OBSERVATIONS OF WOLF’S, SWIFT'S, AND WINNECKE’S COMETS. 337 
1886, and the members are therefore merely referred to the paper 
just cited.. I may add that the published positions for 1886 rest 
mainly on the observations at the Cape of Good Hope and Windsor. 
Dr. von Haerdtl of the University of Innsbruck, investigated 
the elements of the comet’s motion for its various apparitions since 
its original discovery, and it will be interesting to the members to 
know that the observations at the Royal Observatory, Cape of 
Good Hope, and those made at Windsor, and published in the 
Society’s Journal are characterized by him as “two magnificent and 
beautiful series.” One of the useful results from Dr. von Haerdtl’s 
investigation is a new value of the mass of the giant planet Jupiter. 
At the return during the current year, the comet was first found by 
Spitaler of Vienna on March 18, with the help of Dr. von Haerdtl’s 
ephemeris. Jt was then in 30° N. declination and favourably 
situated for observation in the northern hemisphere. With the 
help of the same ephemeris I succeeded in picking up the comet 
on June 12, but as it was still well situated for northern observa- 
tories, local observations were not then made. The comet passed 
conjunction with the sun on July 7 ata distance of eleven millions 
of miles from our plauet, and on July 18 was picked up asa 
morning object and observed on all possible occasions from that. 
date to September 27. All my measures were made with a square 
bar-micrometer in a dark field, those for July 17 with the four 
and a half inch equatorial and all the others with the eight inch 
instrument. As Dr. von Haerdtl’s ephemeris is pretty exact, I 
have given the reductions of the comet’s apparent places to the 
earth’s centre instead of the usual parallax factors for the reduc- 
tion. I trust that the observations now submitted will prove as 
useful as those made at the previous return in 1886. I will con- 
clude my notice of this comet by drawing attention to an interest- 
ing observation which I made on September 27, asit throws some 
light on the extreme tenuity of cometary matter. On looking for 
the comet on the night of September 27—28 in the position 
; assigned to it in the ephemeris, I could not find it as a separate 
object, but a star of the 10th magnitude presented itself fringed 
V—Dec. 7, 1892. 
