Page:Popular Science Monthly Volume 92.djvu/391

 Popular Science Monthly

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��farther and farther into France in spite of all their fuel-wasting efforts. One vessel had been ignited in the air by an anti- aircraft battery into the range of which it had blundered. One senselessly kept on flee- ing until it was liter- ally swallowed up by the Mediterranean. Two wisely landed and surrendered. One of them was the L-49 which was so oddly prevented from hiding its secret by self-de- struction; the other was reduced to a mere mass of wreckage by its commander. A

fifth, of uncertain iden- dity, is supposed to have gained Switzer- land (possibly Fried- richshafen) in a dam- aged condition.

An Immense, Naked Hull of Perfect Form

The marvelous prog- ress in design revealed by the L-49 is apparent to anyone who is at all familiar with the evolu- tion of the Zeppelin. Her perfection lay in

���Machine-gun of the commander's cabin of the super-ZeppeUn L-49

��her simplicity. Speed is the life and soul of a Zeppelin — a speed that is never less than sixty miles an hour and may be as much as one hun-

���A pile of Zeppelin fuel tanks. The airships must carry much fuel because of long trips and exigencies met with

��dred. Speed saves the Zeppelin from destruction in a gale. And speed hag been obtained by trebling the size and by applying the lessons learned in developing the one-hundred-and- thirty-mile-an-hour fighting airplane.

In an airplane, it will be remembered, wires and struts are elimin- ated wherever possible; they offer too much resistance to the wind. The aviator is seated in a beautifully mod- eled boat-like body which parts the air with little disturbance, thanks to its stream- line form. The rud- ders are as simple as possible. All the les- sons which the war has taught the airplane de- signer have borne fruit in the L-49. There is the same inclosing of mechanical and struc- tural parts, the same streamlining every- where, the same sim- plification of rudders, the same reduction of surface and friction, the same disregard of mere bulk, provided it is correctly designed. As the drawing shows, the L-49 is but a naked, immense fish-shaped envelope of perfect stream-line form, with single monoplane fins and rudders, and with absolutely no appendages save four cars, each entii'ely enclosed and each torpedo- shaped. Only a rigid hull permits such ultra-refinement of form. Here we have an- other parallel with the de- velopment of the airplane. As the number and rigidity of the ribs in an airplane was increased, so all types of dirigibles have ceded their place to the Zeppelin despite opposition — all for perfectly good and practical reasons. The smooth, clean sweep of the craft was broken on the

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