THE EARTH’S HEAT.

Ashburton Guardian, Volume I, Issue 21, 13 November 1879, Page 4

THE EARTH’S HEAT.

To tub Editor. Sib, —In your issue of the 30th Oct., a correspondent disposes of the thermometrical observations taken by the manager of the Magdala Mine, Victoria, in a very summary manner. He seems also to assume that your judgment was at fault in allowing the article he refers to, to appear in the columns of your paper ; and concludes with thinking you ought to be pleased with having it corrected. Now, however, unorthodox it may appear to Mr Westbrooke, I for one believe that the manager of the mine in question is pretty nearly correct, and as there can be found on the goldfields of Victoria as clever experts, and as correct instruments, as elsewhere in the world, the matter can very easily be put at rest. lam about to write to the manager of the Magdala Mine on the subject, and I know that if he is likely to encounter any difficulties in his thermal investigations, the Minister of Mines for the Colony will—in the interest of science—be delighted to afford the Tiacewafliy moans to have the question seftle3^eyon3lsavn.

Perhaps Mr Westbrooke will have to admit that our scientific knowledge always has, and will yet continue to, require modification from time to time. If the heat of the earth increased—as a good many learned men have affirmed, at the rate of 100° per mile as we descend towards its centre, what condition would the bottom of the ocean be in at the depth of 6 or 7 miles ? I would imagine that it would resemble the bottom of ■ water in a frying pan over a great fire ; and the consequent oceanic disturbance arising therefrom would bring about whirlpools and currents, compared with which the Gulf Stream would he but an . infant. In place, however, of such disturbance existing at great depths, the observations, of Commander Maur’y, of the. United States Navy, and of the officers of her Majesty’s ship Challenger, fully establish the very opposite condition of things. Mr Westbrooke will, I think, see that he himself is rather misleading where ne says that at 100 ft from the surface we find the mean temperature of the earth. The depth of meen temperature varies with the latitude, though not in a very uniform manner ; following in a measure, but inversely, the isothermal lines. At Stawell, Victoria, it will, I believe, be found somewhere about 40ft from the surface. Ido not for a moment doubt the accuracy of the recorded heat of European mines ; but I have the strongest doubts as to the uniformity of that heat at the same level all the world ever.

I will conclude with assuring you that all articles appearing in your valuable paper, bearing on recent scientific discoveries, will be read with much pleasure by many of your subscribers, whether such discoveries have had time to receive the unerring si amp of mathematics on the face of them or not. 1 am, sir, Your obedient servant, *|~) OIiIVBR Westerfield, Nov. 10th, 1879.