Popular Science Monthly 



167 



A Windmill Which Always Turns in 

 the Same Direction 



WHEN the wind strikes a surface 

 inclined at an angle to the direc- 

 tion of the wind, the surface is displaced 

 in a direction that depends upon the de- 

 gree of inclination. Upon this well- 

 known principle sailboats, windmills, 

 and aeroplanes are built. When the 

 wind comes in an opposite direction — 

 that is to say, strikes the surface on the 

 other side — it tends to displace it in the 

 opposite direction. It would seem then 

 to be impossible so to place a surface 

 that it shall always move in the same 

 direction no matter whence the wind 

 comes. A French windmill maker, how- 

 ever, has succeeded in solving the prob- 

 lem. He makes a horizontal windmill 

 with perpendicular vanes and axis re- 

 volved by the planes without gearing. 



The vanes are formed of many sheets 

 of iron arranged in the form of a wheel. 

 The wind on entering the wheel passes 

 between the plates and produces motion, 

 and the wind on issuing, dips along the 

 general slope of the vane and produces 

 motion in the same direction. 



The wind is thus utilized going and 

 coming. A\'hen the vanes are properly 

 inclined, the power produced by this 

 strange windmill is high, and the wind 



The roll of tape is sixty feet long. On 



it is written one of the longest letters 



ever mailed for two cents 



Puzzling windmill which always tiims in 



the same direction, no matter how the 



wind is blowing 



that reaches nine-tenths of the wheel's 

 diameter is set to work, no matter in 

 what direction it is blowing. 



An Island Made to Order 



Hx^W'AHAN soil is being used to 

 build up the small coral island in 

 the Pacific Ocean known as the Midway 

 and used as a relay station by a trans- 

 Pacific cable company. A quantity of 

 earth is taken there every three months 

 by the schooner that is sent with food 

 supplies for the operators. The task of 

 building the island has progressed so far 

 that if is now possible to keep a cow on 

 the pasture. 



The Longest Letter in the World 



YOUR friends are always asking for 

 long letters. To supply this demand 

 a man in Los Angeles, California, has 

 invented a little novelty that has cap- 

 tured the fancy of visiting tourists. 



It consists of a roll of paper tape sixty 

 feet long. The paper is made to write 

 on, and has a place for the name and 

 address of the sender and receiver. It 

 goes as first class mail for two cents, 

 like any other letter, and can be mailed 

 in any mail box. 



These little "long letters" cause many 

 a laugh and one can write a regular 

 letter on the tape, by merely unrolling 

 it as it is used up. 



