8 
HEPORT—184/. 
groups is taken and laid down on a scale, in which the earth’s equatorial radios 13 
the unit. A circle described with a radius 0'2725 represents on the same scale ibe 
semidiameter of the moon : and the times of immersion and emersion of the starare 
given at once to the nearest minute by measurement on an accompanying scale; tke 
places of immersion and emersion upon the moon’s disc being represented by the same 
process. The same scale once drawn serves for all occultations. 
On Meteors, By Dr. Forstbr. 
On the Moons Atmosphere. By John Grooby. 
Whether the moon has an atmosphere or body of air similar to that which scf* 
rounds the earth, has long been a fertile subject of dispute among philosophers; 
some afCriuiog its existence, nud others as strcnuou-Hly denying It, Some who 
the negative side of the argument have urged, in defaice of their opinion, the coo- 
stant scremty of the nujou's auiface, always tindiaUirbed by donds or mpottrs,JDd 
even the smallest of the numerous spots or maculic which, crowd her surftev 
at all times equally visible. This certainly would be a very strong argument agiiii-'t 
the asaertiuus on which it is founded to be relied upon. Rot 
Inis does not appear to be the case, for nn the other hand there are tuany astnso- 
mers who nihrm that the moon’s surface w not always cquallyclcarand distinct. Anioi 
the existence of n lunar atmosphere has been denied, because the stars in an oewi- 
fetion, when just about to di.sa)ipear behind the body of the moon, retain their fall 
lustre ull they seem to touch the very edge, and then vauieh in a moment, «hith 
p snomeua JS urged) could not happen if the moon were encompas^sed with w 
atmo^pnerr. Here again the evidence of different astronomers is at variaDce, ow 
party oArming and tJic other denying the fact. 
A third urgumont against the existence of nn atmoMihcrc fand the last I 
n tice) 18 this: if (n jg affirmed) the moon were surrounded bvan acrao6phere.tliC“ 
and occultations ought to be diminished by means of ^ 
Pitnr«toi *10^ hence a celebrated French astronomer (in a memoir writhm 
d- f ^ f'ubject) lias ejidear'oun-d to demonstrate, that if such an a«o*- 
Kn r ♦ ‘ts horizontal refraction amounted to only 8”, there could 
biivi. Jn * VC qw of the sun. Many eminent astronomers concur with die oo* ^ 
osJ.iSST' • anything like refraction can exist, or has evertes 
the moon; others equally eminent assert that they have ob- 
ancqmvucal proofs of it. Both Halley and Euler speak of the eridat 
fon 3 Jimb In total and annular eclipses. The Utterio 
thit wh^ ^^1®'. happened in July 174?. be ohsen«l 
hnms ftC . i the sun resembled the moon in her quadrature 
evfi-v so ar crMreut appeared to be bent outwards bevond the circle in whicli 
lar “‘® ‘I'f ‘■‘^wprfheuded; and when the eclipse became ansa* 
dilatatiun WM also t.bsened by M. Poleck at Frankfort, and wi estimated by 
of lUi” luh'i IV"** sstronoiner obsen'ing in a solar eclipse a nUst^ 
does or'cJn cxittobservations, denies that any perceptible refractiw 
evidence it seems eirtremelv difficult to draw anything 
positive infr~en !3 nn*»r*^®**^*i’ ®ufhor su^ests, as a means of arriving at 
Oct 9th di^r^^n '1 carofel ob.‘K‘rvation of the approaching eclipse^ 
f ?v “r 'r horns, as Euler calls them; ^ 
micromotef^n,?^ the diameter of the sun with a double 
horns or vvhnf m rf 1 ^^ ooutart of the images cither to the point of one of tb«#« 
shall (if Vhe of the annulus the moment it is formed. ** 
the other imnirp 1 * the horn projected, or the annulus OTerl»|'pb>? 
nomeaoji will onlv imagined that this mode of observing the 
tion or not : but it will / whether there is anv perceptible projw- 
do more, for if we note the time between the completion of 
