Portion of 9880 Horse-power Installation of Babcock & Wilcox Boilers and Superheaters, Equipped with Babcock & Wilcox Chain Grate Stokers at the South Side Elevated Ry. Co., Chicago, Ill.

FOOTNOTES

[10] See Scientific American Supplement, 624, 625, December, 1887.

[11] 460 degrees below the zero of Fahrenheit. This is the nearest approximation in whole degrees to the latest determinations of the absolute zero of temperature

[Pg 96]

PROPERTIES OF WATER

Pure water is a chemical compound of one volume of oxygen and two volumes of hydrogen, its chemical symbol being H 2 O.

The weight of water depends upon its temperature. Its weight at four temperatures, much used in physical calculations, is given in [Table 10] .

[TABLE 10]
WEIGHT OF WATER AT TEMPERATURES
USED IN PHYSICAL CALCULATIONS
Temperature Degrees
Fahrenheit 		Weight per
Cubic Foot
Pounds 		Weight per
Cubic Inch
Pounds
At 32 degrees or freezing
point at sea level 		62.4180.03612
At 39.2 degrees or point of
maximum density 		62.4270.03613
At 62 degrees or standard
temperature 		62.3550.03608
At 212 degrees or boiling
point at sea level 		59.8460.03469

While authorities differ as to the weight of water, the range of values given for 62 degrees Fahrenheit (the standard temperature ordinarily taken) being from 62.291 pounds to 62.360 pounds per cubic foot, the value 62.355 is generally accepted as the most accurate.