Tapping a Subterranean Heat.

Star (Christchurch), Issue 4546, 18 November 1882, Page 3

Tapping a Subterranean Heat.

Several schemes have been proposed for utilising the internal heat of the earth ; and seeing that, as we descend, the temperature increases at the rate of about one degree Fahrenheit for every 68ft or thereabout (this rate varies greatly at different places), the possibility of doing so is evident enough. The praotical question is, whether it is oheaper to bring this into our houies from under our feet, or obtain our supply by disinterring and liberating the fosßil sunbeams entombed in deposits of ooal. What I have read, remarks a writer in the " Gentleman's Magazine," concerning these projeots leads me to the conclusion that the oost of sinking deep enough to boil water, and then to convey the steam, or otherwise the direotly heated air, to our houses, will cosfe far more than the tame amount of heat from ooal ; but as our thickest, best, and moit accessible coal seams prooeed further towards exhaustion, and ooal becomes consequently much dearer, the case may be different. The Americans generally taka the lead in these very tall and extremely nevel schemes, but in this particular effort they are likely to be forestalled by the Japanese, who are seriously contemplating the availability of the hot springs around Tokio as a source of heat and power, and also of using the heat obtainable by sinking. The subjeot was introduced at a meeting of the Beismological Society of Japan— a society which, in its own department (earthquake study), is doing good scientific servioe. Mr Milne, who read the paper, proposes to convert some of the heat into an eleotrio current, and transmit the energy to the town. This, in a region where the hot springs and earthquake disturbances indicate a muoh more rapid increase of heat than that above named,' is of course more likely to be within praotical reach. Besides this, the tapping of subterranean heat in districts liable to earthquakes will probably have some slight effect in moderating these convulsions.