PRACTICAL ENGINEER AND MECHANICS' GUIDE, CONTAINING A GLANCE AT THE EARLY HISTORY OF STEAM; ITS APPLICATION TO ITS MORE EXTENSIVE USE FOR GENERAL MACHINERY. THE SETTING AND MANAGEMENT OF BOILERS: THE MODERN STEAM ENGINE; HOW IT SHOULD BE MANAGED. THE BEST POSSIBLE CONDITION FOR DUTY. TABLES AND RULES DE- OF THE ENGINE, WITH FOR DEMONSTRATING THE ACTUAL WORKING TIONS. TABLES FOR VARIOUS CALCULATIONS RELATING SECOND EDITION--REVISED AND IMPROVED. PUBLISHED BY THE AUTHOR. LOWELL, MASS.: 18944; Dec. 219. scientific school. 345.36 JUN 20 1317 TRANSFERRED TO MANYAKU COLLEGE LITRARY Entered at Office of Librarian of Congress at Washington, D. C. PREFACE. In offering the second edition of this book to the Public, especially to that class known as Steam Engineers, the author desires to lay before them such facts and general information as he has gained by an experience of many years in the business. In doing this he wishes to help to elevate, and make more competent a large class, which in this age of Steam, has become an important element in the world's advancement, and upon which largely depends the safety of transportation of passengers and freight throughout the world. Also, in the busy hives of industry everywhere, much depends upon the economical production, care, and useful application of Steam. In presenting this book, it is not claimed that the rules, tables and formulas for calculation are entirely new, the author is largely indebted to such works as Haswell, Winslow, Briggs, Bacon and Howard, for which he makes due acknowledgement. But seeing from many years intercourse with the class of men herein named, the great need of a practical treatise on Steam Engineering, presented in such a form as would be readily understood by those directly interested, and especially beneficial to young engineers, he cannot but hope this work will reach the class for whom it is intended, and be found interesting and helpful to them. Slight changes have been made in a few instances, and the page on electric lighting has been rewritten to meet the greatly reduced cost of electric lighting machinery, materials, and supplies. The book as improved, is submitted to the public with thanks by the author for their appreciation of the first edition. = DEFINITIONS OF THE SIGNS USED IN THE FOLLOWING WORK. Equal to. The sign of equality; as 16 oz.=1 lb. + Plus, or More. The sign of addition; as 8+12=20. Minus, or Less. × Multiplied by. The sign of multiplication; as 12×8=96. The sign of subtraction; as 12—8=4. Divided by. The sign of division; as 12÷4=3. Difference between the given numbers or quantities; thus, 128, or 812, shows that the less number is to be subtracted from the greater, and the difference, or remainder, only, is to be used, so, too, height breadth shows that the difference between the height and breadth is to be taken. : ::: Proportion; as 2: 4 :: 3:6; that is, as 2 is to 4, so is 3 to 6. Sign of the square root; prefixed to any number indicates that the square root of that number is to be taken, or employed; as ✅64=8. Sign of the cube root; and indicates that the cube root of the number to which it is prefixed is to be employed, instead of the number itself; 64-4. as To be squared, or the square of; shows that the square of the number to which it is affixed is the quantity to be employed; as 12÷6=24 ; that is, that the square of 12, or 144÷6=24. Indicates that the cube of the number to which it is subjoined is to be used; as 43=64. Decimal point, or separatrix. Vinculum. Signifies that the two or more sums, over which it is drawn, are to be taken together, or collectively, as forming one sum, thus, 4+6×4=40; whereas. without the vinculum, 4+6×4=28; also 12—2×3+4=2; and √52—32=4. So, also, ✅ (52—32)=4. % Sign of per cent. Signifies so much per cent; as $1.00 at 6%, or 6% of $1.00-6 cents. "Signifies degrees, minutes and seconds. A GLANCE AT THE HISTORY OF STEAM. Steam has been used as a motive power for upwards of two hundred years, but not until James Watt, near the latter part of the last century, made a successful application of it for driving machinery and pumping water, and later Robert Fulton and Oliver Evans applied it to the steamboat, and George Stephenson to the locomotive, was it considered a success. Although the early efforts of Watt were very crude, yet his principles of the steam engine are the base of the advanced successful steam engine of to-day. The same ideas of expansion, condensation and regulation by automatic cut-off, occupied his thoughts (although he did not make a success of the last), and were the controlling principle in all his plans and efforts. From the cumbersome mass of the single acting steam cylinder, the ponderous beam and counter balance weight, and later the enormous fly wheel, have come the beautiful, symmetrical, compact, strong mechanism composing the structure of the engine of to-day; and instead of a machine requiring the consumption of 10 lbs. or more coal per hour, to produce one horse power, we have the modern high speed, high pressure, compound, condensing, jacketed cylinder, automatic cut-off engine, capable of running with best form of boilers, with 13 lbs. of coal per horse power, per hour. THE SETTING AND CARE OF BOILERS. As so much depends on the structure, setting and care of boilers, to produce favorable results, special attention is given to those points. BOILERS. The horse power of the boilers should be 20 per cent. greater than the maximum power of the engine, and when steam is used for heating and other purposes, a liberal allowance should be made. With the indicator we may determine very closely the performance of the engine; with the boiler it is very uncertain and vague what may be going on in the furnace, and inside the shell we cannot so easily determine. The engineer must depend largely upon his judgment. Close observation may, however, teach much. The Horizontal Return Tubular boiler as the kind most generally used, is referred to here. The mistake is frequently made of crowding the grate up too close to the shell. A vessel of water when held close to the flame of a lamp, will speedily be covered with smoke, and take a longer time to boil than if kept clear of the flame. Therefore, a plenty of room should be allowed for the complete combustion of the products of the fuel, and to prevent a deposit of unconsumed carbon on the relatively cooler surfaces of the boiler. The grates, therefore, should not be less than 25 inches to 30 inches below the shell. If the boiler front will not admit of it they may be pitched back somewhat, but not to exceed 1 inches to the foot. Have grates of such construction as will give abundant air space. |