350 SECTIONAL TRANSACTIONS.— G. 



so simply to the presence of some ' coking ingredient,' nevertheless, it should be 

 possible to deduce the coking properties of a coal from its chemical constitution. The 

 • resins, and to a certain extent the hydrocarbons, appear to play the part of 

 agglutinating materials, but it is clear that the character of the infusible part of the 

 coal is of equal importance. 



Followed by Discussion. 



Mr. J. Ii. Hodgson. — An Examination of the Problem of Utilising the 

 Earth's Internal Heat. 



The paper attempts to collect the essential data and to formulate the principal 

 difficulties which bear upon the problem of utilising the earth's internal heat, and to 

 present these in a form convenient to engineers. 



The earth's total reserve of heat, the heat lost by radiation into space, and the 

 amount of heat produced by radio-active materials in rocks are estimated. 



The distribution of radio-active materials and their effect on the temperature 

 gradient of rocks is discussed. 



Reasons for assuming that the interior of the earth is getting hotter rather than 

 cooler, and is solid rather than liquid, are given. 



The rates of heat leakage from a cylindrical bore-bole in the centre of a hot slab 

 of heat-insulated material which (a) does not contain radio-active material, and 

 (6) which does contain radio-active material are calculated, and the ' heat leakage, 

 time ' curves are plotted. 



The heat yield under steady flow conditions for a deep heat bore-hole is also 

 estimated. 



Means for making such deep bore-holes are considered, and details such as the 

 use of cooling suits for the workers and the choice of the most suitable circulating 

 liquid for the bore-holes are briefly discussed. 



The probable heat yield from a deep heat bore-hole is compared with the yield 

 of a modern boiler, and the apparently insuperable difficulties introduced by the 

 combination of distance and the low heat conductivities of rocks are emphasised. 



The paper closes with an account of what has already been done in utibsing the 

 heat available in hot surface rocks, which are usually porous or fractured, and in 

 which heat bore-holes can be put down at frequent intervals without undue expense. 



A summary of the data, the formal mathematical proofs, and certain of the 

 technical details are given in the appendices at the end of the paper. 



Afternoon. 

 Visits to Textile Works : — 



Messrs. Hudson, Sykes & Bousfield, Morley. — Cloth manufacture from spinning 

 to finished piece : modern power plant. 



Messrs. Joshua Wilson & Co. — Woollen and worsted goods. 



Messrs. WilUam Lupton & Co. — All processes of woollen manufacture (initial 

 stages at Cliff Mills, Pudsey ; finishing processes at Leeds). 



Messrs. W. E. Yates, Bramley. — All processes of woollen manufacture. 



Saturday, September 3. 



Excursion. 



Smeaton's House. Selby. Goole Waterworks overhead tank (capacity, 750,000 

 gallons, height 155 ft.). 



Goole Docks — Inspection and lunch (Lowther Arms Hotel) by invitation of Aire & 

 Calder Navigation Co. Compartment train for coal. The compartments are loaded 

 at the mines, conveyed on bogies to the canal and towed down in trains. At the docks 

 are hydrauUc hoists which tip the compartments complete into the steamers. New 

 dock construction ; the debouchment of the New River Don. 



Ferrybridge Power Station.— The Ferrybridge Super-Power Station of the York- 

 shire Electric Power Co. is one of the newest in the country. There are at present 

 installed two 19,000 K.W. generating sets, but the ultimate capacity is 180,000 K.W. 

 In the circulating pump house is the experimental axial flow pump which forms the 

 subject of a paper in Pontefract. 



