r + i8 ] 
Franklin’s queflions are of fome importance, and de-*- 
ferve a ftridt difcuflion. 
Upon the fuppofition that light is a copious ema- 
nation of innumerable fmall particles of matter from 
the fun, I had once occafion to enquire, what the 
force of motion produced in every fuch emiffion could 
poflibly amount to at the utmoft. 
For this purpofe, I made nneflimate of the greateft 
probable magnitude of the particles of light ; and of 
the greateft denfity of each. 
I likewife computed the greateft number of fuch 
particles, that could poflibly fly oft at once from 
the furfaceof the fun j fuppoflng the fun’s horizontal 
parallax to be no more than 8". 
Thefe computations, with an account of the prin- 
ciples on which they were founded, having been al- 
ready given to the public 2 ; I fhall make ufe of the 
refults (which I (hall here briefly ftate) as data for 
the difcuflion of Dr. Franklin’s queftions. 
I fuppofe the particles of light to be equal fpherules.. 
This, perhaps, is not the cafe. Each color has proba- 
bly its own flze ; but, there will be a mean flze, 
which is fufiicient for my purpofe. 
This mean flze I fuppofe to be fo fmall, that the 
diameter of each fpherule does not exceed one mil- 
lionth of one millionth of an inch. I fhall fhew here- 
after, that there is much reafon to fuppofe, that the 
particles of light are in fa<5t much lefs than fpherules 
of this diameter. 
* In a little treatife, entitled. The Power of God, deduced 
from the computable inftantaneous Productions of it in the 
Solar Syftem. 
I fup* 
