Correspondence — Rev. W. Doivnes — Mr. J. J. Murphy. 525 



ColcTaester), and a list of 314 works on the Geology and Palee- 

 ontology of Suffolk, together with an Index, complete the volume. 



On the whole this Memoir, like most of those issued of late years 

 by the Geological Survey, contains a large amount of dry detailed 

 description, far from attractive to an " ordinary reader," and not at 

 all calculated to ai'ouse enthusiasm in the science. And yet these 

 details may prove of great service in many ways, both practical and 

 scientific. We are, however, informed by the Director-General in 

 his prefatory notice to this Memoir, that the whole of the Pliocene 

 deposits of the East of England having now been completely sur- 

 veyed and published, it is intended to prepare a Stratigraphical 

 Monograph illustrative of them. This we presume will bring out, 

 more clearly thaa could otherwise be the case, the general results of 

 the official and other woi'k, towards the elucidation of which the 

 Memoirs explanatory of particular maps will furnish a solid, if not 

 very entertaining, basis. 



C OK/DBIB S IPO IsT JDIE InTC IB . 



UNDERGROUND HEAT. 

 Sir, — It was with much interest that I read in the September number 

 Mr. J. S. Gardner's article upon the above subject, and the more so 

 as it is rather a pet subject of my own. Though I have never suc- 

 ceeded in throwing so much practical light upon it as Mr. Gardner 

 has, I ventured in an article in Belgravia as long ago as June, 1881, 

 to forecast that the day might come when we might see " conductors 

 of subterranean heat ramifying like the gas pipes of a city into every 

 house, and superseding the use of fuel." But I never, until now, 

 found any one willing to treat the subject otherwise than as 

 wild and visionary. With, however, the astonishing inventions and 

 developments of machinery which every year presents to us, it 

 would be nothing strange if a means were found of getting at this 

 pi'actically exhaustless snpply of heat long before the finite quantity 

 represented by our fuel reaches the beginning of its end. At a 

 measurable distance beneath us we have hot air and hot watei'. 

 Geysers, Mr. Gardner tells us, have actually been utilized for heating 

 purposes. To make a geyser at a given spot would be only a 

 question of money and skill, often probably not a greater under- 

 taking than laying down an Atlantic cable ; and the one undertaking 

 would probably bring in as good dividends as the other. 



Combe Raleigh Rectory, Honiton. W. Downes. 



UNDERGROUND HEAT. 



Sir, — I have read Mr. Starkie Gardner's article in your Magazine 

 for September, with much interest. I understand him to maintain 

 that the surface of the earth is solid from cooling, and the centre 

 solid from pressure, but that between the two there is a fluid stratum 

 of no great proportionate thickness ; he seems to think also that the 

 continuity of the liquid stratum is in some degree interrupted by 



