Heat. One of the remarkable effects of the application of heat to matter is, that the same amount will affect equal weights of dissimilar kinds in different degrees. Thus the amount of heat that will raise 1 pound of water from 100 degrees Fahrenheit to 200 degrees Fahrenheit, will raise 30 pounds of mercury through the same range. The amount that will raise 1 pound of water 1 degree, will raise 14 pounds of air 1 degree Fahrenheit. The capacity of a body for heat is termed its specific heat, and may be defined as the number of units of heat necessary to raise the temperature of 1 pound of that body 1 degree Fahrenheit. The thermal unit, or unit of heat, is the quantity of heat that will raise 1 pound of pure water 1 degree Fahrenheit, or from 39 degrees to 40 degrees Fahrenheit. Latent heat is the quantity of heat which has disappeared from a body owing to an increase of temperature. The sensible heat is that which is sensible to the touch or measurable by the thermometer. EFFECTS OF HEAT UPON BODIES. SUBSTANCE. Cast iron melts at Zinc melts at Lead melts at. Bismuth melts at Tin melts at Tin and bismuth (equal parts) melt at. Tin 3 parts, bismuth 5, and lead 2, melt at.... Mercury boils at.. Linseed oil boils at. Alcohol boils at.. Ether boils at.. Mercury melts at.. Degrees Fahrenheit. 2754 1983 1850 2160 1900 740 594 476 421 283 212 630 600 174 98 39 EXPANSION OF METALS BY HEAT. In raising the temperature of bars of various metals from 32° Fahrenheit to 212° Fahrenheit, they are found to expand nearly as follows: NOTE. The wide variations in the tensile strength are due to the different forms and qualities of the metal tested. In the case of lead, the lowest strength is for lead cast in a mould, the highest for wire drawn after numerous workings of the metal. With steel it varies with the percentage of carbon used, which is varied according to the grade of steel required. Mercury becomes solid at 39 degrees below zero, |