Page:Popular Science Monthly Volume 92.djvu/59

 Popular Science Monthly

��Pulling Horses Out of the Mud in Rain-Soaked Flanders

WHERE is the muddiest country in all the world? Put this question to the Allied troops and they will tell you as one man that it is in Flanders, the land that was noted for its fertility and beauty before the war, but which is now the scene

of desolation ^

and plunder. Theillustration showsa Tommy extricating two shell-laden horses mired in the mud. Fre- quently a burst- ing shell will cause a number of horses to leave a good road and run for the soggy fields, only to become help- less.

��What Makes the Tumbler Pigeon Tumble in Flight?

'"T^HE action of the tumbler is well J_ known to nearly everyone. In its simplest form it is a single backward somersault, made in flight, and from which the bird recovers gracefully. This may be increased to two or three turns in . the common

���© Pn-ss lUus. Serv.

Two horses, laden with the famous French "75's," being pulled out of the knee-deep mud in Flanders

��With This Darkroom, Develop Your Photographs on the Spot

THE modern photographer can develop his pictures wherever he happens to be. The device that makes this possible is a collapsible dark chamber. A large light-proof cover opens at the top through which you place the trays, the plates and chemicals. The chamber is extended by a bracing which can be raised about one foot. Your arms are

put through two y

light-excluding sleeves. Your head is brought up against a hood, and two shutters are opened automatic- ally. You proceed with your work with ease, developing films as well as plat93

����tumbler or to a swift succession of four or more in the roller. .... That it (the tumbler) has a physio- logical cause, such as a defect- ive inner ear or brain, there can be no doubt, but the prob- 1 e m is so clouded with what appear to be psychologi- cal questions that it will not be easily solved. At any rate the facts remain that the .bird does go over, that he does it more freely at times, as when flying with his mate, and that under stress of necessity, when pursued by a hawk or striving to regain his place in the kit, he flies as well as any pigeon. On the other hand, some individuals in the bird family, particularly among the rollers, appear to lose control of themselves entirely, and having started to roll, continue until they strike some object

\ which stops their

fall. Such birds, which are known as 'roll-downs,' or 'mad rollers,' never regain the ability to fly safely once they have lost it." (L. S. Crandall, in Pels, Henry Holt & Co., New York.) Test- ing the sense of balance is the main feature of the pres- ent examination of prospective flyers.

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��Light penetrates through the ruby glass in the cover c fthe collapsible chamber

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