408 Intelligence and Miscellaneous Articles, 



the sunrise and sunset on the sea; for, from the purity of the Ionian 

 sky, sharp pictures were to be expected even on the horizon. 



In fact I succeeded in observing, and often in the most surprising 

 manner, the phenomenon of condensation, especially of the lines in 

 the red and yellow of the spectrum, which I had seen in our latitudes, 

 although much more dimly. I also observed the increase in the 

 number of the lines at the setting of the sun. A single glance into 

 the spectroscope was enough to convince even non-scientific specta- 

 tors, and hence to remove any doubt as to a possible subjective 

 perception. I have repeated these observations not only on the 

 sea, but also on the continent, in Athens, in Zante, Cerigo, and 

 Ithaca ; and although no measurements could be made, the phe- 

 nomena were so marked, that, from the relative position of the 

 spectral lines, I can almost guarantee in this case a one-sided con- 

 densation towards the violet end, just as I have shown it in the case 

 of hyponitrous acid and chlorophyll*. 



For spectrum observations, Greece, and especially the Ionian Islands, 

 are most suitable stations ; for the dense layers of vapour observed 

 almost every day on the coasts of Africa and America, there scarcely 

 disturb the observer. — PoggendorfF's Annalen, May 1862. 



MODE OF APPLYING THE ELECTRIC LIGHT FOR MINING PURPOSES. 



BY MM. DIJMAS AND BENOIT. 



The apparatus consists essentially of three parts — a battery, a 

 Ruhmkorff's coil, and a Geissler's tube — the whole arranged so as 

 to produce a sufficient light to illuminate the miner, and allow him 

 to work in atmospheres where other lights fail. 



The light produced is cold, or rather does not heat the tube in 

 which it is produced ; and gas has no access to it : it is quite iso- 

 lated. The apparatus is as compact as ordinary lamps, and there 

 is no injurious emanation. It can be lighted or extinguished at will. 

 It can work for twelve consecutive hours without diminution, and 

 without requiring any change. The workman has only occasion- 

 ally to agitate the carbon by means of a rod. 



The greatest difficulty consisted in being able to associate a bat- 

 tery of such intensity that the weight of the apparatus was as small 

 as possible, the light produced of the greatest regularity, and its 

 duration at least twelve hours. The present form of the apparatus, 

 which may be still further diminished, is already so small that the 

 miner can carry it without inconvenience, like a small carpel, bag. 



The authors point out the advantages of such a mode of illumina- 

 tion, and state that the results obtained in using Becquerel's fluor- 

 escence-tubes have led to the expectation that the luminous effects 

 may be greatly improved both as to duration and intensity. — Comptes 

 Rendus, September 8, 18C2. 



* Phil. Mag. vol. xxii. p. 80. 





