THE EARTH’S HEAT.

Hawera Star, Volume XLVIII, 27 October 1924, Page 6

THE EARTH’S HEAT.

There in nothing new in the recent suggestion of the. possibility of using the earth’s heat to „ produce poAver, writes T. C. Bridges in the Daily Mail. More than twenty years ago the official geologist for the State of Pennsytoania (U.S.A.) propounded a serious engineering scheme for utilising the internal heat of the earth. He proposed to make bore-holes deep enough to reach the layer,of high temperature,, about five miles doAvn, to- admit of cold AA’ater to these, and to utilise for motive poAA’er the hot Avater and high-pressure steam which wo-uld be produced*. Such a bore would have to- be a double one, and at present the mechanical difficulties of boring to such a depth stand in the Avay of this suggestion. In any case, the expense would be enormous. There are, hoAA’eA'-er, many places Avhere the underground fires can be tapped Avithout the use of any drilling machinery, and there is one where this has act-ually-been done, and where poAver is to-day being obtained in this manner at a very cheap rate. The site of this experiment is Larderello, in Italy, about 40. miles southAvest of Florence. At Larderello is an area of more than tAvo square miles, where jets of steam and boiling springs burst up in scores. About tAA’-eb’-e vears ago it occurred to a certain Italian nobleman that here was power going to Avaste He was Prince Conti, and he set to Avork to erect an electric generator to be driven by steam from one of tlie natural jets. The experiment proved a success, new machinery has been added, and to-day a heavy head or electric power runs several factories near the spot, while the surplus current is used for lighting Florence as Avell as Siena and other toAvns.