FOR HIGH LEVELS IN THE EARTH's ATMOSPHERE. 73 



These times of passage through the level surfaces as given in columns 21 and 23 

 may readily be obtained graphically as follows : The times given in column 1 are 

 plotted as abscissae and the values of V in column 9 as ordinates. Then the 

 (Time, F)-curve is drawn through the points thus plotted and from this curve the 

 time of the moment of intersection for each 10 000th level surface of gravity may be 

 I'ead off directly. 

 Nos. 22 and 24 give the values of tr at each passage through the level surfaces of 



column 20 ; these values having been read from the curves for the kite ascension 



shown in Fig. 2. 



Preparation of Synoptical Charts at the Central Station. 



For synoptic study at the central station it is sufficient to telegraph only some of 

 the most important of the quantities above calculated, e.g., the quantities n^""", n^oooo, 

 n'fo Z, V,-,,s, Elfl, and Eig. The value of Uf «"> is obtained by subtracting ji^^ ooo = 27.087 

 from the reading of the station-barometer reduced to sealevel, or jjo = 29.74, whence 

 results the difference, no""" = 2.653. In the same way are obtained the values 

 Uf,Z = 27.087 - 24.651 = 2.436, and W^Z = 24.651 - 22.409 = 2.242. The value 

 of F27.6 = 33 550 is taken directly from column 18 of Table 15. The values of 

 E^i = 40 470, and Egg = 44 230 are the differences V^^.o- V,,,^ and V22.5- V^,o respec- 

 tively. The numbers to be telegraphed to the central station are therefore 2.653, 

 2.436, 2.242, 33 550, 40 470 and 44 230. For telegraphic purposes these numbers 

 may be shortened by dropping the first and the last figures of each, so that we have 

 to telegraph only the abbreviated numbers 65, 44, 24, 355, 047 and 423. These may 

 be combined into three groups of five figures each, as for example 65 355, 44 047, 

 24 423.* 



Now assume that all the kite-stations where ascensions were made with register- 

 ing instruments during the forenoon of 23 Sept., 1898, had worked up their obser- 

 vations according to the foregoing method and sent telegraphic reports to the central 

 office. Then these telegrams as received would have read somewhat as follows : 



23 Sept., 1898, 8 A. M., 75th Meridian Time. 



Cleveland, O. 68 135 48 963 



Dodge City, Kan. 74 193 44 016 22 446 



Knoxville, Tenn. 70 635 49 993 



Omaha, Nebr. 65 355 44 047 24 423 



Pierre, S. D. 73 076 410.54 



Topeka, Kan. 68 363 43 074 



* This contraction for economy in European telegraphy would he advantageously replaced in America hy our usage of 

 short cipher code words or syllahles. — C. A. 



