1833.]} - Analysis of Books. 381 
The results of our astronomer’s labour are not only most creditable to himself, 
but they prove how much may be effected by steady, well-instructed native assistants; 
for during the six months of Mr. TayLor’s deputation to Calcutta, to assist in 
measuring the Barrackpur Base, for the great Trigonometrical Survey, the four 
pundits attached to the observatory had entire possession of the transit, the mural, 
and the Satellite telescope, and very few cases occur in which there is room to note 
“‘ unaccountable,”’ against an entry in the register: at first only some malicious 
intruder was constantly giving annoyance by breaking the cross wires of the transit, 
as if to try the patience of the new master. 
In all computations of results, the observatory itself is made to furnish the data ; 
this also is a proper rule, for the climate, temperature, or clearness of the air have 
influences on refraction, and irradiation, which should not be trusted to estimated 
values, Thus, our author finds the mean diameter of the sun 16’ Or" 15: differing 
(how much ?) from European determinations. The effects of irradiation are 
closely connected with the sensibility of the eye. Differences of six or eight seconds 
will occur with different observers, and, Mr. Taytor says, it is no difficult matter 
in Dr. MasKketyne’s catalogues to discover when a new assistant came, 
from 
this circumstance. 
Following the tables of the sun’s diameter, we have a very full table of R. A. and 
N. P. D. of the sun, with the errors of the Tables computed for each observation, 
and from these the deduced obliquity of the ecliptic for 1st January 1831 is found 
From observations near the summer solstice = 23° 27’ 49”: 41, 
From do. ..-.. .. .. winter solstice = 23° 27’ 39” 98. 
or after correcting Goldingham’s latitude of the observatory, by — 0’ 71, 
The mean obliquity = 23° 27' 39-7: in the Naut. Alm. it is 23° 27/ ADU 1. 
But we have not space to enter into detail, and must confine ourselves to the 
heads of Mr. Taytor’s results. 
A table of the deduced error of the equinoctial points follows : and then we 
have the A. R. and N. P. D. of the several planets, including the Georgium Sidus, 
Towards the determination of the longitude, we have 84 comparisons of observed 
R.A. and N. P. D. of the moon, with her interpolated place from the Nautical 
Almanac ; one lunar eclipse ; and 21 eclipses of Jupiter’s Satellites. 
Mr. Taytor here also notices the different effects of irradiation upon different 
observers, which cause the semi-diameter of the moon to appear variable in its 
value, and necessitate an equal series of observations on both limbs to find the true 
passages of the moon’s centre*. 
No attempt is made to deduce the longitude from the lunar transits, because 
sufficient dependence cannot be placed on the lunar tables. The observations are 
however all compared with the interpolated place of the moon, from the Nautical 
Almanac, and the errors of the tables set forth: they vary from + 15 to — 17 
seconds in time. 
The mean of the 1st and 2nd Satellite observations gives the longitude from Green- 
wich, 5 hours, 21 minutes, 5.4 seconds, differing about a mile from Mr. GoLpiNG- 
HAm’s determination. Out of 51 observations of stars culminating with the moon, 
* In a series of lunar transits observed at Benares, with an 18-inch instrument, 
there was always a difference between the observed and calculated times of the 
moon's diameter passing the meridian, of nearly a second in time.—Orient. Mag. vii. 
p. 32, App. 
