TV Beebe — The Cornet of IT 71. 
167 
a 
6 
a 
d 
April 6.5 
44° *26' 59-" 
0 
Mav 24.5 
114 ; O' 26*" 
38° 26' 45-' 
14.5 
54 11 59- 
25 4(1 .. 
June 1.5 
124 58 53- 
25 55 32- 
30.5 
76 59 4S- 
30 3 32- 
9.5 
134 45 54- 
.. 
Mav 8.5 
89 30 11- 
30 41 0* 
25.5 
150 57 33‘ 
16 18 16- 
16.5 
‘ 102 2 51- 
30 7 38* 
July 11.5 
163 36 9- 
10 3 51- 
The observations up to June 9 lie so nearly on the arc- of a great 
circle that it was found inconvenient to compute an orbit from four 
places. By the use of the normal places for April 6 and 30, and 
May 24, the following orbit was derived. 
Comet 1771. T April 19*12200 Paris. C — O 
7t 104" 18' 19' *93 \ ecliptic and April 30. 
& 28 11 51*86 - main equinox cos SJa, Jd 
(B) i 11 17 27*86 ) 1771*0 -f'*07 + f *40 
q> 75 38 21*85 log e 9*9862135 
log a 1*4576122 
log q 9*9524080 
An ephemeris computed from these elements and compared with 
the normal places gives the following residuals. 
C— O 
la 
Cw 

C- 
A a 
_o 
Ad 
April 6 O' 0" 
O' 
’ 0 r Mav 24 
+ O' 0’-2 
+ O' 0 ' 3 
14 + 27-9 
+ 
21-0 June 1 
+ l 27-5 
— 1 0-5 
30 + 1 
; + 
-4 9 
+ 4 61 
- 2 35-3 
Mav 8 — 47*0 
4-1 
5-7 25 
+ 10 3-0 
— 7 14-6 
16 —1 22-4 
! + 
12.7 July 11 
+ 16 37 4 
— 11 22-6 
From these residuals corrections to the ephemeris were obtained 
by the variation of the two geocentric distances for April 6 and May 
24. taken from the previous ephemeris. 
This method was preferred, though more tedious, because it 
requires elimination between only two normal equations : for when, 
as here, the differential coefficients cover only a short period, they 
vary so little as to render the elemination of six unknown quantities 
not wholly trustworthy. 
The elements, referred to the equator, are 
7T 105” 26 15 r *81 
Q' 9 34 7*59 
f 33 49 2*32 
The variation of 0, the geocentric longitude referred to the plane 
of the unchanged orbit as the fundamental plane, depends only on 
