228 
MicrRoOGRAPHIA. 
extend it felf more then as high again,nay, perhaps indefinitely, or 
beyond the Moon ; for the Elaters and Expanfions being in reciprocal 
proportions, fince we cannot yet find the plws ultra, beyond which the Air 
will not expand it felf, we cannot determine the height of the Air: for 
fince, as we have fhewn, the proportion will be alway asthe preffure 
faftain'd by any part is to 35. fo 1000. to the expanfion of that part; 
the multiplication or product therefore of the preflure, and expanfion, - 
that is, of the two extream proportionals, being alwayes equal to the 
roduét of the means, or 35000. it follows, fince that Rectangle or 
roduct may be made up of the multiplication of infinite diverfitics of 
numbers, that the height of the Air is alfo indefinite ; for fince (as far as 
I have yet been able to.try) the Air feems capable of an indefinite Ex- 
panfion, the preflure may be decreafed in infinitum, and. confequently its 
7 a ay a indefinite alfo. 
_ Experiment of the falt and frefh Water ) the ray 
“Jiquely through the Air alfo, which isof very diffe 
ae e being therefore fuch a difference of denfity, and no Experi- 
ment yet known to provea Saltws, or {kipping from one degree of rari- 
ty to another much differing from it, that is, that an upper part.of the 
Air fhould fo much differ from that immediately febjacent toit, as to 
make a diftinét fuperficies, fch as we obferve between the Air and Wa- 
ter, ¢c. Butit being more likely, that there isa continual increafe of 
rarity. inthe parts of the Air, the further they are removed from the 
furface of; the Earth ; It will hence neceflarily follow; that (as.in the 
of Light pafling ob- 
rent denfity, will be 
continually, and infinitely inflected, or bended, froma ftreight, or dire 
» This granted , the reafon of all the above recited. Phenomena, con- 
a appearance of the Celeftial Bodies, will very eafily be de- 
ucec As, Gana Vieme 28 Sec st 60 OF 31 W 
- Firft, The rednefof theSun, Moon, and Stars, will be, found, to be 
caufed by the infleGtion of the rays. within the Atmofphere. , That it is 
not really in or near the luminous bodies, will, [fuppole, be very eafily 
granted, feeing that this rednefs is obfervable in feyeral places differing 
in Longitude, tobe at the fame time different, the fetting and rifing:'Sun 
of all parts being for the molt part ted: Lor pAeds 9 asada} 
Andfecondly, Thatitis not meerly the colour of the Air interposd, 
will, , without much more difficulty be yielded, {eeing that.we - 
may. oblerve a very great interftitium of Air betwixt the ObjeCtand the 
Eye, makes it appeatof a dead blew, far enough differing from. a red, 
ently. , a if! 2vewils set 
_ > Fake.a {pherical Cryftalline Viol, fuch asis < 
Repainth-ahetsGde of the 
or yellow... 4 S3L OY iHi 901 O37 SHINO Gholi OF PSI0dGs 
-» But thirdly, That it proceeds from the refraGtion,or inflecion, of the 
_raysby the tnepbere, ths following Experiment will, Lfuppofe, fiffici- 
, ssib'd. in the, Alt Fi 
gure A BCD, and, having fill'd it with pure clear Water, expofe itto 
Sun beams 5 ene a piece of, very fine Venice Paper, apply it 
that is oppofite to the Sun, as sal te 
ee 
OE ES TT eee eee a 
yusedp rey oy oer po Ril y+ allel 
