------+------------
Common salt, 1 part; snow, 3 parts | 32 | zero .0
Common salt, 1 part; snow 1 part | 32 | -.4
Calcium chloride, 3 parts; snow 1 part | 32 | -27
Calcium chloride, 2 parts; snow 1 part | 32 | -44
Sal ammoniac, 5 parts; salt-peter 5 parts; | |
water 16 parts. | 50 | -10
Sal ammoniac, 1 part; salt-peter 1 part; | |
water 1 part | 46 | -11
Ammonium nitrate, 1 part; water 1 part | 50 | -3
Potassium hydrate, 4 parts; snow 3 parts | 32 | -35
-----------------------------------------------+---------+------------

IGNITION TEMPERATURES.

Phosphorus 120 degrees Fahrenheit
Bi-sulphide of carbon 300 " "
Gun-cotton 430 " "
Nitro-glycerine 490 " "
Phosphorus, amorphous 500 " "
Rifle powder 550 " "
Charcoal 660 " "
Dry pine wood 800 " "
Oak 900 " "

POWER AND HEAT EQUIVALENTS.

In studying matters pertaining to power and heat, certain terms are
used, such as horsepower, horsepower-hours, watts, watt-hours, kilowatt,
kilowatt-hours, foot-pounds, joule, and B. T. U. (British Thermal Unit).

The following tables give a comprehensive idea of the values of the
different terms:

1 Horsepower-hour = 0.746 kilowatt-hour = 1,980,000 foot-pounds
of water evaporated at 212 degrees Fahrenheit,
raised from 62 degrees to 212 degrees.

1 Kilowatt-hour = 1,000 watt-hours = 1.34 horse-power-hours
= 2,653,200 foot-pounds = 3,600,000 joules
= 3,420 B. T. U. = 3.54 pounds of water evaporated
at 212 degrees = 22.8 pounds of water raised from
62 to 212 degrees.

1 Horsepower = 746 watts = 0.746 kilowatts.= 33,000 foot-pounds
per second = 2,550 B. T. U. per min. = 0.71
B. T. U. per second = 2.64 pounds of water
evaporated per hour at 212 degrees.

1 Kilowatt = 1,000 watts = 1.34 horsepower = 2,653,200
foot-pounds per hour = 44,220 foot-pounds per
min. = 737 foot-pounds per second = 3,42