RADIO ATMOSPHERIC DISTURBANCES—AUSTIN 205 
charges of thunderclouds to the upper conducting region of the 
atmosphere. His calculations indicated that thunderclouds of com- 
mon electric moment might very readily discharge to a conducting 
layer at a height of 60 or 80 kilometers, since the electric force 
required to produce discharge decreases even more rapidly with the 
height than the electric force of the thundercloud. Discharges of 
this kind, probably nonluminous, may possibly furnish the explana- 
tion of the strong atmospherics heard from thunderclouds when no 
flashes are visible. 
Mr. Watson Watt, in analyzing the records of European * direc- 
tion-finding stations, concluded that in only about 35 per cent of 
r-- 
Ss 
ise Sec, cmap 
(4) (5) 
Fies. 1, 2, 3, 4, and 5.—Atmospheric disturbance curves observed by Appleton and Watt 
the cases could thunderstorms be identified as the sources of atmos- 
pheric disturbances, though in about 75 per cent of the cases the 
indentified sources were rain areas of some kind. 
Captain Bureau * of the French Meteorological Office has recently 
published papers in which he shows that many of the atmospheric 
disturbances in France are closely connected with the advance of 
meteorological cold fronts and that the atmospherics are accentuated 
when these air movements come in contact with mountain ranges. 
For the determination of the direction from which atmospheric 
disturbances come, Mr. Watt ** has invented an automatic recording 
2 Nature, 110: 680. 1922. 
18C-R, Acad. Sci., 176: 556 and 1623. 1924: L’Onde Blectrique, 3: 385. 1924. 
4 Proc. Roy. Soc., A, 102: 460. 1923. Phil. Mag., 45: 1010. 1923. 
