EXPERIMENTS. FALL 

 OF TEMPERATURE 



(a) Put a conven- 

 ient quantity of very 

 hot water into a ves- 

 sel provided with a 

 close-fitting one- 

 holed stopper through 

 which a thermometer 

 passes. 



(b) Put the same 

 quantity of equally 

 hot water into a simi- 

 lar vessel covered with 

 cotton batting or felt. 



Note and record 



every three minutes 



V 



70 



60 



BO 



FIG. 8. The water in the covered vessel cools more 

 slowly than the water in the unprotected vessel. 



for half an hour the 

 temperature of the water 

 in the two vessels, and 

 draw curves to indicate 

 the changes in tempera- 

 ture. See Experiment 2. 

 Explain the great dif- 

 ference in the two 



O 15 30 45 60 



1 space on oy=2C 

 1 space on ox =3 Minutes of time 



FIG. 9. 



Temperature curves of the covered 

 and uncovered vessels. 



curves. 



What practical appli- 

 cation is made of the fact 

 that the fall in tempera- 

 ture can be made to take 

 place very slowly in the 

 covered vessel? 



