5 86 



NA TURE 



[Oct, 1 6, 1884 



cerned ; if 50 or even 10 per cent, could be stored in such 

 a way as to be conveniently available, it would be of con- 

 siderable value, and any arrangement capable of effecting 

 this storage could only with injustice be stigmatised as 

 wasteful. The solar energy of the Carboniferous epoch 

 has most of it been wasted ; but a small fraction — probably 

 not a millionth per cent. — has been saved and stored in the 

 Coal-measures. It is possible to abuse the coal for not 

 having stored more, but we find it a useful modicum 

 nevertheless. 



(2) A second case when the advantage of storage over- 

 balances the loss is when regularity and continuity of 

 supply is needed, and when the source is irregular and 

 fitful. Wind and wave power illustrate this kind of 

 source ; it is manifest that wind power has not been so 

 largely used as it would have been, had it been steady 

 and dependable. A practicable method of storing up its 

 energy and giving it out as wanted would gradually cause 

 it to be very largely employed. This case is also illus- 

 trated faintly by a gas-engine or jerky motor of any kind, 

 and the regularity and dependableness of a storage cistern 

 may very well make it desirable to put up with some waste 

 provided it be not excessive. Mechanical devices for 

 approximating to regularity, such as the use of slack 

 driving belts, undoubtedly give rise to a waste of power, 

 and so does any form of regulator. But in the utilisation 

 of artificial forms of power like this, questions of economy 

 become almost pre-eminent ; and wastefulness is here a 

 most serious objection, and, it may be, prohibitive defect. 

 At the same time, if the engine is liable to stop, or if it is 

 not always working, some mode of storing energy may be 

 absolutely necessary, whether wasteful or not. 



(3) Another case, and to some extent the converse of 

 the last, is when the available source is weak, though 

 continuous, while the power, is only needed for a short 

 time, but during that time is required to be great. This is 

 exemplified in the operation of pile-driving, where energy 

 is stored in the slowly-raised weight to be suddenly ex- 

 pended on the head of the pile, also in the operation 

 of drawing a bow ; or again when a small waterfall or 

 steam-engine, running continuously, is to be utilised for 

 lighting during five or six hours each day : the obviously 

 right plan in such circumstances as these is to store the 

 energy during the hours it is not wanted, and thus virtu- 

 ally to double or treble the power of the source while it 

 is actually in use. Unless, however, the loss occasioned by 

 storage were reasonably small, there would be but small 

 gain in attempting the process in this third case. 



It is plainly advantageous to devise a method of storing 

 that shall give out the greater part of what is put in ; but 

 we see by these examples that a reasonable loss may be 

 more than compensated by convenience, regularity, avail- 

 ability, and dependableness. Again, when energy has to 

 be transmitted over great distances, it is in practice diffi- 

 cult or impossible to make the expenditure of energy at 

 one end depend upon and be regulated by its consump- 

 tion at the other ; and so, without some system of storage, 

 great waste will ensue during intervals of small consump- 

 tion. Looking to the immense development which the 

 transmission of energy may be expected to undergo in 

 the course of the next few decades, a convenient and 

 manageable method of receiving large quantities of trans- 

 mitted energy, and of holding it in readiness until wanted, 

 must be of prime importance. 



It was in view of such applications as these that the 

 invention of the storage battery by Faure was hailed with 

 enthusiasm by the highest scientific authority in Great 

 Britain ; while the public, jumping to the conclusion that 

 a thing for which so many uses could be instantly found 

 must needs be a profitable investment, hastened to pro- 

 vide money, not for commencing careful experiments and 

 perfecting the arrangement, which would have been wise, 

 but for manufacturing tons of apparatus in its first crude, 

 immature, and untried form. Some day it may perhaps be 



recognised that because it can be shown that a thing will be 

 extremely useful when perfect it does not follow that it has 

 already attained that perfection, that indeed probabilities 

 based on historical developments are enormously against 

 such abnormal and instantaneous maturity, and that the 

 careful nursing and rearing necessary to healthy maturity 

 are better given in the seclusion of laboratory and study 

 than in the excited and heated atmosphere of the Stock Ex- 

 change. It is doubtless recognised already that all prelimi- 

 nary operations are better conducted on a scale smaller 

 than the wholesale manufacturing one. In developing a 

 new industry there are scientific difficulties to be overcome, 

 and there are manufacturing difficulties. By scientific 

 difficulties we mean such as the determination of weak 

 points, the best ways of strengthening them, and generally 

 the discovery of theoretically the best modes of effecting 

 the object in view : manufacturing difficulties begin with 

 questions of expediency and economy — how most cheaply 

 and satisfactorily to carry out the indications of theory, to 

 obtain this or that material — and include the organisation 

 of a system of manufacture, of division of libour, of 

 machine tools, which shall enable the work to be done 

 with economy, security, and despatch. Over-haste in 

 the preliminary stages causes both these sets of diffi- 

 culties to be tackled together, and so throws a grievous 

 burden on both adviser and manager. All these un- 

 toward conditions have storage batteries experienced ; 

 and to say they have not fulfilled the hopes of their early 

 promoters is no more than to say that those hopes were 

 untimely and unreasonable. The period of maturity has 

 been undoubtedly delayed by injudicious treatment, but 

 its ultimate attainment seems to us inevitable ; and it is 

 at present a matter of opinion how nearly it has already 

 been reached : certainly great steps towards it have been 

 made. Let us inquire what some of the difficulties en- 

 countered have been, and it will be seen that, formidable 

 as some of them are, they belong essentially to an infantile 

 stage, and are not suggestive of constitutional debility. 



The first form of manufacture consisted in rolling up 

 sheets of lead and composition, with trousering to keep 

 them separate. The difficulties found were that the 

 coatings would not adhere, but became detached in large 

 flakes ; that the trousering got corroded through and per- 

 mitted short circuiting ; and that free circulation of fluid 

 being impossible, the acid became exhausted in some 

 places and concentrated at others, and thus every sort of 

 irregularity began. Now regularity or uniformity is of 

 the most vital and fundamental importance in any form 

 of battery. If any part of a plate is inactive, that part is 

 better away ; if any plate in a cell is inactive, it is better 

 away ; and if any cells of a battery are inactive, they are 

 infinitely better away. The rolling or coiling up of the 

 sheets being found awkward in practice and liable to 

 detach the coatings, flat plates came to be used, then 

 perforated plates, and then cast grids ; these last having 

 such large hole space that they held enough composition, 

 and held it securely enough, to enable the trousering or 

 intermediate porous material to be dispensed with. This 

 was an evident step in advance : free circulation of the 

 liquid became possible, and could be assisted by stirring; 

 there was nothing to corrode except the plates themselves, 

 and the composition, being in the cells or holes of the 

 grid, might be reasonably expected to adhere. So far 

 expectation was not altogether belied. The adhesion was 

 not perfect, it was true, and pieces of composition some- 

 times fell out of the holes, especially if too powerful currents 

 were passed through the cell, but still it was much better 

 than it had been ; and if the plates were well filled, properly 

 formed, and fairly treated, the composition adhered ex- 

 tremely well and securely. The circulation of the liquid 

 was not automatically perfect either, but mechanical agi- 

 tation could be readily applied ; without it the acid near 

 the bottom of the cells tended to become more concen- 

 trated than that near the top, not by reason of gravitation 



