PRIZES FOR THE INVENTOR 



143 



the kitchen fire and the heat given off by 

 the illuminants employed. 



Of course, water can only be heated to 

 the boiling temperature ; but there are 

 many liquids that can be heated to a very 

 much higher temperature than this with- 

 out boiling. I took a tumbler of olive oil 

 and heated it by means of a thin iron 

 wire connected with a voltaic battery. I 

 placed in the tumbler of oil a test-tube 

 filled with water. In a short time the 

 water was boiling, but the oil remained 

 perfectly quiescent. If you store up hot 

 oil instead of water you will have at your 

 command a source of heat able to do all 

 your cooking, and even produce steam 

 power to work machinery. 



We have plenty of heat going to waste 

 in Washington during the summer-time, 

 for the sun's rays are very powerful, and 

 we do not use the roofs of our buildings 

 except to keep off the rain. What wide 

 expanses of roof are available in all our 

 large cities for the utilization of the sun's 

 rays ! Simple pipes laid up on the roof 

 and containing oil or some other liquid 

 would soon become heated by the sun's 

 rays. The hot oil could be carried into 

 an insulated tank and stored. You could 

 thus not only conserve and utilize the 

 heat that falls upon the tops of your 

 houses, but effect some cooling of the 

 houses themselves by the abstraction of 

 this heat. 



THE REASON WE CANNOT KEEP OUR 

 HOUSES COOL 



I was once obliged, very much against 

 my will, I can assure you, to remain in 

 Washington right in the midst of the 

 summer, and the thought kept constantly 

 recurring to my mind, If man has the 

 intelligence to heat his house in the win- 

 ter-time, why does he not cool it in the 

 summer ? We go up to the Arctic regions 

 and heat our houses and live. We go 

 down to the Tropics and die. In India 

 the white children have to be sent home 

 to England in order to live, and all on 

 account of the heat. The problem of 

 cooling houses is one that I would recom- 

 mend to your notice, not only on account 

 of your own comfort, but on account of 

 the public health as well. 



Now, I have found one radical defect 



in the construction of our houses that 

 absolutely precludes the possibility of 

 cooling them to any great degree. You 

 will readily understand the difficulty 

 when you remember that cold air is spe- 

 cifically heavier than warm air. You can 

 take a bucket of cold air, for example, 

 and carry it about in the summer-time 

 and not spill a drop ; but if you make a 

 hole in the bottom of your bucket, then, 

 of course, the cold air will all run out. 



Now, if you look at the typical tropical 

 houses, you will find that they are all 

 open on the ground floor. Supposing it 

 were possible to turn on a veritable Ni- 

 agara of cold air into a tropical house, it 

 wouldn't stay there five minutes. It 

 would all come pouring out through the 

 open places below and through the win- 

 dows and doors. If you want to find your 

 leakage places, just fill your house with 

 water and see where the water squirts 

 out! 



I began to think that it might be pos- 

 sible to apply the bucket principle to at 

 least one room in my Washington home, 

 and thus secure a place of retreat in the 

 summer-time. It seemed to be advisable 

 to close up all openings near the bottom 

 of the room to prevent the escape of cold 

 air and open the windows at the top to 

 let out the heated air of the room. 



MY OWN EXPERIMENTS 



Now, it so happens that I have in the 

 basement of my house a swimming tank, 

 and it occurred to me that since this tank 

 holds water, it should certainly hold cold 

 air ; so I turned the water out to study 

 the situation. The tank seemed to be 

 damp and the sides felt wet and slimy. 



I reflected, however, that the condensa- 

 tion of moisture resulted from the fact 

 that the sides of the tank were cooler 

 than the air admitted. Water vapor will 

 not condense on anything that is warmer 

 than itself, and it occurred to me that if 

 I introduced air that was very much 

 colder than I wanted to use, then it would 

 be warming up in the tank and becoming 

 dryer all the time. It would not deposit 

 moisture on the sides and would actually 

 absorb the moisture there. 



I therefore provided a refrigerator, in 

 which were placed large blocks of ice 



