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 ar