KITE-FLYING IN 1897. 53 



kites over a pulley, which turns so as to deliver it 111 any <1ireetiori 

 to them. There is also a wheel which records tlie pull of the line, 

 and a provision for recording the nieasuremenr of length. Thus 

 the relation of wind pressure to pull, and several other matters, can 

 at any minute be figured out. 



The purpose of the observatory from the first was to secure by 

 means of kites a more elevated plane of observation than could be 

 obtained by other means. As soon as the corps had acquired skill 

 in kite making and flying, a self-registering thermometer was sent 

 up; afterward they were able also to add a barometer, these being 

 carried on a base, covered by a wire basket, and attached to the line 

 as high among the kites as it could be sustained. 



But the two instruments did not furnish a record of all the ele- 

 ments; and finally a complete "meteorograph" was devised. Ex- 

 ternally, this was a cage of wire one foot in height, the same in 

 width, and half that in the other dimension. The weight of a simi- 

 lar one used in Washington is two pounds and a half. The com- 

 bination wathin consists of a thermometer, barometer, hygrometer, 

 and anemometer — all making record on a sheet of paper wound on 

 a cylinder that is revolved by clockw^ork. As the direction of the 

 wind is ascertained by the drift of the kites, each flight furnishes 

 the observers with five meteorological elements. No doubt they 

 will be able ere long to determine the electrical conditions at differ- 

 ent heights with equal accuracy. 



Every well-constructed kite has a fixed capacity for ascending 

 to a certain height — not more than a few hundred feet usually, be- 

 cause of the increase in the weight of the line and the wind's pres- 

 sure on it; therefore, in order to reach a greater altitude, it became 

 necessary to connect another kite to aid in the lifting. Still higher 

 flights required a further addition of kites, until sometimes a dozen, 

 ranging in size from five to twelve feet, were up in the same tandem, 

 requiring a small rope to hold them. A large and divided wind 

 surface was necessary, else in lulls the kites would descend and the 

 instruments with them; so the obtaining of observations was at great 

 cost of time, labor, and money. In a fresh w^ind the vigorous 

 efforts of three strong men were required for two or three hours to 

 bring a large tandem down. Several times, in strong winds, the 

 kites have broken away, only reaching the ground two, four, and 

 nearly six miles distant; yet nearly every time they have been re- 

 covered without having sustained much damage. 



For the reason mentioned on a previous page, some two years 

 since, No. 14 steel music wire (the size of small piano strings) w^as 

 substituted for the line of vegetable fiber. A mile of this wire 

 weighs from twelve to fifteen pounds, which is much lighter than 



