Page:Popular Science Monthly Volume 92.djvu/741

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��The Wind's Autograph on a Gusty Day

Recorded with a pressure-tube anemometer. The vertical hnes are hour-hnes and the horizontal Hnes show the force of the wind in miles an hour and dlso in pounds a square foot Direction is also indicated

��ground nor the character of the latter. Many a forced landing in foggy weather has ended disastrously in the ocean.

The fog problem will undoubtedly be solved. Probably the radio-compass or some other system of wireless signalling will help the airman keep his bearings, and he will obtain further guidance from aerial buoys, in the shape of captive balloons, floating above the level of all ordinary fogs. Mr. Holt Thomas, in England, has recently proposed the plan of establishing landing grounds at inter- vals of a few miles along the main air routes, their location to be marked with kite-balloons by day and powerful search- lights by night. A better plan would be to fly at each landing place, and wherever else aerial signposts were desired, a string of kite-balloons flying tandem, with a lantern suspended from each balloon. It would thus be possible to attain much greater altitudes than with a single balloon and a searchlight, and hence to provide for fogs of all depths.

Little need be said about the other weather factors in aviation, because they are hardly more serious in their effects than the corresponding conditions of travel on ierra firma. At great altitudes the air is very cold, in summer as well as winter. The carbureter m.ust be shielded against freezing, and the aviator needs the warmest clothing. The airman also needs protection against rain and hail — the

��pelting of which, when one is flying at one hundred miles an hour or more, is un- comfortable, to say the least. Lightning, which is a serious hazard in ballooning, seems to be relatively harmless to the air- man Deposits of ice and snow, besides loading the planes, may hamper the work- ing gear of the machine, though aviators have reported few cases of this kind.

Last, but not least, in the coming age of commercial aviation the weather bureau now maintained by the governments of all civilized countries will enlarge the scope of their activities so as to safeguard air traffic against atmospheric dangers; while the science of weather will, in turn, derive great benefit from the collective wisdom of practical airmen.

��A Thousand Dentists Will Be in the United States Army

DENTISTS are just beginning to come into their own in the Army. Even yet their importance is insufficiently recognized. According to the latest re- ports we are to have only one dentist to every thousand men. Yet there are to be eight horseshoers to every hundred horses. For the two hundred and fifty thousand horses which the government will need, there will twenty thousand horseshoers, while for one million men there will be provided only a thousand dentists.

��Maybe you have special needs. Write to the editor about anything within the scope of the magazine. He will be glad to help you.

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