£ 4 20 1 
collected the rays of the fun by the convex glafs, 
and held it at luch a diftance as to bring the focus 
exactly upon the end of the box, which was burnt 
very black, and the glue in the joints melted; but 
the balls were not in the leaft affeCted. 
Extract from Mr, boyle’s Continuation of 
hawkesby’s Phyfico-mechanical Experi- 
ments. 
“ I took a large piece of good amber; and, 
“ having in a fummer-morning (while the air was 
“ yet frefh) tried that it would not, without being 
“ excited, attract a light body I had expofed to it, 
“ I removed it into the fun’s beams, till they had 
“ made it moderately hot ; and then I found, as I 
“ expelled, that it had acquired an attractive 
<c virtue, and that not only in one particular 
“ place, as it is ufualty obferved when it is ex- 
“ cited by rubbing, but in divers and diftant 
«« places at once ; at any of which it would draw 
“ to it the light body placed within a convenient 
“ diftance from it ; fo that, in this climate of 
“ ours, a folid body may quickly acquire an at- 
«« mofphere by the prefence of the fun, and that 
« long before the warmeft part of the day.” 
ANOTHER. 
«'« I took a little, but thick, veflel of glafs, and 
“ held it near the fire till it had got a convenient 
“ degree of heat , which was not very great, 
“ though it exceeded that of the amber. I found, 
11 as I imagined, that the heat of fire had made 
“ even 
