Page:Popular Science Monthly Volume 91.djvu/914

 Popular Science Monthly

��more like the fashioning of some exquisite musical instrument. Stradivari us never selected the wood for his violins more care- fully than the men who shape the spars for a wing pick their pieces of spruce. Human life depends on the proper choice of wood. No one in an airplane factory "takes a chance" — least of all in building a wing. It takes at least a thou- sand feet of this carefully s e 1 ected spruce to build a single airplane. We must find enough for thousands and thou- sands of ma- chines. To meet the de- mands of present Eng- lish con- struction alone, more spruce is wanted than the entire

��The surveys of the country's manufac- turing facilities made by the National Advisory Board and the Aircraft Produc- tion Board will enable us to avoid most of the mistakes made by England during the early months of the war. Automobile makers and munitions manufacturers must be taught how to produce good trustworthy

engines and

���irown and Dawson

The fabric of an airplane wing must be as tight as a drum- head. It is therefore stretched to its limit of endurance and coated with a preparation termed "dope," a nitrocellu- lose compound which is thus far the best coating discovered

��cylinders ; f u rniture makers and coach build- ers must learn how to make wings to which hu- man lives may be trusted ; sew- ing machine and type- writer com- panies must also coop- erate if we are to turn out 3,500 machines a month. Eng- land has

��present annual output of the United States.

Perhaps the most serious problem with which we are confronted in building whole flocks of battle eagles within the time de- manded by our allies is the necessity of air- drying the spruce. The wood cannot be used as it comes from the forest and the mill. It must be seasoned, preferably air- seasoned, a process that requires about nine months. The Bureau of Standards is at work on the problem of devising a means of so treating the wood that it can be used in building wings soon after it is cut ; but even such research takes time. Some efforts have been made to use steel. Perhaps our salvation may lie in that procedure. Air- plane builders, for the most part, prefer spruce to steel; it is lighter and stronger per pound.

The difficulties of building 23,000 air- planes in a year or less, difficulties inherent in the very nature of the flying machine as well as in the scarcity of material are not dis- heartening. Automobile production meth- ods must be adopted ; which means minute subdivision of manual and machine work, and above all standardization. Factories must concentrate on one or two types.

��taught us the way. At present no fewer than one thousand British factories are en- gaged in making parts for flying machines.

The Aircraft Production Board has done invaluable work in standardizing the air- plane. The wonderful Liberty engine has been created — the composite invention of the foremost authorities on metals, radiators, cooling, carburetion, and ignition. The Board will determine the sizes of nuts and pins and wires. They vary now. It should be possible to build an airplane on the battlefield from the parts of several old ma- chines. How can that be done if a bed will receive only a certain size and type of engine, if nuts will not screw on the bolts at hand, if, in a word, parts cannot be inter- changed ?

There are far too many types of airplanes now. France entered the war with no less than thirty. Of course she could not fore- see in 1914 that half a dozen would suffice, simply because the half dozen that have been developed are utterly different from the thirty that marked the pinnacle of achievement in 1914. Standardization sometimes means stagnation ; but military exigencies will prevent that at this time.

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