148 Domestic Science 



To this must be added 32 F., giving as a result 

 185F. 



(6) Subtracting 32 F. from 15 F. gives - 17 F. 

 - 17 F. = - (17 x T 8 go) R. - - 7-6 R. 



94. We have already spoken of heat being trans- 

 mitted from one body to another, and one's daily 

 experience is sufficient evidence that this transfer 

 actually takes place. We have not yet considered, 

 however, under what circumstances heat may thus be 

 transferred. A little thought will convince one that 

 it takes place whatever the materials, the sizes, the 

 densities, and the physical states of the bodies. Thus 

 a small body will give up heat to, or receive heat 

 from, a larger one a liquid may receive heat from, 

 or supply heat to, a solid and so on. The condition 

 which must be fulfilled in order that heat may pass 

 from one body to another is that they must be at 

 different temperatures, i.e. one body must be warmer 

 than the other. We are thus led to formulate the 

 usual definition of temperature as follows : 



The temperature of a body is its condition with 

 reference to its capacity for receiving heat from, or 

 supplying heat to, other bodies. Those bodies from 

 which it receives heat are said to possess a higher 

 temperature than the body itself, those which it 

 supplies with heat are at a lower temperature, and 

 those which neither receive nor supply heat are said 

 to be at the same temperature. 



The interchange of heat is however regarded as a 

 continuous process, and as going on between bodies at the 

 same temperature as well as between those at different 

 temperatures. In the latter case, however, the amounts 

 of heat received and supplied by either body are equal, 



