92 ANNUAL OF SCIENTIFIC DISCOVERT. 



hourly advance of a solar ray which had penetrated his laboratory. He 

 immediately conceived the idea of applying this fact to the electric tele- 

 graph and other purposes, and states that he is now engaged in vigor- 

 ous experiments, with the view of arriving at the exact numbers which 

 establish the advantages which may be derived from the phenomena. 



Magnetism, Electricity, and Vegetation. In his Physique du Globe, 

 M. Quetelet tells us that on examining attentively the value of the 

 monthly magnetic variation, it is found to be in direct relation with the 

 force of vegetation. When the latter sleeps, which happens in the 

 months of November, December, January, and February, the magnetic, 

 variation, at Brussels, is almost uniformly 5' 28", or scarcely half during 

 the period of its full activity, that is to say, from April to September, 

 when its mean is 10' 15". It reaches its plenitude in April, when the 

 mean is 11' 14", for Brussels. In another passage, M. Quetelet states, 

 that the electricity of the air is intimately connected with the action of 

 vegetation, and that the two phenomena have a nearly parallel march. 

 It is not pretended that one depends on the other, but that both arise 

 from the same cause. The quantity of atmospheric electricity at noon 

 is much greater in winter than in summer, the relation being about 10 

 to 1. This augmentation of electric force proceeds in a manner almost 

 parallel with the number of days of frost and fog, and inversely as the 

 number of days of thunder, of elevation of temperature, of actinic power. 



Terrestrial Magnetism and Temperature. At a recent meeting of 

 the Royal Society, the Astronomer Royal mentioned that the remark- 

 able change which had taken place in the phenomena of terrestrial 

 magnetism, as observed at Greenwich since 1845, was such as might be 

 expected to take place, were the climate of the northern hemisphere 

 to become more wintry in its character, while that of the southern 

 hemisphere remained unaltered. It is already on record that Sir John 

 Herschel considers the climate of the earth to be undergoing a change 

 due to some cosmical cause. Is there any connection between his con- 

 clusions and those of the Astronomer Royal ? To those who take in- 

 terest in the progress of terrestrial magnetism as a science, it will be 

 gratifying to know that Mr. Airy expresses himself decidedly in favor 

 of long-continued simultaneous observations in various parts of the 

 globe. With series of observations extending over many years it be- 

 comes possible to institute comparisons, to note fluctuations and disturb- 

 ances, and to discover something of their laws ; while short and broken 

 series baffle investigation, and harass the inquirer to no useful purpose. 

 London Athenceum. 



Sun-spots and Auroras. The Comptes Rendus contains a letter 

 from M. R. Wolf to M. Remmont, in which the former says, " I find, in 

 accordance with M. Fritz, that the frequency of solar spots corresponds 

 exactly with that of auroras, so that we observe in the latter both the 

 period of 11-1- years and the great period of 56 years, the existence of 

 which I have demonstrated for solar spots." 



Thunderstorms and the Moon. M. Bernardin calls the attention of 

 the Belgian Academy to the fact that many thunderstorms have oc- 

 curred about the period of the new or full moon, and he invites inquiry 

 for the purpose of ascertaining whether there is any connection between 

 the movements of our satellite and the electrical condition of the at- 

 mosphere. 



