Popular Science Monf/ih/

���I Kadol anil Ili'rbirt

��Army reconnaissance observers study enemy airdromes, make a note of the number of han- gars and planes on the ground and watch the movements in towns and large encampments

��broken by shell fire he sees smudges and spots, all of which are faithfully recorded.

Camouflage or a Battery — Which?

The shells come thick and fast, but the pilot is an old hand at the game; he'll stick till the work is done. Cleverly hidden on the ground, the observer sees some small narrow-gage tracks, terminat-

��ing in several pits. Has he discovered a new enemy battery, or is it camouflage? He must see the gun flashes before being sure. There they are! One! Two! Three! P'our! Five! He also sees the blast marks in front of the battery. Now he is satisfied. Signalling the pilot he focusses his glasses again^ this time in the direction of home.

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