USE OF KITES IN METEOROLOGICAL OBSERVATIONS. 225 



tailli\ss kite resembling- the one used in Java, except that the horizontal 

 cro.s.spiece is nearer the toj) of the vertical stick, and its ends are bent 

 backward in a lx>w and connected by a cord. The next year, with 

 several of these kites Hown tandem, he lifted a minimum thermometer 

 and proposed to obtain in this way data to forecast the weather. 



Up to this time it does not appear that self-recording instruments — 

 that is to say, those which make continuous graphic records — had 

 been raised by kites. In the days of the early experimenters such 

 instruments were too heavy and cumbersome to be lifted b\^ the more 

 or less unmanageable kites, but within the past few years M. Richard, 

 of Paris, has made recording instruments sufficiently simple and light 

 to be attached to kites. In this way it is possible to obtain simulta- 

 neous records at the kite and at a station on the ground, and from them 

 to study the differences of temperature and humidity, and this seems 

 to have been done first at Blue Hill Observatory. In August, 1894, 

 Mr. Eddy brought his kites to Blue Hill, and wdth them lifted a Rich- 

 ard thermograph which had l)een partly reconstructed of aluminum 

 by Mr. Fergusson, of the observator}^ so that it weighed but 2i 

 pounds, to the height of 1.400 feet, and here the earliest automatic 

 record of temperature was obtained by a kite. During the next sum- 

 mer Mr. Edd}^ secured photographs of the observatory and hill by a 

 camera carried between his kites to the height of a hundred feet or more. 

 Now, that the possibility of lifting self-recording meteorological instru- 

 ments to considerable heights had been demonstrated, an investigation 

 of the thermal and hygrometric conditions of the free air was under- 

 taken by the staff of the Blue Hill Observatory, who had already made 

 an investigation of the currents of air at various heights b}'^ measure- 

 ments of the clouds. 



In the early experiments the Eddy, or Malay kites, as they are also 

 called, covered with paper or wdth varnished cloth and coupled tandem 

 to secure greater safety and lifting power, were used. The kites were 

 attached at several points on the line, for although it can be demon- 

 strated theoretically that a greater height is possible by concentrating 

 all the pull at the end of the line, yet in the actual case of a line which 

 is not infinitely strong the best results are got by distributing the pull, 

 and in this way, too, kites can be added as the wind conditions aloft 

 permit. The Eddy kite flew at a high angle above the horizon alnd 

 through a considerable range of wind velocity, but it could not be 

 kept permanently in balance or made to adjust itself to great varia- 

 tions in wind velocity, and therefore it was discarded. 



The first meteorograph. ))eing a combined recording thermometer 

 and barometer (from which the height can be obtained), was con- 

 structed by Mr. Fergusson in August, 1895, and three months hiter he 



