Nov. 23, 1882] 
NATURE 
81 
THE following communications speak for themselves :— 
Columbia College, New Vork, November 4 
DEAR SIR,—I have received the inclosed communica- 
tion from Prof. Chandler, of Boston. The letter may 
interest your readers. J. K. KEES 
Harvard College Observatory, Cambridge, October 28 
DEAR S1R,—Your note of the 26th inst. was duly re- 
ceived. I respond cheerfully to your request, although as 
I have but a quarter of an hour at my disposal, I trust 
you will regard my answer as furnishing in a disconnected 
form the principal points in the results so far reached by 
me, and will bear in mind that I have not had an oppor- 
tunity to arrange them in a more formal shape. Of 
course the most interesting point in connection with this 
comet, astronomically, is the opportunity afforded to 
decide the question of the disturbance which a comet will 
experience in passing through the coronal regions in the 
close vicinity of the sun. Of all the comets which have 
passed near enough to be disturbed by this cause, this is 
the only one which has been observed on both sides of peri- 
helion. Not to mention others, the comets of 1680, 1843, 
and 1880, all of which present such close resemblance to 
Ingress of Gould’s Comet upon Sun, September 17, 1382. 
the present comet, as to have raised in some quarters the 
question whether they are not, in fact, returns of the same 
body, were observed, either insufficiently to decide this 
question of disturbance in the sun’s upper atmosphere, or 
were observed only on one side of perihelion. 
In the case of this comet, however, there will be avail- 
able a very extensive series of accurate observations at 
the Cape of Good Hope from September 8; almost 
* continuously up to within two hours of perihelion pas- 
sage, ceasing only with the ingress of the comet upon the 
sun’s disc, the instant of disappearance being accurately 
observed; an observation unparalleled in astronomical 
history, and of the greatest value. The comet was also 
observed at Rio Janeiro on September 11, and probably 
followed up to perihelion. 
I have also received from Dr. Gould a private letter 
dated September 15, on other astronomical matters, at 
the end of which he states incidentally that a brilliant 
comet had been visib!e there ‘‘ for more than a week, of 
which he had two observations, and was awaiting clear 
weather, in order to observe it in the meridian.” Thus 
in all probability he was the first to descry the comet, as, 
by a curious coincidence, he was the first to see the one, 
which so closely resembled it in 1880. 
After perihelion of course there exists, and will be 
accumulated hereafter, an abundant body of data to fix 
its orbit, after emergence from the coronal regions. Of 
all the observations before perihelion, we are in posses- 
sion as yet only of a position on September 8 at the Cape 
of Good Hope, the time of ingress upon the sun’s disc 
on September 17, and Mr. Common’s observations on 
September 17. The last, Mr. Common’s, I have not yet 
examined ; but from the others I have been led to con- 
clude that little if any disturbance could have been caused 
by resistance experienced in the sun’s atmosphere, so to 
call it, for the sake of convenience. 
The grounds of this conclusion are the following :— 
Taking all the observations available about a week ago, 
others have come to hand since, and verify the calcula- 
tion, although they could not be used in it, which were 
made since perihelion passage, z.c. from September 18 to 
October 20, I first computed an orbit from normal places, 
assuming the orbit to be a parabola, with the following 
results :— 
1882. 
7 = Sept. 17°22013 Greenwich M.T. 
m= 55 22 26'8 
=) CONES 882% 
2 = 345 53 404 
Za— TAT 5505.0 
log. g = 7°8915778 
The deviation of the middle place (c— 0) was +18'°8 in 
longitude and +8’°8 in latitude. It was very plain that 
the observations could not be satisfied better than this by 
any parabolic hypothesis. I accordingly computed an 
elliptical orbit as follows :— 
T = Sept. 17'2304 Greenwich M.T. 
T= 55 12 aua)) 
o= Q 22 72 See 
8 = 345 50 34°0( eee 
7) TA team O32 
log. g = 7°8835636 
@ = 0°9999700 
Notwithstanding the nearness to unity of the value of 
the eccentricity thus obtained, I believe that the ellipticity 
of the orbit is real, although the corresponding period is 
very long, something about 4000 years. Whether this is 
sO or not is not of great importance as regards my present 
purpose. If now we take the observation of September 8, 
nine days before perihelion, and compare it with the 
places which are assigned by these orbits, we find that 
the difference is only 2} seconds in right ascension and 
something over 1’ in declination. Thus the differences 
(Computation—Observation) are for the 
4a. Ad. 
Ellipse ... —2°5s. “pat 
Parabola +2°5s. +95" 
quantities which are certainly not larger than the un- 
certainty of the calculation, that is, not greater than we 
ought to expect even if the comet had been subjected to 
no chance of disturbance. 
Again, if we compute the place which would be assigned 
by the two orbits for the instant of ingress of the comet 
upon the sun on September 17, as observed at the 
Cape of Good Hope, and also the place of the 
sun, we have their relative positions as shown in 
the inclosed diagram, where the calculated places 
of the comet are indicated by the sign CG for the 
ellipse and parabola in red and black respectively, and 
the arrows indicate the direction and amount of the comet's 
motion in a quarter of an hour, as calculated by the 
orbits. It is significant that it would be necessary to 
assume a correction of only five or six minutes in either 
time of perihelion passage to bring the comet exactly upon 
