Rensselaer Gazette, Volume 3, Number 18, Rensselaer, Jasper County, 24 August 1859 — The Interior of the Earth. [ARTICLE]

The Interior of the Earth.

There are m :ny circumstances which induce the belief that the interior of the earth has a much higher temperature than its sur-,r face. Thus, experiments show that mineral substances may be made to assume a crystalline form when cooled from a state of fusion; and this result, connected with other facts, prove that many of the crystalline rocks were produced by the agency of fire. The existence of more than two hundred active volcanoes affords evidence that there is an intense internal heat; and the agency of fire in the production of some rocks, and in modifying, if not in producing, the present state of the earth’s crust, is now generally admitted. The increase of temperature niso appears to be according to The depth from the surface of the earth. The increase of the subterranean heat in proportion to the depth, does not, however, follow the same law in all places. From experiments made beneath the Observatory of Paris, it was deduced that at that place a depth of fifty-one feet corresponds with an increase of one degree of heat, from which it would follow, admitting a similar continued increase, that the temperature of rocks at a depth, under the city of Paris, of about a mile and a half is equal to that of boiling Lot it be admitted then that the increase or temperature is about one degree for every fiften yards of descent—though it will probably be found to be in a geometrical progression cs investigation extends—water will boil at the depth of two thousand four hundred and thirty yards; lead melts at the depth of eight thousand to r hundred yards; there is red heat at the depth of seven miles; gold melts at twenty-one miles, cast iron at eeventvfou{r miles, soft iron at ninety-seven miles; and at the depth of one hundred miles there is a temperature equal to the greatest artificial heat yet observed—capable of fusing platina, procelainj and indeed every refractory substance known.