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. 



.^^ 



Light penetrates through 

 the ruby glass in the cover 

 c fthe collapsible chamber 



