velocity of one mile in a second, would extricate heat equal to 30,000° of Fahrenheit--a heat more intense than that of the fiercest artificial furnace that ever glowed. The chief modification given to the Chladnian theory has arisen from the observed periodical occurrence of meteoric showers--a brilliant and astonishing exhibition--to some notices of which we proceed. The writers of the middle ages report the occurrence of the stars falling from heaven in resplendent showers among the physical appearances of their time. The experience of modern days establishes the substantial truth of such relations, however once rejected as the inventions of men delighting in the marvelous. Conde, in his history of the dominion of the Arabs, states, referring to the month of October in the year 902 of our era, that on the night of the death of King Ibrahim ben Ahmed, an infinite number of falling stars were seen to spread themselves like rain over the heavens from right to left, and this year was afterward called the year of stars. In some Eastern annals of Cairo, it is related that "In this year (1029 of our era) in the month Redjeb (August) many stars passed, with a great noise, and brilliant light;" and in another place the same document states: "In the year 599, on Saturday night, in the last Moharrem (1202 of our era, and on the 19th of October), the stars appeared like waves upon the sky, toward the east and west; they flew about like grasshoppers, and were dispersed from left to right; this lasted till day-break; the people were alarmed." The researches of the Orientalist, M. Von Hammer, have brought these singular accounts to light. Theophanes, one of the Byzantine historians, records, that in November of the year 472 the sky appeared to be on fire over the city of Constantinople with the coruscations of flying meteors. The chronicles of the West agree with those of the East in reporting such phenomena. A remarkable display was observed on the 4th of April, 1095, both in France and England. The stars seemed, says one, "falling like a shower of rain from heaven upon the earth;" and in another case, a bystander, having noted the spot where an aërolite fell, "cast water upon it, which was raised in steam, with a great noise of boiling." The chronicle of Rheims describes the appearance, as if all the stars in heaven were driven like dust before the wind. "By the reporte of the common people, in this kynge's time (William Rufus)," says Rastel, "divers great wonders were sene--and therefore the king was told by divers of his familiars, that God was not content with his lyvyng, but he was so wilful and proude of minde, that he regarded little their saying." There can be no hesitation now in giving credence to such narrations as these, since similar facts have passed under the notice of the present generation.