(i3() 



Popular Science Mcndhly 



Employing Kites to Support 

 an Aerial 



A DOZEN yciirs ago there occurred to 

 Army officers the idea of sending 

 up a wireless aerial to a great height by 

 means of kites, in order to increase the 

 sending and receiving range of a field 

 radio set. A few experiments were 

 made, but without great success. In 

 1908 further attempts were made in this 

 line, but again without especially en- 

 couraging results. 



After the German steamship, Prinz 

 Eitel I-Viedrich, had been interned at 

 Norfolk, Va., last spring, a story leaked 

 out as to how her captain (Herr Thierich- 



6'/tx^a' l//ie 



Manner of keeping aloft aerials with a string 

 of kites on a line of unvarying length 



sen) kept posted as to the wiiereabouts 

 of enemy ships, and was thus able to 

 avoid them for many months. lie 

 adopted the simi)le expedient of sentling 

 aloft an aerial sup[)orted by a string of 

 kites. Such excellent results were ob- 

 tained that a paper containing wireless 

 news of the war was prinli'd daily on 

 board shi(). 



i<e( ailing this use of kiti's by thetier- 

 man ship, ,\djulanl (ieneral Cole, of 

 the Massachusetts V'olunli'ir Militia, 

 decided to resume ex|)eriments with a 

 kite-supported aerial. C'onsc(|uently lie 

 in\'ilcd Sainne! !•". I'erkins, of Hoston, 



make some further tests at tiie July 

 maneuvers of the Militia in northeastern 

 Massachusetts. Late one afternoon, at 

 Newbury, Mr. Perkins sent up four of 

 his huge hexagon kites. The aerial was 

 attached to the kite line about half way 

 between the kites and the earth, and 

 hung vertically a distance of about 600 ft. 

 to the ground. The lower end Avas 

 attached to an ordinary >:»-k. w. field 

 radio set, such as is used ordinarily with 

 a 25 or 30-ft aerial. The swaying up 

 and down of the kites caused the end of 

 the aerial to be jerked off the earth or 

 to coil up upon it, and consequently the 

 operator was unable to tunc, because of 

 the constantly varying length of the 

 aerial. He explained to Mr. Perkins 

 that this was the cause of failure in 

 many earlier kite experiments. With 

 Yankee ingenuity Mr. Perkins soon put 

 an end to the varying in length of the 

 wire, and from that moment almost 

 startling results were obtained. 



The method by which the aerial was 

 kept at an unvarying length is illustrated 

 in the diagram, where ,4, B and C 

 represent the kite line in three different 

 positions corresponding to the verticals 

 D, D\, and D2. A shows the lowest and 

 C the highest positions of the constantly 

 swaying kites. By securing tlie vertical 

 aerial wire to the ground when the kite 

 line has reached its lowest angle, any 

 fuither rise of the line occurs from the 

 point D at the toj) of the aerial instead 

 of from the point where the kite line is 

 secured to the ground. Consequently, 

 the point D always remains at a given 

 height and the length of the aerial is 

 always the same. It was this simple idea 

 of holding down the kite line by means 

 of tile aerial itself that made the ditfer- 

 ence between success and failure, and 

 made it possible to increase the range of 

 an ordinary ,'4-k. w. wireless set so 

 greatly that it became in many ways 

 the etiual of a big tractor-.sct worth 

 thousands of dollars. 



As soon as the aerial was kepi at an 

 uinarying length in (he experiment men- 

 tioned above, messages were received 

 from the I'ilene Station at Boston, from 

 the Battleshi)) Georgia olT Newport, 

 from .Arlington, Va., and even from as 

 far away as Bermuda, a distance of over 

 a thous.ind miles. 



