Progress of Astronomy during the Year 1879. 4.59 
In October, 1850, Mr. Ferguson, of Washington, observed re- 
peatedly a star, which afterwards was missed and supposed to have 
been a planet, possibly an ultra-neptunian one. A search for it was 
made during the last months of 1851, but in vain. Professor C. H. 
F. Peters, however, finds that Mr. Ferguson had referred several 
transits to the first instead of to the second wire of the movable 
micrometer plate. The star observed was nothing but Lalande 
36613. This explanation was found to be correct by an exami- 
nation of the original observing book. Mr. F. had, for some 
unknown reason, in his reductions, changed all the correct obser- 
vations to correspond with the erroneous ones. 
8. Comets. 
The following comets were visible in 1879 :— 
a. Brorsen’s periodic comet was first seen by Tempel on 
January 14, and on February 26 by Tebbut. It passed the peri- 
helion on March 80, and was observed till the end of May. It 
was found more than a month earlier than Dr. Schulze’s ephemeris 
commenced. 
b. Tempel’s periodic comet was first seen by Tempel on April 
24, and was observed until the end of June. It passed the 
perihelion on May 7, according to Mr. Raoul Gautier’s elements. 
c. Swift found a pretty bright comet on June 16, which was 
independently discovered by Winnecke on June 21. It was 
observed till August 23. 
d. Palisa discovered a pretty bright comet on August 2], which 
was seen as late as October 12 (the date of the perihelion passage). 
e. Another comet was first seen by Hartwig on August 24. 
The last observation seems to be from September 14. 
The spectrum of Brorsen’s comet appeared this year very 
different from what it wasin 1868. It consisted of three bands, the 
central one the brightest, and the least refrangible one exceedingly 
faint. The wave-lengths as determined by Young, were 468-2, 
517-41], and 558+3. The abnormal character of the spectrum in 
1868 (which only one other comet, that of Borelly, c. 1877, has 
exhibited), has therefore disappeared, and the comet has now the 
ordinary spectrum.* 
* Young, N. xix. 559, Obs, III. 56, Christie N. xx. 5. 
