INDEX. 
Brinkley, Dr. J. remarks on the parallax of a Lyras, 471 — his 
examination of Mr. Pond’s reasoning respecting the com- 
parative merits of the Dublin and Greenwich observations, 
472, et seq. 
C 
Calcium, its indisposition to amalgamate with mercury in the 
voltaic circuit, 182. 
Cannon shots fired within one second of each other at 9 miles 
distance, how performed, 430. 
Carbonic acid , its effects on an explosive mixture submitted to 
the action of the platina sponge, 273. 
— — — oxide combines slowly with oxygen at common tempe- 
ratures by the action of the sponge, 26‘7 — effects of in mix- 
tures with hydrogen and oxygen, 271. 
Carburetted hydrogen, action of platina sponge on, in mixture 
with oxygen, 270— method of obtaining perfectly pure, 285. 
Catalogue of the fixed stars, agreement of that of Dublin with 
that of Greenwich, 51, disagreement of M. Bessel’s with 
both, and comparison with the two former, 80 — mean diffe- 
rence of those of Greenwich and Dublin, 64. 
■ — - — — of Piazzi, Phil. Trans. 1806, rejected by the author, 78. 
of Dublin, for 1823, compared with one computed 
from that of 1813, 84. 
— — of Palermo, ofWestbury, of Dublin, and of Green- 
wich compared, 84. 
— of double stars by South referred to, Part iii. 17. 
- — of ditto, Struve, ditto, Part iii. passim. 
- — of 145 new ditto, by Sir William Herschel, Part 
iii. passim. 
of 273 principal stars between the South Pole and the 
zenith of Cape Town, Cape of Good Hope, by the Rev. F. 
Fallows, 457, — description of the instruments used in, 458. 
Caterpillar , brain of, 10. — Plate II. 
Chronometers, used to ascertain the longitudes of Falmouth and 
Madeira, 360. 
— — effects of density of the air on the rates of, 372— 
explained, 408. — Some gain, some lose by rarefaction of the 
a\.r, 390. — Enquiry how far affected by ordinary changes in 
the air’s density in a given place, 393. 
Circle, altitude and azimuth, used by Mr. Fallows at the Cape- 
account of, 462. 
