Mr. Farey on Shooting Stars and Meteors. 183 
equal. Indeed for distances greater than 60°, such a correction 
is scarcely worth noticing, unless the scale of the projection be 
very great. 
If it were wished to construct a plate of this kind on a large 
scale, it might tend to ensure still greater accuracy in the part 
that relates to parallax, if in place of the sines of the apparent 
altitudes, we use the sines of the altitudes corrected for refrac- 
tion; attaching however still to these lines as their arguments 
the apparent altitudes only: so that no additional trouble will 
occur in the use of the plate; except that the correction for re- 
fraction should be applied to the distance before finding that of 
parallax. But after all, these niceties would seldom have any 
- sensible effect. The part for the correction of refraction might 
be brought to give the effect of the mean refraction to almost 
any degree of exactness, by slightly curving the three principal 
lines. 
The foregoing speculation, it is presumed, will he found to 
contain principles for constructing a simgle plate whereby all the 
cases may be solved with scarcely less facility or accuracy than the 
seventy plates of Margetts. A plate of the kind I intend shortly 
to publish; but previous to doing so, I shall endeavour to try of 
what further improvement it is susceptible. 
I am, sir, 
Your most obedient servant, 
July 16, 1821. Henry MEIKLE. 
XLI. On Suootine Stars, and Meteors which throw down 
MereEoro.itEs, as distinguished from fiery Appearances low 
in the Atmosphere, which have been supposed to proceed from 
terrestrial Exhalations, and to prognosticate [Vind and Rain, 
&e.; with Directions for observing Shooting Stars. By 
Mr. Joun Farry Sen. 
To Dr. Tiilloch. 
Sir, — I BEG to thank Dr. William Burney for his prompt and 
very obliging attention to my request, regarding Barometric Ob- 
servations on the second Monday of each Month; and hope that he 
and others of your ingenious Correspondents will persevere therein, 
and let slip no favourable opportunities of procuring such observa- 
tions to be simultaneously made, at as many points as_ possible 
on the open Coasts of the Ocean, at ascertained heights above 
high and low water marks on the days of observation. 
My best acknowledgements are also due to Dr. Burney, for 
his obliging notices of my Queries (in p. 346 of your last Vo- 
lume) in pages 22 and 127 of your late Numbers; from a iW 
u 
