[ + 7 ° ] 
enlarged. In other words, certain accidents making 
the rays more divergent than they otherwife would 
be, at their entrance into the eye, ieem to me to be 
the caufe of thefe and other like appearances. 
20. On any evening, when the Iky is very clear and 
ferene, and the Moon high, if the fky near the ho- 
rizon, all around, be obferved, it will appear, to the 
naked eye, more white and light than any other part, 
except that part of the fky which is near to the Moon. 
The like is obfervable, when the Moon doth not 
fhine. This feems to prove, that when the Moon’s 
light has fallen promifeuoufiy on the vapours of the 
atmofphere, it is more copioufiy reflected from the 
vapours neaf the horizon, than from thofe in a di- 
rection toward the zenith. And thus, it feems, they 
mult, in proportion to the depth and deniity of the 
one, compared with the depth and deniity of the 
other. The fame feems to be confirmed, by the 
burning of a candle, or other light, in a fog; for, 
then, it appears to give a ftronger blaze of vaporous 
light, within that certain fphere it illuminates, than 
it doth in true permanent air, and yet the rays extend 
farther in the latter cafe, than in the former. 
2 r. When a number of candles, lamps, torches, 
or other lights, are placed at equal clidances from 
each other, in a row a mile or two in length, and a 
fpeClator ftands at one end of the row, viewing thofe 
lights, the nucleus of the neared light will appear 
whited and brighted, and bed defined ; but looking 
onward to the red, they will appear more and more 
red, dull, and faint, the farthed will not appear 
larged, nor the neared, but fome intermediate one, 
at a certain didance from the neared. Hence there 
is 
