APPLICATIONS OF EVAPORATION, CONDENSATION 37 



3. 1803 : 212-214. Liquid Air Manufactured Ice. 



a. 1802 : 317. Plan of an Ice Plant. 



6. 1805 : 351-354. Cold by Expansion Ice. 



c. 1806 : 370-372. Steam Heating of Buildings. 



d. 1807 : 206-207. Cooling by Evaporation 'Applications. 



e. 1809 : 194-195. Ice Machines. 



Experiment 15. Cooling by Evaporation. 

 Apparatus : Beaker 50 c.c., test tube 6" X f ", syringe bulb 

 with rubber outlet tube, glass tube J" diameter, 6" long. 

 Materials: Ether, alcohol. 



a. Pour a little alcohol on the hand, and wave it. Repeat, 

 using ether. What is the difference ? Why ? 



b. Put 20 c.c. ether in the beaker, and place in it the test 

 tube containing not more than 2 c.c. cold water; gently force 

 air through the ether by means of the bulb, using the glass tube 

 in the ether. The water should freeze in about ten minutes. 



Experiment 16. Heating by Condensation. 



Apparatus: Burner, ring stand, asbestos mat, flask 250 c.c., 

 single-hole rubber stopper to fit flask, glass tube J" diameter, 

 water trap, rubber tube in short pieces to join glass tubing, 

 beaker 150 c.c., thermometer. 



a. Boil water in the flask and pass the steam, by means of 

 the glass and rubber tubing, through the water trap, into 

 100 c.c. water which has a temperature of 41 C., until the 

 temperature becomes 95 C. Measure the water in the 

 beaker. How many grams of water were condensed ? To 

 raise 100 c.c. of water from 41 C. to 95 C. required how many 

 calories ? Divide this number by the number of grams of 

 water which were condensed, and you will obtain the number 

 of calories which each gram of steam gave up while condens- 

 ing. What results did you obtain ? How does this compare 

 with your references? 



