122 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



concomitant features of mountain corrugation ; and in re- 

 'j-ions of such corrusfation we should look for thermal wa- 

 ters. Designating upon a map the localities of the numerous 

 springs reported by Mr. Gilbert, the first thing noted is that 

 the Mississippi Valley contains no hot spring, nor do the 

 plains of the Atlantic coast. Among the Ozark Mountains 

 of Arkansas we have one. In the Colorado Plateau five lo- 

 calities are noticed. The distribution of hot springs is found 

 to coincide very exactly with that of corrugation. The range 

 of temperature of the waters is far higher in the western re- 

 gion than in the eastern. Haydei'Cs Survey and Heports^ 

 1876,145. 



CONNECTION BETWEEN SOLAR SPOTS AND TERRESTRIAL ELEC- 

 TRICITY. 



As the result of his study upon the frequency of thunder 

 and lightning storms in Germany and Switzerland, Von Be- 

 zold concludes it probable that high temperature as Avell as 

 a solar surface free from spots are the conditions bringing 

 about years rich in electrical displays. Since, however, the 

 maxima of solar-spot surface agrees with those of greatest 

 intensity of the auroras, it follows that both kinds of elec- 

 trical phenomena, thunder-storms and auroras, are in a cer- 

 tain manner complementary to each other, so that years rich 

 in thunder-storms are poor in auroras, and vice versa. Such 

 a connection between sun-spots and thunder-storms implies, 

 however, by no means the assumption of a direct electric in- 

 terchange between the earth and the sun, but can rather be 

 considered as a consequence of the variable solar insolation 

 as dependent upon the solar-spot surface. The variations of 

 insolation, according to Koppen, are not felt simultaneously, 

 but rather successively in the various latitudes of the earth. 

 The thunder-storms depend not only upon the temperature 

 of the place of observation, but also upon the condition of 

 the atmosphere at points far distant and belonging to other 

 climatological zones, as is best seen in the thunder-storms 

 accompanying extensive storms. In this way perhaps can 

 best be explained the peculiar position which the curve of 

 thunder-storm frequency holds between the solar-spot curve 

 and the temperature curve. Sitzh. K.-B. Akad. der Wissejis., 

 i)l/2?ic/?, 1874, IV, 318. 



