November 17, 1910] 



NATURE 



91 



rained in the coal, consisting principally of fixed 

 nitr<^en. 



It IS in the process of transformation of coal into work 

 in the form of heat and power that the great loss occurs, 

 as this is always a most difficult process, and requires the 

 highest scientific and practical skill to carry out with even 

 very moderate economy. 



It has been proposed, with the view of accomplishing 

 the above ends, to treat the coal at central stations and 

 turn it into gas and distribute the energ>' in this form, 

 but this process onh" goes a small way towards a solution 

 of the problem, as under it combustion — which is such a 

 difficult problem — would be taking place at numerous 

 points over the whole country, all tending to inefficiency, 

 and the conversion of the gas into power is by no means 

 easy, involving running machiner\- of the reciprocating 

 class, requiring special and skilled attendance. 



It appears that with a problem such as we are dis- 

 cussing it is fundamental that the energ\- in the coal 

 -hould be converted at as few centres as possible into a 

 form in which it is most generally applicable to all pur- 

 poses without exception, and in which it is most easily 

 applied to all our wants, and is, at the same time, in a 

 form in which it is most difficult to waste or use 

 improperly. 



U'e are therefore forced to the conclusion that the only 

 complete and final solution of the question is to be obtained 

 by the conversion of the whole of the coal which we use 

 for heat and power into electricity, and the recover}.' of 

 its by-products at a comparatively small number of great 

 f lectricity-producing stations. All our wants in the way of 

 light, power, heat, and chemical action would then be met 

 by a supply of electricity distributed all over the country. 



It must, however, be remembered that the distribution of 

 energy in the form of etectricit>- instead of coal can onlv 

 be effectively carried out when it can be done in such a 

 way that it is available for all the purposes for which 

 coal is now used, and this can only be the case when the 

 conversion is effected at such an efficiency as will cause the 

 electric energy delivered to represent a high percentage of 

 the energy in the coal. Failing this, no scheme for con- 

 version at the pit's mouth and delivery of energv in the 

 form of electricity is sound. There is also another con- 

 trolling factor which must be satisfied in order to make 

 •his scheme possible. Both the conversion of the coal into 

 electricity and the distribution of the current must be 

 ffected at a k»w capital cost, so as not to overburden the 

 undertaking with capital charges. 



Considering the various processes of conversion which 

 nre now available, or may be invented, and their 

 possible and probable efficiency, we first come to electric 

 ilenerators driven by reciprocating steam engines. Their 

 conomy, expressed in the form of energ>- in the coal to 

 ■electric energ}-. may be taken as a maximum of lo to 

 12 per cent. This is, of course, far too low an efficiency 

 ta make any scheme such as I have already indicated 

 possible, besides which the capital expenditure and the 

 1 omplication involved are far too great and the size of the 

 units too small to be thought of for the punx)se in view. 



-We next come to large steam turbines such as have been 

 constructed up to the present, and see that their maximum 

 tficiencv mav be put down at about 17 to 18 per cent. 



Next in the list, in order of economv, comes the big 

 -ias engine fed from gas producers, with an elficiencv of 

 ■ oal energv to electric energv of possiblv 25 per cent. 



In the future we have to look towards two other means 

 of conversion — the gas-turbine-driven electric generator and 

 the production of electricity in some more direct wav from 

 the coal : but these two means of conversion, although 

 being capable of giving the most efficient results, are so 

 much in th° distance that they are quite bevond our 

 present consideration. 



-After ver\- careful thought on the subject I have come 



to the conclusion th.qt, in order to supplv electricitv for 



ill purposes, it would be necessary, amongst other things. 



> have n conversion efficiency of not less than 25 per cent. 



For the purpose of looking into this question I have 



taken the figures of production and consumption given in 



the report of the Roval Commission on Coal, which clearlv 



-ummarises the position as it stood a few vears ago. and 



is the increase taking olace is fairlv regular these fiaures 



have be«-n taken throughout. .According to this report 167 



NO. 2142, VOL. 85] 



million tons of coal were being used in the country in 

 1903. Of this amount 2 million tons went to coasting 

 steamers and 15 million tons were used by the gas com- 

 panies. In order to simplify matters and make the figures 

 clear, I have left out of consideration the coal used on 

 these two items, and taken the balance — viz. 150 million 

 tons — as the annual coal consumption of the countr}". If 

 now, instead of using this coal for doing work, as at 

 present, we were to convert it into electricity, we should 

 use, instead of 150 million tons, 60 million tons of coal a 

 year. This coal, turned into electricity, would produce 

 131,400 million Board of Trade units, and the electricity 

 so produced would, after allowing for losses of transmission 

 and conversion into work of different kinds, be sufficient 

 to supply the whole of our requirements now being satisfied 

 by the use of the 150 million tons of coal which we now 

 burn. 



Summarising the whole position, it may safely be said 

 that, wherever coal, gas, or power are now used, every- 

 thing for which they are used will be better done when 

 ! electricity is the medium of application. 

 I Hardly less in importance in the all-electric scheme is 

 the question of the by-products which become available by 

 j the proper use of our coal. These consist principally of 



fixed nitrogen, together with tar and oils. 

 I Fixed nitrogen in the forms of sulphate of ammonia, 

 [ nitrate of soda, and nitrate of lime are most valuable 

 I fertilisers, and enable land continually to produce the 

 j same crops with a greatly increased yield per acre. Much 

 i has been done in finding out how best to utilise thes»^ 

 j artificial fertilisers, but no doubt a great deal more will 

 j be done in this direction, and fertilisers will be prepared. 

 I with fixed nitrogen as their principal constituent, which 

 ! best suit the particular soils and crops that it is desired 

 i to deal with. 



According to last j-ear's Board of Trade returns, we 

 now grow about 23 per cent, of the total wheat that we 

 use and import 77 per cent. Of the barley used we grow 

 59 per cent, and import 41 per cent., and of the oats used 

 78 per cent, is home grown and 22 per cent, imported. 

 Last year we devoted 7I million acres to the cultivation 

 of these crops. 



Much is being done to improve the yield of corn crops, 

 j and it is probable that with scientific treatment in the 

 ; production of the seed, in the sterilisation of the ground, 

 and in the application of fertiliser, we may look at no 

 j distant date to an increased yield of 50 per cent, in these 

 crops upon what is now being produced per acre. The 

 [ most vital feature, however, in bringing this about, once 

 i we have acquired sufficient knowledge, is an ample supplv 

 of fixed nitrogen to use as fertiliser, and it is when con- 

 sidered from this point of view that a scheme which sup- 

 plies this from our coal as the result of saving present 

 waste is most important. 



With the increased yields which we have mentioned we 



could produce corn crops sufficient to supply the whole of 



our requirements upon 11 million acres. This would re- 



: present 233 per cent, of our present cultivated area, and 



would only be an addition of 3^ million acres to the land 



j now used for the purpose of growing these same crops. 



The value of these additional crops would be about 58 



I millions sterling, based upon the prices which we paid 



I last year, and to this would have to be added the value 



of the straw and the other wheat by-products, which would 



\ go a long way towards providing the food for growing 



j the additional meat which we require to supply our demand 



} at home. 



I In order to fertilise the land we should have available. 

 I under the all-electric scheme, 3 million tons, or its nitrogen 

 equivalent, of sulphate of ammonia. This, if used over the 

 ! whole of the 46I million acres now under cultivation, 

 would give 143 lb. per acre : but, of course, the fertiliser 

 would be distributed according to the nature of the land 

 and the crops being grown. It is probable that in these 

 circumstances the increased yield of" the land now culti- 

 vated would not only give us all the grain that we should 

 require for food, but also all the foodstuffs, partlv as 

 by-product from the grain and partly grown, that would 

 be required for raising the cattle, sheep, and other animals 

 necessary to suoplv the whole of our wants. 



It is now beginning to be understood that intensive 

 farming of the land also involves intensive cattle raising. 



