THUNDER STORMS. 93 
But, as the particles both of air and vapor are feverally 
too minute to fall under our notice, I fhall endeavour to 
illuftrate by analogy what cannot be dire&tly demonftrated 
by experiment. In order to this, I fhall firft give a ge- 
neral defcription of, and then fubjoin fome obfervations 
upon doctor Prieffley’s electrical battery. 
This battery confifted of fixty four cylindrical glafs jars 
fixed in a fquare box; the jars were coated within and 
without with tin foil, and the floor of the box was cover- 
ed with the fame, whereby the outfides of all the jars 
formed but one continued ele¢trical furface. In like man- 
ner, by means of {mall brafs bars extending over the 
mouths of the jars in their feveral ranges, and by- wires 
which connected the feveral bars, together with others 
which defcended from them, communicating with the in- 
ner coating of each jar, their interior furfaces were fo 
connected as to form, in the fame fenfe, but one furface.. 
Thus conftructed, the whole battery is capable of being 
equally charged in every part at the fame time, and of be- 
ing difcharged throughout by the fame explofion. 
Here I would obferve, that if, inftead of the metalline 
coatings, the jars were filled with water to the fame height 
with them, and were immerfed in the fame order in a 
{quare veffel of water to an equal depth, the bars and wire 
remaining as before, the fuccefs of all the experiments 
made with them would be the fame as above. Let thena 
battery be conftructed and charged in this form; after 
which let the bars and wires aforefaid be removed, and 
the water contained in the jars be decanted off by glafs 
fyphons, and let the water be drawn off from the veffel in 
which they ftand. It is evident from the experiment of 
the charged pane of glafs already mentioned, and other 
experiments recited in doctor Franklin’s letters, that thefe 
jars will remain /everally charged, as they were jointly 
before. They may now, when dry, be taken out and 
handled at pleafure with fafety ; nor can they be eafily re-. 
ftored: 
