in Electricity. 67 1 
very good during all the time I left them in a room con- 
ftantly warmed, which was about two months ; but, when 
they were placed in a cold room, they foon loft their power, 
having probably attracted moifture from the air. I can- 
not be fure that the varnifh I got made for the purpofe 
was of the beft kind : I have reafon to fufpeCt the con- 
trary, and therefore I fhould think that much better 
might be obtained in London. 
Such pafte-boards might be poflibly preferved from 
attracting moifture, by keeping them fhut up in a box 
made on purpofe, lined within with tinfoil. The 
moifture might alfo be expelled again by placing them 
a good while in a heated room, or upon a baker’s 
oven. 
It feems, befides, not improbable, that a kind of pafte- 
board might be made by flicking together the lamina of 
paper (firft thoroughly dried) with a good oil varnifh in- 
ftead of common pafte, as this laft never can be deprived 
of its watery particles without lofing its cohefive quality. 
A good kind of pafte-board might likewife be contrived 
by flicking together filk cloth inftead of paper. 
I contrived a plated machine, the disk of which was 
made of baked wood and boiled in 1 infeed oil; but it did 
not anfwer near fo well as the pafte-board disks. 
4S2 
I found 
