384 



SCIENCE, 



[Vol. IV., No. 89. 



and the modification of Plante's simple lead cells; the 

 simple cell being two plates placed in a dilute sul- 

 phuric acid, one plate oxidized, and the other plate 

 pure. Now, as regards the uses, I have made a great 

 many experiments with these secondary batteries; 

 and first I will speak of the experiments made of 

 their use in telegraphy. Some time ago the idea was 

 mooted that a considerable economy might be effected 

 in the working telegraph if dynamos were used for 

 that purpose. The dynamo-machines are used by the 

 Western union company, and they employ them for 

 their circuits; but they are not used in England, and 

 we have failed to use them for a very obvious reason, 

 which is simply this, that in England we do not work 

 with ' closed circuits.' We work our instruments 

 with rapid reversals; our automatic system, which 

 is so very extensive, sometimes giving us the result 

 of the transmission of three hundred words per 

 minute, with very rapid reversals . of very minute 

 currents. It is absolutely essential that these currents 

 should be uniform in their character. Now, the cur- 

 rents produced by the dynamo-machines are not 

 uniform. If a telephone be inserted in a secondary 

 circuit, you will invariably find that you can hear 

 sounds which are indicative of variations of the cur- 

 rent, and these variations are fatal to a fast speed of 

 working. But when you use a dynamo, and utilize 

 the current of the dynamo in preparing a secondary 

 battery, you then get a means by which you can pro- 

 duce currents of absolute uniformity. The second- 

 ary-battery current flows out absolutely uniform. 

 And, again, it has the great advantage of giving you 

 a battery with a very low resistance. The electro- 

 motive force of an ordinary cell is as low as two 

 volts. You may take it as a rule to be two volts. 

 Its internal resistance may be made whatever you like. 

 Now, I had three series of cells made, one set being 

 Dr. Tribe's, and another Plante's: and from each 

 of these sets — there were eight cells to each set — 

 from each of these sets forty circuits were worked; 

 that is, each battery had forty distinct and separate 

 circuits, so that practically we had a hundred and 

 twenty circuits running from these three secondary 

 batteries. Although all worked for about three 

 months, I think the exact time was ninety-six days, 

 all these circuits worked uniformly and perfectly, 

 gave no trouble that would necessitate even the glan- 

 cing at them during this whole period of three 

 months, and without any attention; when suddenly 

 one failed, and immediately afterward another failed, 

 and then the third failed. They were charged up 

 again, and then they went on for another three 

 months. And they have behaved as well as one could 

 possibly wish; so much so, that one of the first duties 

 that I wish to discharge, on my return to England, 

 will be to arrange for a large supply of these second- 

 ary cells, and a further use on a large scale at our bat- 

 tery for the post-office. We have in use, at the general 

 post-office in London, six hundred and fifty circuits 

 centralizing there; and we are now utilizing about 

 twenty-two thousand cells. I think it more than 

 likely we shall be able to work the whole with proba- 

 bly not more than five thousand cells. 



Now, as regards electric lighting. I have already 

 used secondary batteries for electric lighting: I have 

 used them in the post-office, and I have used them 

 for my own house. My house is in a portion of the 

 country through which no lines pass for the purpose 

 of electric lighting, and they cannot be found within 

 a reasonable distance : so, if I wanted to light my house 

 by electricity, I must be dependent on my own supply 

 of electricity. I light my house by gas: but I burn 

 my gas in my garden, and I extract from it that which 

 I want, namely, light; and I discharge into the air of 

 my garden that which I do not want, namely, poison. 

 My gas is employed in working a small gas-engine of 

 two-horse power. It is the gas-engine which works a 

 small Gramme dynamo, which, when worked at its full 

 power, gives me forty-two volts and fifty-two amperes. 

 These fifty-two amperes are directed into seventeen 

 cells. The cells are Plante's original cells. The plates 

 themselves are two feet square, and in each cell there 

 are twelve of these little lead plates. The lead plates 

 are made up of four thin sheets of lead, each sheet be- 

 ing about one thirty-second of an inch thick; and they 

 are perforated in squares regularly all over, and these 

 four thin plates are tied together — they are almost 

 woven together — they are tied together with thick 

 worsted. They are arranged in pairs ; six on one side 

 forming one pole, and six on the other side forming 

 the other pole. They are placed inside of an ordinary 

 pitch-pine box, and the insulation of the cell is main- 

 tained by a thin India-rubber bag which envelops it. 

 It is a loose India-rubber bag of about the same shape, 

 and, when the plates are put in, it forces the India- 

 rubber out, and the bag takes the exact form of the 

 cell, and it makes the cell thoroughly water tight and 

 thoroughly electricity tight. I have seventeen of 

 these cells, all arranged in a series; and my engine, 

 which generates these currents, and charges this bat- 

 tery, is in my garden. My gardener has the gas-engine 

 under his charge. He is an ordinarily intelligent 

 gardener. When he comes on duty in the morning, 

 he lights the gas in the gas-engine, and starts the 

 dynamo which charges my battery; and when he goes 

 away to his dinner, after the engine has been work- 

 ing for three or four hours, the battery is prepared. I 

 go home in the evening: I have got a store of elec- 

 tricity. I have every room in my house fitted up. I 

 have at my bedside a most charming little light, with 

 no smoking, and no trouble with a wick, and no heat, 

 — a mellow light by merely turning on my tap. I have 

 the softest and most delicious light you can conceive 

 of, thrown upon my paper or thrown upon my book. 

 I have had this going on for four months, and I have 

 never had any bother, except on one occasion, when 

 the gardener put his foot on the wrong place, and the 

 engine came down upon his foot, crushing his toes. 



I have a strong impression, that, for all isolated 

 places similar to mine, the storage-battery is an essen- 

 tial thing, and I think that some one is bound to work 

 out this question. Several are now pegging away at 

 it. Sir William Thomson spent much time in inves- 

 tigating this subject, and has given it a great deal of 

 attention, but has not succeeded, simply because you 

 can use a Plante cell untrammelled by any patent. It 



