( \6 ) 
of the Times will be difcovered, which will ferve 
for ever afterwards, as a Rule to ad juft the Observa- 
tions. 
The only View that I have in communicating 
this Paper, and in computing the Eclipfes for Time 
to come, is to encourage thofe Perfons, who will find 
their Advantage in it, to make Ufe of this Help 
for obtaining the Longitude at Sea, till better Me- 
thods are offered. 
V Experiments and Obfervations upon the 
Light that is produced by communicating Elec- 
trical Attraction to animal or inanimate ©o- 
dies, together with fome of its mojl furprijhg 
Effects 5 communicated in a Letter from Mr. Ste- 
phen Gray, F. <!{. S • to Cromwell Mortimer, 
M. 2). % S. Seer. 
SIR, Chart er-Houfe, Jan . 28th, 1734-5. 
I T is now fome Months ago that I promifed to give 
the Society an Account of what Experiments I 
had then made ; but foon after there occurred to my 
Thoughts feveral others, which I was willing to try 
the Succefs of ; which Experiments requiring an Ad- 
dition to the apparatus , that I might make them 
more compleat, I hope will be a fufficient Apology 
for this Delay. 
I fee you have publifhed Mr. Dufays Letter to 
the Duke of Richmond, in the PhiJoJophica / Tranf- 
anions. 
