LIQUEFIED AIR. 



LITERATURE, AMERICAN, IN 1898. 365 



tube may be attracted by an electro magnet, as if it 

 were a piece of iron. 



Applications. Liquid air is not yet manufac- 

 tured commercially, and is not on the market. Mr. 

 Tri pier's laboratory in New York is probably at 

 present the only place in the United States where it 

 can be obtained in quantities sufficient to perform 

 the experiments described above. But there seems 

 no reason to doubt that it can be produced in as 

 large amounts as desired, and that it will be for sale 

 in the near future. All sorts of applications have 

 been foreseen for it, but no one of them has yet 

 been put on a practical basis. They depend chiefly 

 on the three properties enumerated above namely, 

 the low temperature of the liquid, the pressure of 

 its vapor, and its high proportion of oxygen. 



The low temperature of the liquid naturally sug- 

 gests its employment for refrigerating. It has 

 been suggested that it may be distributed in pipes, 

 or that an open vessel containing it may take the 

 place of a huge lump of ice in refrigerators. The 

 impossibility of confining the air and the rapidity 

 of its evaporation seem at present obstacles to the 

 practical realization of these plans. Another plan 

 for utilizing the low temperature of the air depends 

 on the fact that the resistance of metallic conduct- 

 ors to electricity decreases as their temperature 

 falls. It has been stated that at the temperature 

 of the liquid a copper conductor of moderate size 

 could be used to transmit to New York the energy 

 of Niagara. At this temperature pure copper be- 

 comes fifteen times and pure iron twenty-three 

 times as good a conductor as under ordinary cir- 

 cumstances. The liquid is also a fine insulator, so 

 that, if an induction coil were immersed in it, the 

 resistance of the coil would become enormously 

 smaller and at the same time its insulation would 

 probably be improved. Very low temperatures 

 have recently been used in a variety of applications, 

 as in the purification of chloroform and similar 

 liquids by freezing, the treatment of alcoholic 

 liquors, and even in the cure of certain diseases ; 

 and liquid air may prove a convenient and eco- 

 nomical means of obtaining the temperature desired 

 for such purposes. 



The great pressure developed by the liquid when 

 confined seems to some to promise a great future 

 for it as a motive fluid. The trouble is that this 

 pressure is so high as to be almost uncontrollable 

 and explosive. If the liquid is kept in a closed tank 

 the tank must be fitted with a safety valve which 

 shall not allow the pressure to rise above a certain 

 degree, and this would involve continual " blow- 

 ing off," with loss. As the product of the liquid's 

 evaporation under such conditions is ordinary com- 

 pressed air, which has long been used for motors, 

 there is no doubt that it could be so used in this 

 instance, but whether the liquid air would be the 

 cheapest source of compressed air may be doubted. 

 The " Engineering News " (New York, April 14, 

 1898) considers it possible that liquid air will have 

 a large use for power storage, since, although its 

 employment would be more expensive than present 

 systems, and would return a smaller proportion of 

 the power originally applied, it has the advantage 

 of compactness. Liquid air occupies only about one 

 fourth the space of air at 2,500 pounds' pressure. 

 In a pound is stored 139,000 foot pounds of energy, 

 the equivalent of 4J horse power exerted for a 

 minute. The writer estimates that only one tenth 

 to one twentieth this amount of energy to the pound 

 can be stored electrically, and only one fourth by 

 heated water. The estimates made by this writer 

 suppose a high degree of perfection in methods, and 

 represent future possibilities rather than present 

 results. Others regard his figures as too sanguine, 

 and are not inclined to believe that liquid air will 



BURNING STEEL IN 

 LIQUID OXYGEN. 



ever be used in the way he suggests. If it is, it will 

 doubtless be so used only where small bulk is of 

 paramount importance, as in motor carriages or in 

 torpedo propulsion. 



The richness of liquid air in oxygen may be util- 

 ized in two ways: 1. By allowing the nitrogen to 

 boil off and then collecting the gas from the residue, 

 very pure oxygen can be obtained, and it is possible 

 that this method may at some future time be em- 

 ployed commercially. 2. The liquid mixed with a 

 combustible forms a high explosive, and it has been 

 proposed by Prof. Ewing, in a paper before the Lon- 

 don Society of Arts (March 2, 1898), to use it prac- 

 tically in this way. He would 

 pour the liquid, containing 40 

 to 50 per cent, of oxygen, on 

 bits of wood charcoal 0.0001 

 to 0.0002 cubic inch in size. 

 These are made into a sort of 

 sponge by mixture with about 

 one third their weight of cot- 

 ton wool. In fifteen to thirty 

 minutes all explosive power 

 disappears by the evaporation 

 of the liquid air, and it is only 

 by inclosing the material in 

 thick cartridge cases of paper 

 that it is made to last as long 

 as this. The explosive must 

 therefore be mixed at or near the place where it is 

 to be used. Satisfactory trials have been made near 

 Munich, Bavaria, and it is claimed that even the 

 fact that the mixture loses its explosive power so 

 soon has the advantage that there can be no danger 

 from unexploded charges, or from its use by crimi- 

 nals. If used, however, it will probably be found 

 convenient chiefly where a considerable amount of 

 blasting is to be done in one place, as in large quar- 

 ries. It has also been proposed to employ the liquid 

 air in diving operations, as a diver could easily carry 

 a quart of the liquid, and this would furnish by 

 evaporation 1,000 times its volume of gaseous air. 



The effect of liquid air on living organisms does 

 not seem to be as injurious as might be expected 

 from its very low temperature. D'Arsonval (Paris 

 Biological Society, June 9, 1898) says that, in ex- 

 periments upon the action of liquid air on living 

 tissues and membranes, he finds that actual contact 

 does not take place, and that the liquid can even be 

 swallowed. On drinking the liquid (about one tenth 

 of a gill) mixed with champagne the stomach is at 

 first distended, but is at once relieved by eructation. 

 M. D'Arsonval kept bacilli in liquid air six days, 

 and found that they were then still alive and ca- 

 pable of growth. 



LITERATURE, AMERICAN 7 , IN 1898. Only 

 42 fewer books were published during the year than 

 in 1897, although the outlook for the publishing 

 houses was far from favorable in the beginning of 

 the year ; thus 4,886 books are recorded, against 

 4.928 of last year, though it is to be taken into con- 

 sideration that but 2,908 of these were by American 

 authors, against 3,318 the work of native genius in 

 1897. Of books by English and other foreign 

 authors (including new editions) 834 were manu- 

 factured in this country, compared with 495 last 

 year, and the importations of books bound or in 

 sheets were respectively 1,144 against 1,115. As a 

 whole, the year showed a lower number of books 

 published than any year since 1894. when 4,484 

 titles were recorded. The most marked increase 

 shown in any department was, strange to say, in 

 that of poetry. One hundred and eight more new 

 books of poetry were sent out in 1898- than in 1897, 

 and the number of new editions was considerably 

 less. The quality, it may be observed, did not im- 

 prove with the increase of quantity. More works 



