50 



THE WORLD'S ADVANCE 



center for the circulation of air and a 

 triangular body beneath is used. In two 

 of the illustrations Perkins is shown 

 above the Allegheny River at Pittsburgh, 

 and testing the lift from a float towed 

 by a river steamer. In the latter in- 

 stance five lifting kites were on the line 

 above the one shown: The ropes in the 

 view showing him aloft are guide ropes 

 which help to steady the line when land- 

 ing. The third illustration shows the 

 first leading kite, which has a ten- foot 

 side, being sent up from the stern of the 

 battleship Pennsylvania when cleared for 

 action. Some of the lifting kites are 

 1 8 feet long. 



The experimenter's most important 

 work was done on the Pennsylvania from 

 January 24 to February 4, 1911, when he 

 made a 5OO-mile cruise off the Calif or- 

 nian coast at the request of Rear Ad- 

 miral Pond, in order to demonstrate to 

 the Navy what he could accomplish. He 

 sent up in succession Lieutenants Rogers 

 and Charlton to a height of over 400 feet 

 when the cruiser was steaming 20 knots 

 and going through war maneuvers. The 



men aloft were able to sight vessels 40 

 miles away. Submarines operating in the 

 vicinity of the cruiser were easily de- 

 tected, especially when the Pennsylvania 

 was "on soundings," that is to say, in 

 water 50 to 60 fathoms deep. When ob- 

 servers at the masthead were unable to 

 see anything, the men carried up by the 

 kites could distinctly observe the sub- 

 marines at a distance of a mile or so from 

 the ship. Even in the open sea, when 

 traveling between San Francisco and Los 

 Angeles, they could pick out the subma- 

 rines with but little less difficulty. 



The experiments mentioned prove that 

 a merchant vessel which has a speed of 

 12 to 15 knots is able to carry a string 

 of kites and send them aloft with a sailor 

 in a bo'sun chair in order to secure ample 

 protection against submarines. The kites 

 are available at practically all times. 

 Rain does not affect the kites, and when 

 there is a gale that no aeroplane could 

 live in they can be sent aloft quite read- 

 ily, and then possess the added advan- 

 tage of being able to carry two light 

 observers instead of but one. 



RUNNING A STREAM BENEATH A 

 STREAM 



An engineer in the western part of 

 this country was up against the proposi- 

 tion some time 

 ago of making a 

 stream cross a 

 stream, and in 

 order that this 

 might be done 

 he built above 

 the main stream 

 a concrete bridge 

 or trough 

 through which 

 stream No. 2 

 might pass. In 

 a word the sit- 

 uation was like 

 this: An i r- 

 rigating canal 

 twelve feet wide 



and four feet deep ran through a certain 

 stretch of country. Running at right an- 



A Concrete Bridge that Serves to 

 Stream Above Another. 



gles to this ditch are a number of nat- 

 ural storm drains. It was desired that 

 the water from these storm drains should 

 not empty into the main ditch and to 

 avoid this these bridges were construct- 

 ed. The water 

 in the main ditch 

 is used to irri- 

 g a t e valuable 

 orchard land, 

 while that from 

 the various 

 washes goes di- 

 rect to a near- 

 by river. 



The bridge 

 shown in the 

 accompanying 

 illustration is 

 fifteen feet in 

 width and sixty 

 feet long. Its 

 walls are eight 



inches thick and forty-two inches in 

 height. The sides and floors of this 



