55 c THE POPULAR SCIENCE MONTHLY. 



the serpent, it certainly receives only blood that has previously been 

 aarated; hence we find in this animal no true aerial respiration alter- 

 nating with strictly aquatic respiration. 



But, though the Amia is not amphibious, and hence not to be con- 

 sidered in this place, nevertheless we must not omit to mention the 

 fact that, while at present the genus is restricted within rather narrow 

 geographical limits, it appears to have existed in Europe during the 

 epoch known to geologists as the Middle Tertiary. 



Thus there have been found at Oeningen (Switzerland), Kutschlin 

 (Bohemia), Menat and Armissan (France), fossil remains of Cyclurus, 

 which has a close affinity with Amia. It is highly probable, not to 

 say certain, that these tishes buried themselves in the mud during the 

 dry season. The little tertiary lakes of Limagne appear to have 

 undergone in past times alternations of drought and humidity, like 

 the marshes of tropical and inter-tropical countries. 



The presence in Europe of a genus closely allied to the Amia of 

 America would seem to show that, at a relatively late period, these 

 two divisions of the world were connected. The study of tertiary 

 insects, to which E. Oustalet has devoted himself, and a thorough 

 investigation of fossil fishes, would, we think, tend greatly to confirm 

 Oswald Heer's hypothesis, according to which an Atlantis not an 

 historical Atlantis, as understood by Plato, but a geological Atlantis 

 connected the north of Europe with America toward the close of 

 the great Tertiary epoch. 



INDUSTRIAL APPLICATIONS OF SOLAR HEAT. 1 



Br L. SIMONIN. 



THE history of burning-mirrors of brass is known. At Rome the 

 sacred fire was lighted with apparatus of this kind, and Archi- 

 medes fired the ships which were blockading Syracuse by concentrat- 

 ing upon them the sun's rays by means of a large reflector. Bufibn 

 repeated successfully the experiments of Archimedes. With a mirror 

 of very slight curvature, consisting of a number of pieces of looking- 

 glass, he set fire, at some distance, to fir and beech planks, melted tin 

 and silver, and brought iron to a red heat. Saussure later accumu- 

 lated, by means of superimposed inclosures of glass, the sun's heat up 

 to a temperature exceeding that of boiling w T ater, and Sir John Her- 

 schel repeated these experiments at the Cape of Good Hope at various 

 times between 1834 and 1838. At the same period the French physi- 

 cist Pouillet was engaged at Paris in measuring the calorific intensity 

 of solar radiation, arriving at the conclusion that the heat emitted 



1 Translated from the French, by J. Fitzgerald, A. M. 



