VOL.8. No. 6
1043
LIQUID AIR
storage tanks for liquid oxygen, each holding 1000 gallons, this oxygen to be used in explosives. Liquid oxygen is sometimes carried by aviators to supply the oxygen needed by man and occasionauy by engines at very high altitudes. One very important application for liquid air is its use as an aid in research. I t is a very useful agent for this purpose, largely because of its low temperature. If temperatures no lower than -78.5'C. are needed they may be secured more economically by dry ice than by liquid air. We may safely predict that liquid air will never be used extensively for ordinary refrigeration nor for the transmission of power, because it is too expensive and too inefficient.
Cemented Shoes. For over fifteen years, shoes have been made in Europe with cement taking . the place of stitching for the attachment of the sole. Every little while, a flurry is created in this country when it is announced that a cemented shoe is about to be made here. Not a few imagine that this type of shoe will rrvulutionire some branches of shoe manufacture and perhaps greatly cheapen shoes. It now appears that the shoe with cemented-on sole bas actually found its place in America. It does not promise to attain the proportions of a revolution. It is entering the field here as an interesting variation in the art, rather than as part of a radical and new system of shoe-building. The cementingon process appears to be best suited for McKay shoes, hut is also applicable. with modifications. to turn shoes and even to welt sboes. Its present and most natural field is for women's "high-style" sboes. nto remove and re-insert the last during With the cemented shoe it is not y the shoe-building process, as it is with McKay and turn shoes. Consequently, the folds and wrinkles so hard to avoid when the last is disturbed, are avoided, and lining, insole, upper, and outsole are virtually molded into shape. Such excellent shaping makes thi; type of construction desirable for ladies' light-weight and novelty shoes. A distinct advantage of the cementedon solc, besides the excellent shaping and fit which are more or less characteristic of the method, is that no btaining or injurrng of the leather or lining can take place since the shoe is built ~ J Y throughout. A disadvantage of the cementing pmess is that i t calls for the use of more upper leather than does stitehing, to give sufficient surf-for adhesion to the sole. Sole leather can be suitably flexed and otherwise handled and treated t o give a pliable. comforteble shoe. The parts of the leather to be cemented must be specially huffed to produce a surface of maximum -mio. the manufachvina - and care is needed throurrhout - -proeess to insure gaad adhesion. With good workmanship, a satisfactorily strong shoe is produced. Some features of cemented construction are cheaper than corresponding features of stitched construction and some are more expensive, taking all things into account. The complete eost of the cemented-sole shoe need not be greatly different from that of the stitched shoe, although the present practice appears t i be make the fander grades a t relatively higher cost levels. Whether or not the shoe with cemented-on sole will 6nd more than a temporary or a nominal place in the art will depend perhaps most of all on customer acceptance. The shoes are stylish and comfortable, but it remains to be reen whcthcr or not cemented conswuctiun, when known to be such, will be considered as the psychological equivalent of stitching.-Id. Bd.of Arthur D. Lit&. Inc. ~
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