ; plumbing plans for cottage. 20. Plumbing elevations; roof connections. 21. Plans and plumbing eleva- tions for six-flat building. 22. Drawing of various parts of the plumbing system; use of scales. 23. Use of architect's scales. 24. Special features in the illustrations of country plumbing. 25. Drawing of wrought iron piping, valves, radiators, coils, etc. 26. Drawing of piping to illustrate heating systems. 150 illustrations. Price $1.50 MODERN PLUMBING ILLUSTRATED. By R. M. STARBUCK. This book represents the highest standard of plumbing work. It has been adopted and used as a reference book by the United States Government, in its sanitary work in Cuba, Porto Rico, and the Philippines, and by the principal Boards of Health of the United States and Canada. It gives connections, sizes and working data for all fixtures and groups of fixtures. It is helpful to the master plumber in demonstrating to his customers and in figuring work. It fives the mechanic and student quick and easy access to the best modern plumbing practice, uggestions for estimating plumbing construction are contained in its pages. This book represents, in a word, the latest and best up-to-date practice, and should be in the hands of every architect, sanitary engineer and plumber who wishes to keep himself up to the minute on this important feature of construction. Contains following chapters, each illustrated with a full-page plate: Kitchen sink, laundry tubs, vegetable wash sink; lavatories, pantry sinks, contents of marble slabs; bath tub, foot and sitz bath, shower bath; water closets, venting of water closets; low-down water closets, water closets operated by flush valves, water closet range; slop sink, urinals, the bidet; hotel and restaurant sink, grease trap; refrigerators, safe wastes, laundry waste; lines of refrigerators, bar sinks, soda foun- tain sinks; horse stall, frost-proof water closets; connections for S traps, venting; con- nections for drum traps; soil pipe connections; supporting of soil pipe; main trap and fresh air inlet; floor drains and cellar drains, subsoil drainage; water closets and floor connections; local venting; connections for bath rooms ; connections for bath rooms, con- tinued; connections for bath rooms, continued; connections for bath rooms, continued; examples of poor practice; roughing-work ready for test; testing of plumbing system; method of continuous venting ; continuous venting for two-floor work ; continuous venting for two lines of fixtures on three or more floors ; continuous venting of water closets ; plumb- ing for cottage house; construction for cellar piping; plumbing for residence, use of special fittings; plumbing for two-flat house; plumbing for apartment building; plumbing for double apartment building; plumbing for office building; plumbing for public toilet rooms; plumbing for public toilet rooms, continued; plumbing for bath establishment; plumbing for engine house, factory plumbing ; automatic flushing for schools, factories, etc. ; use of flushing valves; urinals for public toilet rooms; the Durham system, the destruction of pipes by electrolysis; construction of work without use of lead; Automatic sewage lift, automatic sump tank; country plumbing; construction of cesspools; septic tank and auto- matic sewage siphon; country plumbing; water supply for country house; thawing of water mains and service by electricity; double boilers; hot water supply of large build- ings; automatic control of hot water tank; suggestions for estimating plumbing construc- tion. 400 octavo pages, fully illustrated by 55 full-page engravings. Price . $4.00 STANDARD PRACTICAL PLUMBING. By R. M. STARBUCK. A complete practical treatise of 450 pages covering the subject of Modern Plumbing in all its branches, a large amount of space being devoted to a very complete and practical treatment of the subject of Hot Water Supply and Circulation and Range Boiler Work. Its thirty chapters include about every phase of the subject one can think of, making it 24 CATALOGUE OF GOOD, PRACTICAL BOOKS an indispensable work to the master plumber, the journeyman plumber, and the apprentice plumber, containing chapters on: the plumber's tools; wiping solder, composition and use; joint wiping; lead worK; traps; siphonage of traps; venting; continuous venting; house sewer and sewer connections; house drain; soil piping, roughing; main trap and fresh air inlet; floor, yard, cellar drains, rain leaders, etc. ; fixture wastes : water closets ; ventilation; improved plumbing connections; residence plumbing; plumbing for hotels, schools, fac- tories, stables, etc.; modern country plumbing; filtration of sewage and water supply; hot and cold supply; range boilers; circulation; circulating pipes; range boiler problems; hot water for large buildings; water lift and its use; multiple connections for hot water boilers; heating of radiation by supply system; theory for the plumber; drawing for the plumber. Fully illustrated by 347 engravings. Price $3.00 RECEIPT BOOK HENLEY'S TWENTIETH CENTURY BOOK OF RECEIPTS, FORMULAS AND PRO- CESSES. Edited by GARDNER D. Hiscox. The most valuable Techno-chemical Receipt Book published, including over 10,000 selected scientific, chemical, technological, and practical receipts and processes. This is the most complete Book of Receipts ever published, giving thousands of receipts for the manufacturer of valuable articles for everyday use. Hints, Helps, Practical Ideas, and Secret Processes are revealed within its pages. It covers every branch of the useful arts and tells thousands of ways of making money and is just the book everyone should have at his command. Modern in its treatment of every subject that properly falls within its scope, the book may truthfully be said to present the very latest formulas to be found in the arts and industries and to retain those processes which long experience has proven worthy of a permanent record To present here even a limited number o! the subjects which find a place hi this valuable work would be difficult. Suffice to say that in its pages will be found matter of intense in- terest and immeasurable practical value to the scientific amateur and to him who wishes to obtain a knowledge of the many processes used in the arts, trades and manufactures, a knowledge which will render his pursuits moro instructive and remunerative. Serving as a reference book to the small and large manufacturer and suppplying intelligent seekers with the information necessary to conduct a process, the work will be found of inestimable worth to the Metallurgist, the Photographer, the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, and Mucilages, the Compounder of Alloys, the Cook, the Physician, the Druggist, the Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, the Potter, the Tanner, the Confectioner, the Chiropodist, the Manicure, the Manufacturer of Chemical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, the Engraver, the Provisioner. the Glass Corker, the Goldbeater, the Watchmaker, the Jew- eler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, the Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary Surgeon, and the Technologist in general. A mine of information, and up-to-date in every respect. A book which will prove of value to EVERYONE, as it covers every branch of the Useful Arts. 800 pages. Price $3.00 WHAT IS SAID OF THIS BOOK: " Your Twentieth Century Book of Receipts, Formulas and Processes duly received. I am glad to have a copy of it, and if I could not replace it money couldn't buy it. It is the best thing of the sort I ever saw." (Signed) M. E. TRUX, Sparta, Wis. ' There are few persons who would not be able to find in the book some single formula that would repay several times the cost of the book." Merchant's Record and Show Window. RUBBER RUBBER HAND STAMPS AND THE MANIPULATION OF INDIA RUBBER. By T. O'CoNOR SLOANE. This book gives full details on all points, treating in a concise and simple manner the elements of nearly everything it is necessary to understand for a commencement in any branch of the India Rubber Manufacture. The making of all kinds of Rubber Hand Stamps, Small Articles of India Rubber, U. S. Government Composition, Dating Hand Stamps, the Manipulation of Sheet Rubber, Toy Balloons. India Rubber Solutions, Cements, Blackings, Renovating 2 S CATALOGUE OF GOOD, PRACTICAL BOOKS Varnish, and Treatment for India Rubber Shoes, etc.; the Hektograph Stamp Inks and .Miscellaneous Notes, with a Short Account 9f the Discovery, Collection, and Manufacture of India Rubber are set forth in a manner designed to be readily understood, the explanations being plain and simple. Including a chapter on Rubber Tire Making and Vulcanizing- also a chapter on the uses of rubber in Surgery and Dentistry. Third revised and enlarged edition. 175 pages. Illustrated $1.0O SAWS SAW FILINGS AND MANAGEMENT OF SAWS. By ROBERT GRIMSHAW. A practical hand book on filing, gumming, swaging, hammering, and the brazing of band saws, the speed, work, and power to run circular saws, etc. A handy book for those who have charge of saws, or for those mechanics who do their own filing, as it deals with the proper shap. j and pitches of saw teeth of all kinds and gives many useful hints and rules for gumming, setting, and filing, and is a practical aid to those who use saws for any purpose. New edition, revised and enlarged. Illustrated. Price $1.00 STEAM ENGINEERING AMERICAN STATIONARY ENGINEERING. By W. E. CRANE. This book begins at the boiler room and takes in the whole power plant. A plain talk on eyery-day work about engines, boilers, and their accessories. It is not intended to be scien- tific or mathematical. All formulas are in simple form so that any one understanding plain arithmetic can readily understand any of them. The author has made this the most prac- tical book in print; has given the results of his years of experience, and has included about ',11 that has to do with an engine room or a power plant. You are not left to guess at a single joint. You are shown clearly what to expect under the various conditions ; how to secure the best results; ways of preventing "shut downs" and repairs; in short, all that goes to make up the requirements of a good engineer, capable of taking charge of a plant. It's plain enough for practical men and yet of value to those high in the profession. V partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps; nspection and repair ; chimneys, sizes and cost ; piping ; mason work ; foundations ; testing ,-ement; pile driving; engines, slow and high speed; valves; valve setting ; Corliss engines, jetting valves, single and double eccentric; air pumps and condensers; different types of condensers; water needed; lining up; pounds; pins not square in crosshead or crank; engineers' tools; pistons and piston rings; bearing metal ; hardened copper ; drip pipes from cylinder jackets; belts, how made, care of; oils; greases; testing lubricants; rules and tables, including steam tables; areas of segments; squares and square root; cubes and cube root; areas and circumferences of circles. Notes on: Brick work; explosions; pumps; pump valves; heaters, economizers; safety valves; lap. lead, and clearance. Has a complete examination for a license, etc., etc. Second edition. 285 pages. Illustrated. Price . $2.00 EMINENT ENGINEERS. By DWIGHT GODDARD. Everyone who appreciates the effect of such great inventions as the Steam Engine, Steamboat, Locomotive, Sewing Machine, Steel Working, and other fundamental discoveries, is interested in knowing a little about the men who made them and their achievements. Mr. Goddard has selected thirty-two of the world's engineers who have contributed most largely to the advancement of our civilization by mechanical means, giving only such facts as are of general interest and in a way which appeals to all, whether mechanics or not. 280 pages. 35 illustrations. Price $1.50 ENGINE RUNNER'S CATECHISM. By ROBERT GRIMSHAW. A practical treatise for the stationary engineer, telling how to erect, adjust and run the prin- cipal steam engines in use in the United States. Describing the principal features of various special and well-known makes of engines: Temper Cut-off, Shipping and Receiving Founda- tions, Erecting and Starting, Valve Setting, Care and Use, Emergencies, Erecting and Ad- justing Special Engines. Ths questions asked throughout the catechism are plain and to the point, and the answers a "a given in such simple language as to be readily understood by anyone. All the instructions clven are complete and up-to-date; and they are written in a popular style, without any technicalities or mathematical formula. The work is of a handy size for the pocket, clearly and well printed, nicely bound, and profusely illustrated. To young engineers this catechism 26 CATALOGUE OF GOOD, PRACTICAL BOOKS will be of great value ; especially to those whu may be preparing to go forward to be examined for certificates of competency; and to engineers generally it will be of no little service, as they will find in this volume more really practical and useful information than is to be found any- where else within a like compass. 387 pages. Seventh edition. Price .... $2.00 ENGINE TESTS AND BOILER EFFICIENCIES. By J. BUCHETTI. This work fully describes and illustrates the method of testing the power of steam engines, turbines and explosive motors. The properties of steam and the evaporative power of fuels. Combustion of fuel and chimney draft; with formulas explained or practically cpmputed 255 pages, 179 illustrations $3.00 HORSEPOWER CHART. Shows the horsepower of any stationary engine without calculation. No matter what the cylinder diameter of stroke; the steam pressure or cut off; the revolutions, or whether con- densing or non-condensing, it's all there. Easy to use, accurate, and saves time and calcu- lations. Especially useful to engineers and designers 50 cents MODERN STEAM ENGINEERING IN THEORY AND PRACTICE. By GARDNER D. Hiscox. This is a complete and practical work issued for Stationary Engineers and firemen dealing with the care and management of boilers, engines, pumps, superheated steam, refrigerating machinery, dynamos, motors, elevators, air compressors, and all other branches with which the modern engineer must be familiar. Nearly 200 questions with their answers on steam and electrical engineering, likely to be asked by the Examining Board, are included. Among the chapters are: Historical; steam and its properties; appliances for the genera- tion of steam; types of boilers; chimney and its work; heat economy of the feed water; steam pumps and their work ; incrustation and its work ; steam above atmospheric pressure ; flow of steam from nozzles; superheated steam and its work; adiabatic expansion of steam; indicator and its work; steam engine proportions; slide valve engines and valve motion; Corliss engine and its valve gear; compound engine and its theory; triple and multiple expansion engine, steam turbine; refrigeration; elevators and their management; cost of power; steam engine troubles; electric power and electric plants. 487 pages. 405 en- gravings. Price $3.00 STEAM ENGINE CATECHISM. By ROBERT GRIMSHAW. This unique volume of 413 pages is not only a catechism on the question and answer princi- ple; but it contains formulas and worked-out answers for all the Steam problems that apper- tain to the operation and management of the Steam Engine. Illustrations of various valves and valve gear with their principles of operation are given. Thirty-four Tables that are indispensable to every engineer and fireman that wishes to be progressive and is ambitious to become master of his calling are within its pages. It is a most valuable instructor in the service of Steam Engineering. Leading engineers have recommended it as a valuable educa- tor for the beginner as well as a reference book for the engineer. It is thoroughly indexed for every detail. Every essential question on the Steam Engine with its answer is contained in this valuable work. Sixteenth edition. Price $2.00 STEAM ENGINEER'S ARITHMETIC. By COLVIN-CHENEY. A practical pocket book for the steam engineer. Shows how to work the problems of the engine room and shows "why." Tells how to figure horse-power of engines and boilers; area of boilers; has tables of areas and circumferences; steam tables; has a dictionary of engineering terms. Puts you on to all all of the little kinks in figuring whatever there is to figure around a power plant. Tells you about the heat unit; absolute zero; adiabatic expansion; duty of engines; factor of safety; and 1,001 other things; and everything is plain and simple not the hardest way to figure, but the easiest. 2nd Edition 50 cents STEAM HEATING AND VENTILATION PRACTICAL STEAM, HOT- WATER HEATING AND VENTILATION. By A. G. KING. This book is the standard and latest work published on the subject and has been prepared for the use of all engaged in the business of steam, hot water heating, and ventilation. It is an original and exhaustive work. Tells how to get heating contracts, how to install heating and ventilating apparatus, the best business methods to be used, with "Tricks of the Trade" for 27 CATALOGUE OF GOOD, PRACTICAL BOOKS shop use. Rules and data for estimating radiation and cost and such tables and information as make it an indispensable work for everyone interested in steam, hot water heating, and venti- lation. It describes all the principal systems of steam, hot water, vacuum, vapor, and vacuum- vapor heating, together with the new accelerated systems of hot water circulation, including chapters on up-to-date methods of ventilation and the fan or blower system of heating and ventilation. Containing chapters on: I. Introduction. II. Heat. III. Evolution of artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. VI. Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating surfaces. IX. Locating of radiating surfaces. X. Estimating radiation. XI. Steam-heating apparatus. XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. Pressure systems of hot- water work. XV. Hot- water appliances. XVI. Greenhouse heating. XVII. Vacuum vapor and vacuum exhaust heating. XVIII. Miscellaneous heating. XIX. Radiator and pipe connections. XX. Ventilation. XXI. Mechanical ventilation and hot-blast heating. XXII. Steam appliances. XXIII. District heating. XXIV. Pipe and boiler covering. XXV. Temperature regulation and heat control. XXVI. Business methods. XXVII. Miscellaneous. XXVIII. Rules, tables and useful information. 367 pages. 300 detailed engravings. Price $3.00 STEAM PIPES STEAM PIPES: THEIR DESIGN AND CONSTRUCTION. By WM. H. BOOTH. The work is well illustrated in regard to pipe joints, expansion offsets, flexible joints, and self-contained sliding joints for taking up the expansion of long pipes. In fact, the chapters on the flow of steam and expansion of pipes are most valuable to all steam fitters and users. The pressure strength of pipes and method of hanging them are well treated and illustrated. Valves and by-passes are fully illustrated and described, as are also flange joints and their proper proportions, exhaust heads and separators. One of the most valuable chapters is that on superheated steam and the saving of steam by insulation with the various kinds of felt- ing and other materials with comparison tables of the loss of heat in thermal units from naked and felted steam pipes. Contains 187 pages. Price $2.00 STEEL AMERICAN STEEL WORKER. By E. R. MARKHAM. This book tells how to select, and how to work, temper, harden, and anneal steel for everything on earth. It doesn't tell how to temper one class of tools and then leave the treatment of another kind of tool to your imagination and judgment, but it gives careful instructions for every detail of every tool, whether it be a tap, a reamer or just a screw-driver. It tells about the tempering of small watch springs, the hardening of cutlery, and the annealing of dies. In fact there isn't a thing that a steel worker would want to know that isn't included. It is the standard book on selecting, hardening, and tempering all grades of steel. Among the chapter headings might be mentioned the following subjects: Introduction; the workman; steel; methods of heating ; heating tool steel ; forging; annealing; hardening baths; baths for hardening; hardening steel; drawing the temper after hardening; examples of hard- ening; pack hardening ; case hardening; spring tempering; making tools of machine steel; special steels; steel for various tools; causes of trouble; high speed steels, etc. 366 pages. Very fully illustrated. 3rd Edition. Price $2.50 HARDENING, TEMPERING, ANNEALING, AND FORGING OF STEEL. By J. V. WOODWORTH. A new work treating in a clear, concise manner all modern processes for the heating, annealing forging, welding, hardening, and tempering of steel, making it a book of great practical value to the metal-working mechanic in general, with special directions for the successful hardening and tempering of all steel tools used in the arts, including milling cutters, taps, thread dies, reamers, both solid and shell, hollow mills, punches and dies, and all kinds of sheet metal working tools, shear blades, saws, fine cutlery, and metal cutting tools of all description, as well as for all implements of steel both large and small. In this work the simplest and most satisfactory hardening and tempering processes are given. The uses to which the leading brands of steel may be adapted are concisely presented, and their treatment for working under different conditions explained, also the special methods for the hardening and tempering of special brands. A chapter d'evoted to the different processes for Case-hardening is also included, and special reference made to the adoption of machinery steel for tools of various kinds. 4th Edition. 288 pages. 201 Illustrations. Price $2.50 28 CATALOGUE OF GOOD, PRACTICAL BOOKS TURBINES MARINE STEAM TURBINES. By DR. G. BAUER and O. LASCHE. Assisted by E. Ludwig and H. Vogel. Translated from the German and edited by M. G. S. Swallow. This work forms a supplementary volume to the book entitled "Marine Engines and Boilers." The authors of this book, Dr. G. Bauer and O. Lasche, may be regarded as the leading authorities on turbine construction. The book is essentially practical and discusses turbines in which the full expansion of steam passes through a number of separate turbines arranged for driving two or more shafts, as in the Parsons system, and turbines in which the complete expansion of steam from inlet to exhaust pressure occurs in a turbine on one shaft, as in the case of the Curtis machines. It will enable a designer to carry out all the ordinary calculations necessary for the con- struction of steam turbines, hence it fills a want which is hardly met by larger and more theoretical works. Numerous tables, curves and diagrams will be found, which explain with remarkable lucidity the reason why turbine blades are designed as they are, the course which steam takes through turbines of various types, the thermodynamics of steam turbine calculation, the influence of vacuum on steam consumption of steam turbines, etc. In a word, the very information which a designer and builder of steam turbines most requires. The book is divided into parts as follows: 1. Introduction. 2. General remarks on the design of a turbine installa- tion. 3. The calculation of steam turbines. 4. Turbine design. 5. Shafting and pro- pellers. 6. Condensing plant. 7. Arrangement of turbines. 8. General remarks on the arrangement of steam turbines in steamers. 9. Turbine-driven auxiliaries. 10. Tables. Large octavo. 214 pages. Fully illustrated and containing 18 tables. Including an entropy chart. Price, net $3.50 WATCH MAKING WATCHMAKER'S HANDBOOK. By CLAUDIUS SAUNIER. This famous work has now reached its seventh edition and there is no work issued that can compare to it for clearness and completeness. It contains 498 pages and is intended as a workshop companion for those engaged in Watch-making and allied Mechanical Arts. Nearly 250 engravings and fourteen plates are included. Price ... .... $3.00 2 9 UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. ENGINEERING LIBRARY MAR 4 195i DEC 2 1 i/ LD 21-100m-9,'48(B399sl6)476 ,<70 TU 302971 Engineering Library i UNIVERSITY OF CALIFORNIA LIBRARY