The October Issue of The Popular 

 Science Monthly 



What the War Has Done Harnessing the Sun 



For the Aeroplane in Egypt 



The hiitlk'field is to the aero- The sua is hot. Every boy 

 iiautie engineer a huge hiboratory knows that who lias ever used a 

 for the testing of aeroplanes. More burning glass. Isn't there some 

 progress has been made in design- way of heating water with the 

 ing flving machines since the war 

 began than most of us imagine. 

 Wouldn't you like to know just 

 what the war has done to bring v.s 

 measurably nearer the day when about the wonderful \)\nn of a 

 we will trundle out a flying ma- Philadelphia inventor to harness 

 chine as easily as if it w^ere an the sun. 

 automobile and whirr away from 

 our country homes to our offices? 

 The October issue will tell you. 



HandHng New York City's 

 Traffic in a New Way 



sun and driving a steam engine — 

 some way of putting the sua to 

 work? The PopuLAit Science 

 Monthly for October will tell all 



Motoring on Roller-Skates 

 From Home to Office 



It sounds fantastic, but inventors 

 have been so successful in motoriz- 

 ing the roller-skate that before long 

 New York, the greatest city of it will l)e possible to skate your 

 the Western Hemisphere, is a way to work each morning. Read 

 little, long island, packed with about it in the October issue. 



people, trolley cars, wagons, dwell- 

 ings and office buildings. It has 

 the most difficult traffic problem 

 in the world. To handle the 

 millions and millions of tons of 



In the same issue and regularly 

 thereafter you are to be informed 

 of the latest happenings in the 

 great field of astronomy. 



These are only a few of the 



freight brought in by steamships articles which are to appear. Re- 



and railways, a crude and anti- 

 (juated system is still in vogue. 

 In the next issue of the Poptlar 

 Science ^Monthly we will tell 

 how great engineers propose to 

 solve this traffic problem scien- 

 tificallv. 



member that each month there 

 are three hundred articles and as 

 many pictures — all intensely in- 

 teresting, all dealing with new 

 things in science and invention 

 which you ought to know to keep 

 abreast of these stirring times. 



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