o4 



NATURE 



[September ii, igig 



the size of the generating units, and the size of the 

 area to be supplied. On one hand, a comparatively 

 small number of very large or super-stations, instead 

 of a large number of moderate-sized stations dotted 

 over the area, results in a small decrease in the cost 

 of production of the electricity, because in the super- 

 stations larger and slightlv more economical engines 

 are employed, while the larger stations permit of 

 higher organisation and more elaborate labour-saving | 

 appliances. Further, if in the future the recovery of 

 the by-products of coal should become a practical 

 realisation as part of the process in the manufacture 

 of the electric current, the larger super-statHans 

 present greater facilities than the smaller stations. 

 On the other, super-stations involve the transmission 

 of the electricity over greater distances, and con- i 

 sequently greater capital expenditure and cost of | 

 maintenance of mains and transmission apparatus, j 

 and greater electrical transmission losses, while the | 

 larger generating unit takes longer to overhaul or 

 repair, and consequently a larger percentage of spare | 

 plant is necessary. 



The greatest element in reducing the cost of elec- ■ 

 tricitv is the provision of a good load factor; in other i 

 words, the utilisation of the generating plant and 

 mains to the greatest extent during the twenty-four i 

 hours of each day throughout the year. This is a far j 

 more important consideration than the size of the 

 station, and it is secured' to the best advantage in j 

 most cases by a widespread network of mains, supply- | 

 ing a diversttv of consumers and users, each requiring j 

 current at different times of the day. The total load j 

 of each station being thus an average of the individual | 

 loads of a number of consumers is, in general, far j 

 less fluctuating than in the case of small generating j 

 and distributing systems, which supply principally one 

 class of consumer— a state of affairs that exists in 

 London, for instance, at the present time. It is true 

 that there mav be exceptional cases, such as at Kil- 

 marnock, where a good load factor may be found in 

 a small area, but' in this case the consumers are | 

 chiefly mills, which require current for many hours 

 dailv. 



There is no golden rule to secure cheap electricity. 

 The most favourable size, locality, and number 6f 

 generating stations in each area can only be arrived 

 aU by a close study of the local conditions, but there 

 is no doubt that, generally speaking, to secure cheap 

 electricity a widespread network of mains is_ in 

 most cases a very important, if not an essential, 

 factor. 



The electrification of tramways and suburban rail- 

 ways has been an undoubted success where the volume 

 of traffic has justified a frequent service, and it has 

 been remarkable that where suburban lines have been 

 worked by frequent and fast electrical trains there 

 has resulted a "reat growth of passenger traffic. The 

 electrification of main-line railwavs would no doubt 

 result in a saving of coal ; at the same time, "the 

 economical success would largelv depend on the 

 broader question as to whether the volume of the 

 traffic would suffice to pay the working expenses and 

 provide a satisfactory return on the capital. 



Municipal and company generating stations have 

 been nearly doubled in capacity during the war to 

 meet the demand from munition works, steel works, 

 chemical works, and for many other purposes. The 

 provision of this increased supply was an enormous 

 help in the production of adequate munitions, kt 

 the commencement of the war there were few steel 

 electric furnaces in the country ; at the end of last 

 year 117 were at work, producing 20,000 tons of steel 

 per month, consisting chiefly of high-grade ferro alloys 

 used in munitions. 



NO. 2602, VOL. 104] 



The Future. 



The nations which have exerted the most influence 

 in the war have been those which have developed to 

 the greatest extent their resources, their manufactures, 

 and their commerce. As in the war, so in the civilisa- 

 tion of mankind. But, viewing the present trend of 

 developments in harnessing water-power and using 

 up the fuel resources of the world for the use and 

 convenience of man, one cannot but realise that, 

 failing new and unexpected discoveries in science, such 

 as the harnessing of the latent molecular and atomic 

 energy in matter, as foreshadowed by Clerk Maxwell, 

 Kelvin, Rutherford, and others, the great position of 

 England cannot be maintained for an indefinite period. 

 At some time more or less remote — long before the 

 exhaustion of our coal— the population will gradually 

 migrate to those countries where the natural source's 

 of energy are the most abundant. 



Water-power and Coal. — The amount of available 

 water-power in the British Isles is very small as 

 compared with the total in other countries. Accord- 

 ing to the latest estimates, the total in the British 

 Isles is less than 1,500,000 h.p., whereas Canada alone 

 possesses more than 20,000,000 h.p., of which more 

 than 2,000,000 h.p. have already been harnessed. In 

 the rest of the British Empire there are upwards of 

 30,000,000 h.p., and in the remainder of the world at 

 least 150,000,000 h.p., so that England herself possesses 

 less than i per cent, of the water-power of the world. 

 Further, it has been estimated that she only pos- 

 sesses 25 per cent, of the whole coal of the world. 

 To this question I would wish to direct our attention 

 for a few minutes. 



I have said that England owes her modern great- 

 ness to the early development of her coal. Upon it 

 she must continue to depend almost exclusively for 

 her heat and source of pov^er, including that required 

 for propelling her vast mercantile marine. Neverthe- 

 less, she is usmg up her resources in coal much more 

 rapidly than most other countries are consuming 

 theirs, and long before any near approach to exhaus- 

 tion is reached her richer seams will have become im- 

 poverished, and the cost of mining so much increased 

 that, given cheap transport, it might pay her better 

 to import coal from richer fields of almost limitless 

 extent belonging to foreign countries, and workable 

 at a much lower cost than her own. 



Let us endeavour to arrive at some approximate 

 estimate of the economic value of the principal sources 

 of power. The present average value of the royalties 

 on coal in England is about 6d. per ton, but to this 

 must be added the profit derived from mining opera- 

 tions after paying royalties and providing for interest 

 on the capital expended and for its redemption as 

 wasting capital. After consultation with several 

 leading experts in these matters, I have come to the 

 conclusion that about is. per ton represents the pre- 

 war market value of coal in the seams in England. 



It must, however, be remembered that, in addition, 

 coal has a considerable value as a national asset, for 

 on it depends the prosperity of the great industrial 

 interests of the country, which contribute a large 

 portion of the wealth and revenue. From this point 

 of view the present value of unmined coal seems not 

 to have been sufficiently appreciated in, the past, and 

 that in the future it should be better appraised at 

 its true value to the nation. 



This question may be viewed from another aspect 

 by making a comparison of the cost of producing a 

 given amount of electrical power from coal and from 

 water-power. Assuming that i h.p. of electrfcal 

 energy maintained for one year had a pre-war value 

 of 5I., and that it requires about eight tons of average 



