Charles William Pasley to Faraday   14 January 1839

Chatham the 14th of Jany | 1839

My dear Sir,

I never paid the smallest attention to the Voltaic Battery, until it appeared to be a better agent for firing Gunpowder under water than any other. To this particular application of its powers, I shall stick, I mean ‑apply without intermission, until I get its use reduced to something like certainty.

Since I wrote you last¹, it has occurred to me, that a description of some our failures may not be unacceptable to you. I will describe them.

1st Passing the wires through a wooden top or lid of a waterproof box in which they were jammed tight as in the annexed sketch

the powder being in a bag B covered with water proof composition, and the wooden lid also being coated with a waterproof composition, ignition did not take place.

2dly. When the wooden lid was planed smoothe, [sic] without any water proof composition over it, the same failure occurred, owing to the tightness of the wires.

Whether we left the copper bare and ex‑posed to the water above the wood, or whether we inclosed it in tape (the tape not being coated with water proof composition[)], the effect was the same. The powder would not explode.

3dly. On enlarging the holes in the wood, so that the copper wires were not jammed, the explosion always took place, whether they touched the wood on one side or not, and whether the copper was naked or covered.

4th. When we passed the platinum wire through a small tin case containing the powder, and soldered it into the tin as well as to the ends of the copper wires, it failed.

4th [sic] When we passed the platinum wire though a tin case as before, but did not solder it to the side of the case merely putting our water proof composition into the holes, the explosion took place, but we finally abandoned tin and preserved the bag. -

5th. When the platinum wire was fixed round the copper wires by passing it round and round and drawing it close by a pair of pincers, ignition generally failed. When its ends were soldered to the copper, it never failed except from causes not depending on the mode of connection. Even in the open air our battery would not make the platinum wire red hot, when merely passed round the copper, without soldering or pressure.

6th. It being absolutely necessary, that the copper wires should be firmly fixed to the wooden lid, in order to prevent a pressure from without, or tension from without, which might by altering their position break the platinum wire, we tried to fix them on the outside of the lid by making a loop or hole in each of the copper wires thus, and fixing others to the wooden lid, and passing a pair (PP) horizontally through them all, as represented by the dotted lines. In this case the experiment failed. We therefore screwed the wires up to the bottom of the lid inside, as represented in the first figure in my former letter, and this has always succeeded.

7th. On passing both wires tightly through corks inserted into the lid of hard wood, ignition took place. 8th. On covering the top of each cork and also the top of the hard wood of the whole lid with water proof composition, the experiment failed. 9th. On covering the corks alone, but not the hard wood with this composition an explosion took place, but this partial coating of the corks only would not answer my purpose, because I know that water will force itself through the pores of wood at the great depths at which I contemplate using the Voltaic Battery, namely from 80 to 100 feet.

Mr Daniel[l] has repeatedly expressed his surprise to me that the first experiment recorded in this letter should have failed, his opinion being, that it ought not to have failed, but we have tried the thing too often to have the smallest doubt of the fact, and I observe in one of your Papers, that you found that ice prevented the action of a powerful battery, which you say was unfore‑seen by you².

I beg to know, whether there is any objection to our japanning or painting the outsides of the copper cylinders or cells of our Daniell's Battery³. Should it do no harm, it will be convenient, and prevent verdigris from collecting?

I remain my dear Sir | yours very faithfully & obliged | C.W. Pasley

NB. I also beg to know in what way you compare the powers of a Daniells Battery with one of Dr Woolastons [sic].