Apbil 27, 1906.] 



SCIENCE. 



673 



the mountain. This valley is open toward 

 the west, whence come the prevailing winds, 

 and there are ample open spaces suitable for 

 kite flying. 



The meteorological data were obtained from 

 four meteorographs constructed as nearly alike 

 as possible in order to secure uniform action, 

 all having the same scales and each recording 

 the temperature, atmospheric pressure, hu- 

 midity and velocity of the wind upon a paper- 

 covered cylinder rotated once in twelve hours 

 by a clock. The time-scale was about 25 milli- 

 meters an hour and data could be obtained 

 every two minutes. Two of these instruments 

 were employed in recording the conditions on 

 the summit of Mount Washington and at the 

 kite station near Twin Mountain, and two 

 were adapted for use in the kite experiments, 

 being a modified form of the kite meteorograph 

 devised by me for use at the Blue Hill Ob- 

 servatory. All of the instruments were care- 

 fully compared with standards. 



The meteorograph on the summit of the 

 mountain was exposed in the north window 

 of the office of the newspaper Among the 

 Clouds, the editor, Mr. Prank H. Burt, very 

 kindly volunteering to keep it in operation 

 during the experiment. The exposure, so far 

 as temperature, humidity and pressure are 

 concerned, was very good. The anemometer, 

 which recorded electrically, was placed on the 

 roof of the office near the western end and was 

 well exposed to the winds from all directions 

 except those between northeast and southeast, 

 which were obstructed by the other buildings 

 on the summit. 



The kites employed were two Eddy kites 

 respectively of 1.67 and 3.20 square meters 

 area, and two 'Blue Hill box' kites, each 

 having a lifting surface of 2.0 square meters. 

 A ' hand ' windlass containing 3,400 meters of 

 No. 11 music wire, and provided with accurate 

 devices for indicating the length of line em- 

 ployed and for recording the pull of the kites, 

 was employed in flying the kites. The 

 heights reached were chiefly determined from 

 altitudes obtained by means of a transit, 

 though intermediate heights could be obtained 

 from the record of atmospheric pressure. 



It was intended to keep one of the kite 

 meteorographs as nearly as possible at the 

 same height as the summit of Mount Wash- 

 ington, and the other about half as high, and 

 in this way obtain a vertical section of about 

 1,500 meters; the Twin Mountain station be- 

 ing 427 meters and the summit 1,916 meters 

 above sea level. 



The instruments at the summit and kite 

 stations were compared with a standard ther- 

 mometer three times each day and comparisons 

 of the kite meteorographs were made at the 

 beginning and end of each flight. 



After the apparatus was installed there re- 

 mained but five days for the actual work of 

 observation, and to my surprise, the wind was 

 so exceedingly light throughout the entire 

 period that but two flights could be obtained; 

 during one of which, however, the upper 

 meteorograph was carried to within 60 meters 

 of the height of Mount Washington. An ac- 

 cident to one of the kites prevented more than 

 one observation at this height; but since this 

 appears to be the first time such observations 

 have been made so near a mountain observa- 

 tory, it may be worth while giving the results 

 in detail. 



AUGUST 24, 1905. 



At 5 :44 P.M. one of the two supporting kites 

 collapsed and the other, not being sufficient to 

 support the meteorograph and line until they 

 were reeled in, fell into the forest on the north 

 slope of the ' Three Sugar Loaves ' (a small 

 mountain 300 meters higher than the kite 

 station) and the flight came to an abrupt end. 



