140 
SECOND REPORT- 1832. 
papers in Zach's Correspondance as worthy the attention of 
the Astronomer. In vol. i. the effects of radiation from the 
thermometer bulb (which had been pointed out by Fourier, 
Annates de Chimie, vol. vi.) are insisted upon ; and the plan 
proposed by Fourier, namely to use two thermometers of 
which one has a blackened bulb and the other a clean one, 
and to apply to the indications of the latter a proportional 
part of the difference between the two, is recommended to 
observers. In vol. ii., Flaugerges proposes to inclose the 
thermometer in a case consisting of a bright inside surface, 
and a bright outside surface, with a thin lamina of some non¬ 
conducting substance between ; the form of the case to be such 
as will permit the free passage of air. He also observes, that 
probably the correction for temperature will depend on the 
hygrometer. It seems to me likely that these precautions 
might prevent many of the discordances that have been noticed. 
Among the various essays which, though less known, are well 
deserving of attention, may be mentioned, A theory of refrac¬ 
tion, by Schmidt; elaborate investigations by Plana, Littrow, 
Struve, and Schwerd, in their Observations ; terrestrial refrac¬ 
tions observed by Tralles (. Berlin Memoirs, 1804); refractions 
near the horizon observed by Mechain {Conn, des Temps, 1807), 
by Oriani (. Effemeridi di Milano, 1816), and by Foster {Phil. 
Trans . 1826); Lee’s remarks on atmospheric dispersion,—a va¬ 
luable paper {Phil. Trans . 1815): and Brinkley’s remarks on 
the observations of the same stars at Dublin and at Paramatta 
{Memoirs of the Astronomical Society, vol. ii. and Ast. JVach- 
richten, No. 78.). Rumker’s observations also (in his Prelimi¬ 
nary Catalogue) are intended, partly, for comparison with Eu¬ 
ropean observations, in order to obtain the amount of refrac¬ 
tion. 
While this subject was pursued at home and abroad, two 
discussions were going on, confined almost entirely to England. 
In the Memorie della Societa Italiana for 1805 and 1809, and 
the Berliner Jahrbuch for 1814, Piazzi, Chiminello and Calan- 
drelli conceived that they had found a sensible parallax in 
several stars. Bessel, however, could find no trace of it in 
Bradley’s observations. In the Transactions of the Royal 
Irish Academy, 1815, a paper appeared by Dr. Brinkley on 
the same subject; but the parallaxes whose existence he con¬ 
sidered to be established, differed considerably from those of 
Piazzi. In the Philosophical Transactions for 1817, Mr. Pond 
stated, that with the Greenwich circle no such parallax was 
discoverable. He proposed however that telescopes should 
be immoveably fixed to stone piers, for the purpose of observ- 
