Popular Science Monthly 



919 



amount of mercury vapor is left between the 

 walls, it will be solidihed and deposited 

 upon the walls of liie vessel upon the 

 entrance of a liquid gas. In this manner it 

 acts as a mirror and reflects heat wa\-e3 

 that impinge upon the outer surface of the 

 container. Thus was the familiar commer- 

 cial vacuum bottle created. 



Now that the methods for producing low 

 temperatures have been explained, we will 

 briefly review some of the more wonderful 

 phenomena that occur when matter is sub- 

 jected to such severe low temperatures. 



Strange Things That Happen When 

 Gases Are Liquefied 



If a piece of silver forming part of an 

 electrical circuit is immersed in liquid air 

 and held there, it undergoes a physical 

 modification that reduces its electrical re- 

 sistivity to an almost unnoticeable amount. 

 It was predicted by physicists that at abso- 

 lute zero a metallic substance would offer 

 no resistance to an electrical current. 



Professor 

 Dewar discov- 

 ered that if a 

 magnet was re- 

 peatedly im- 

 mersed in liq- 

 uid air, its 

 magnetic influ- 

 ence was not 

 only intensified 

 but perma- 

 nently increas- 

 ed. Also, curi- 

 ously enough, 

 oxygen ma>' be 

 separated from 

 the nitrogen in 

 liquid air by 

 magnetic 

 means. 



A student of 

 physics would 

 naturally ask: 



tures red things become yellow and yellow 

 tilings white and so on. 



It has been found that if a bell con- 

 structed of pure lead is subjected to such a 

 low temperature, it has a pure metallic 

 ring when struck a sharp blow. Bits of 

 vegetable matter immersed in liquid air 

 become so hard and brittle that they may 

 be powdered in a mortar. In the labora- 

 tory of the British Royal Societv, it was 

 found that the bacteria cculd not be de- 

 stroyed even by the lowest temperatures. 



The "absolute zero" has been set by 

 physicists as being 273° Centigrade below 

 zero (459.4° Fahrenheit below zero). In 

 this condition matter will have absolutely 

 no heat. The nearest approach to this has 

 been in the liquefaction of hydrogen or 

 ^254° Centigrade ( — 425.2° Fahrenheit). 



A 



Love in an L.banuoncd lailv 



an upstairs and a guestroom in this improvised home 



Will a liquid gas alter the 

 color or light-absorption of a substance? 

 The answer is, yes. Understanding, as we 

 do, that the color of a substance depends 

 upon the wavelength of the ether waves 

 of the spectrum it absorbs, it would be 

 natural and tempting for one to conclude 

 that it was the great contraction of the mole- 

 cules that affected its wave absorption at 

 this temperature. We must be more cau- 

 tious than positive in making this pretty 

 assertion as final at this time. It has been 

 found, however, that at these low tempera- 



Transforming a Railroad Water -Tank 

 into a Home for Two 

 X OLD water -tank in a Western 

 town stood idle until an enterprising 

 citizen came 

 along and rec- 

 ognized in it 

 the making of 

 a home for 

 himself and his 

 wife. 



He set to 

 wcrk with car- 

 penter's tools, 

 and in a week 

 he had the in- 

 terior fitted up 

 comfortabK-. 

 He cut win- 

 dows where he 

 wanted them 

 and made a 

 door large 

 enough for the 

 champion tall 

 man in the 

 through without 



Wcler Lalll-; 



There is even 



ralk 



United States to 

 ducking his head. 



To disguise the tank-home as far as pos- 

 sible and also to add an element of archi- 

 tectural beauty^ to the whole, he fitted the 

 roof with extensions, placing windows in 

 the extremities. 



This gave him the happy thought of 

 building an upper room to the structure. 

 Now he has plenty of room for guests, since 

 he has finished off and furnished the ad- 

 dition as a spare chamber. A chimney was 

 also added and stoves were installed. 



