FOREIGN CORRESPONDENCE 649 



a very violent current ; at 250 yards higher the atmosphere was perfectly 

 calm. This rapid stratum of air between two motionless layers is a rare cir- 

 cumstance. At the altitude of 1,200 yards the temperature was only 53° 

 Fahrenheit, while the sun's rays were scorching. At 880 yards the atmos- 

 phere was full of "virgin's threads," which are only agglomerations of 

 spider's threads, thus attesting how solar heat, or atmospheric movements, 

 can whirl up light substances. 



M. Breguet has brought the telephone, or speaking telegraph, under the 

 notice of the Aca,demy. The apparatus is simplicity itself — a small circular 

 plate of thin metal, vibrating in presence of a magnetic bar ; by means of a 

 little bobbin of fine metallic thread, on the extremity of the bar, are com- 

 municated these currents of vibration to an identical apparatus situated at a 

 distance more or less great. The French savants rather appeared to forget 

 that the most extraordinary fact about the discovery is the value of the idea 

 — that sound can be telegraphed distinctly, thus opening up a world of in- 

 dustrial applications. Hardly have the conducting powers of tubing being 

 employed for speaking directly between two houses, or throughout vast 

 buildings, when the telegraphe parlant is announced to supercede it, M. 

 Breguet stated that not the least astonishing property of the marvelous new 

 invention is, that of all telegraphs known, it functions under the influence 

 of the most feeble currents. Further, he announced that after interlacing 

 the sound in a resistance equal to a distance of 1,000 kilometres of ordinary 

 telegraphic wire, he was able to hear phrases most distinctly, that is to say 

 625 miles. The apparatus collects, transmits and receives the sound of the 

 voice. What a field is here opened for the imagination ! Communications 

 exchanged, irrespective of distance, with the living and personal character 

 of yoice, instead of the cold written representation of thought. The first 

 metal disc indirectly produces the currents, and the latter develops, also 

 indirectly, the vibrations in the second disc. It has been objected that the 

 second plate in vibrating symmetrically, while emitting the same sound, 

 does not produce the same volume. The currents are thus modified in their 

 course. This may explain why the tone of the voice has failed to be "wired." 

 Tone is but the superposition of a certain number of sounds upon a funda- 

 mental sound ; a kind of very complicated mixture. The sound " received," 

 as compared with that "dispatched," was alleged by some academicians, as 

 a painted photograph of a painting to the painting itself. The results may 

 be different when Mr. }3ell conducts the experiments. The discovery with 

 all its imperfections is not the less astonishing. What progress since the 

 celebrated "ear" of Dionysius of Syracuse? 



M. Rodier draws 'attention to the fact that submerged aquatic plants 

 have the property of spontaneous movejpent. In June last he watched this 

 rotation, which attained to 45 degrees. During the night the same plants 

 turned in an inverse direction. M. Cornu has'^conducted some experiments 



