Part 41

[Footnote 50: Temperatures are average over one cycle of operation and may vary widely as to maximum and minimum.]

[Footnote 51: Dependant upon length of kiln.]

[Footnote 52: Results secured by this method will be approximately correct.]

[Footnote 53: See "Chimneys for Crude Oil", C. R. Weymouth, Trans. A. S. M. E., Dec. 1912.]

[Footnote 54: To determine the portion of the fuel which is actually burned, the weight of ashes should be computed from the total weight of coal burned and the coal and ash analyses in order to allow for any ash that may be blown away with the flue gases. In many cases the ash so computed is considerably higher than that found in the test.]

[Footnote 55: As distinguished from the efficiency of boiler, furnace and grate.]

[Footnote 56: To obtain the efficiency of the boiler as an absorber of the heat contained in the hot gases, this should be the heat generated per pound of combustible corrected so that any heat lost through incomplete combustion will not be charged to the boiler. This, however, does not eliminate the furnace as the presence of excess air in the gases lowers the efficiency and the ability to run without excess air depends on the design and operation of the furnace. The efficiency based on the total heat value per pound of combustible is, however, ordinarily taken as the efficiency of the boiler notwithstanding the fact that it necessarily involves the furnace.]

[Footnote 57: See pages 280 and 281.]

[Footnote 58: Where the horse power of marine boilers is stated, it generally refers to and is synonymous with the horse power developed by the engines which they serve.]

[Footnote 59: In other countries, boilers are ordinarily rated not in horse power but by specifying the quantity of water they are capable of evaporating from and at 212 degrees or under other conditions.]

[Footnote 60: See equivalent evaporation from and at 212 degrees, page 116.]

[Footnote 61: The recommendations are those made in the preliminary report of the Committee on Power Tests and at the time of going to press have not been finally accepted by the Society as a whole.]

[Footnote 62: This code relates primarily to tests made with coal.]

[Footnote 63: The necessary apparatus and instruments are described elsewhere. No definite rules can be given for location of instruments. For suggestions on location, see A. S. M. E. Code of 1912, Appendix 24. For calibration of instruments, see Code, Vol. XXXIV, Trans., A. S. M. E., pages 1691-1702 and 1713-14.]

[Footnote 64: One to two inches for small anthracite coals.]

[Footnote 65: Do not blow down the water-glass column for at least one hour before these readings are taken. An erroneous indication may otherwise be caused by a change of temperature and density of the water within the column and connecting pipe.]

[Footnote 66: Do not blow down the water-glass column for at least one hour before these readings are taken. An erroneous indication may otherwise be caused by a change of temperature and density of the water within the column and connecting pipe.]

[Footnote 67: For calculations relating to quality of steam, see page 129.]

[Footnote 68: Where the coal is very moist, a portion of the moisture will cling to the walls of the jar, and in such case the jar and fuel together should be dried out in determining the total moisture.]

[Footnote 69: Say ½ ounce to 2 ounces.]

[Footnote 70: For methods of analysis, see page 176.]

[Footnote 71: For suggestions relative to Smoke Observations, see A. S. M. E. Code of 1912, Appendix 16 and 17.]

[Footnote 72: The term "as fired" means actual condition including moisture, corrected for estimated difference in weight of coal on the grate at beginning and end.]

[Footnote 73: Corrected for inequality of water level and steam pressure at beginning and end.]

[Footnote 74: See Transactions, A. S. M. E., Volume XXXIII, 1912.]

[Footnote 75: For methods of determining, see Technologic Paper No. 7, Bureau of Standards, page 44.]

[Footnote 76: Often called extra heavy pipe.]

[Footnote 77: See Feed Piping, page 312.]

[Footnote 78: See Superheat Chapter, page 145.]

[Footnote 79: See Radiation from Steam Lines, page 314.]

[Footnote 80: D, the density, is taken as the mean of the density at the initial and final pressures.]

[Footnote 81: Diameters up to 5 inches, inclusive, are _actual_ diameters of standard pipe, see Table 62, page 308.]

[Footnote 82: Diameters up to 4 inches, inclusive, are _actual_ internal diameters, see Table 62, page 308.]

[Footnote 83: H. P. Jordan, "Proceedings of the Institute of Mechanical Engineers", 1909.]

[Footnote 84: "Zeitschrift des Vereines Deutscher Ingenieur", 1909, page 1750.]

[Footnote 85: Heinrich Gröber--Zeit. d. Ver. Ing., March 1912, December 1912. Leprince-Ringuet--Revue de Mecanique. July 1911. John Perry--"The Steam Engine". T. E. Stanton--Philosophical Transactions, 1897. Dr. J. T. Nicholson--Proceedings Institute of Engineers & Shipbuilders in Scotland, 1910. W. E. Dally--Proceedings Institute of Mechanical Engineers, 1909.]

[Footnote 86: Proceedings Royal Society, Vol. LXXI.]

[Footnote 87: Zeitschrift des Vereines Deutscher Ingenieur, 1910, page 1154.]

[Footnote 88: Proceedings Institute of Engineers and Shipbuilders, 1910.]

[Footnote 89: Natural or Hyperbolic Logarithm.]