APPENDIX 
ELECTRICITY 
25th October 1768, about five miles south of the line. 
My machine was made by Ramsden, and worked by a flat 
plate 8 inches in diameter. The phial used was 64 inches 
in height and 54 in diameter without the neck; the distance 
between the stopper and the coating, 3 inches, the stopper 
made of wood and fastened to the glass on the inside by a 
red cement (probably sealing-wax), The electrometer was 
divided into thirty parts of 14 inch as nearly as possible. 
About nine in the morning the machine was set up, the day 
being rather cloudy, and the ship going between three and 
four knots. 
When the plate was first turned round the cushions 
appeared to be damp, adhering to the glass so much that it 
was with difficulty made to move very slowly, although the 
cushions were screwed on as tightly as possible. After 
wiping them very well the plate was made to go round, 
and in about ten minutes electricity was excited, though 
but in a small degree ; the motion of the ship and the shaking 
of the table, caused by turning the machine, made the 
electrometer (which was a very unsteady one) move back- 
wards and forwards visibly, so that it was impossible to 
ascertain exactly at what distance it discharged the phial, 
it however was guessed to be about a line when at the 
greatest distance. 
It continued to work in this manner about half an hour, 
in which time several attempts were made to give a shock, 
but they succeeded very badly, the shocks being very slight, 
