VOYAGE TO THE 
The weather had for a long time been cloudy ; but on this night 
a clear sky presented to our view a comet of unusual magnitude and 
brilliancy, situated to the S. E. of the square formed by Ceti. The 
head had a bluish cast, and increased in lustre toward its nucleus, where 
indeed it was so bright, that with our small telescopes it appeared 
to be a star; but this was evidently a deception, as Mr. Ilerschell, 
mEo made some interesting and satisfactory observations on the same 
comet, found on turning his twenty feet reflector upon it, that the star- 
like appearance of the nucleus was only an illusion*. The tail extended 
between 9° and 10° of arc in a N. W. direction, and gradually increased 
in width from the nucleus till near its termination. We made a num- 
ber of measurements to ascertain its place, and continued them every 
night afterwards on which the comet appeared ; but as its orbit has 
been calculated from far more accurate observations, and ours were 
necessarily made with stars unequally affected by refraction, which 
involves a laborious reduction, besides the abstruse calculation for 
determining its orbit, I have not given them a place. 
On the following night we noticed distinctly the bifurcation of the 
tail represented in the Memoirs of the Astronomical Society. The 
branches were of unequal length, and the lower one diverged from the 
nucleus, at an angle of about 40° -f. 
On the 6th we made the Island of Mocha, on the coast of Chili, a 
place once celebrated as a resort of the Buccaneers, who anchored off* it 
for the supplies which in their days it furnished. Its condition was then 
certainly very different from the present: several Indian chiefs and 
a numerous population resided there, and it was well stocked with 
cattle, sheep, hogs, and poultry. At present it is entirely deserted, 
except by horses and hogs, both of which, Captain Hall states, are 
used as fresh stock by whaling ships in the Pacific. The Indians 
appear to have been generally very cordial with their visiters, ex- 
changing the produce of the island for cutlery and trinkets. Thev, 
however, apparently without provocation, attacked Sir Francis Drake, 
* See Memoir Ast. Soc. vol. ii. p. 2. 
f A sketch of this appearance is introduced at the end of the book. 
