REAPPEARANCE OF THE COMET OF 1812. 499 
computations more accurately. He proved beyond question that the positions 
marked out for comet Brooks were identical, at the time of observation, with 
those in which a comet would be found that was traveling in the ellipse computed 
by Encke. He went further, using the new orbit of the French astronomers, 
and proving that the comet was observed in the exact position where it should 
have been found according to the orbit computed seventy years ago. 
There is, therefore, no shadow of a doubt that our eyes behold the long ex- 
pected comet of 18 1 2. Its perihelion passage will take place on the 25th of Jan- 
uary, 1884. It will then be about 60,000,000 miles distant from the earth, two- 
thirds the distance of the Sun. 
In 1812, the comet presented, when discovered in July, the appearance of 
an irregular nebulous mass, with the tail entirely wanting. In September, the 
nucleus was 5' in diameter, and the tail was 2° 17' in length. Though not very 
bright, it was distinctly visible to the naked eye, and was observed for ten 
weeks before it disappeared in the star depths. The returning comet, when first 
seen, presented similar elements. About the 23d of September, however, a re- 
markable and unexpected outburst occurred, the nucleus expanding into a con- 
fused circular nebulous patch of light, and the comet increasing many times in 
brilliancy in the course of two or three days. On the 23d, the nebulous mass 
was 2' in diameter; on the 25th, it was 4' in diameter and shone with a lustre 
equaling a star of the seventh magnitude. The activity of the display is almost 
unparalled in cometic history, and is especially noteworthy on account of the 
comet's great distance from the Sun at the present time. Since this curious out- 
burst, the comet has been a well behaved member of the family, but it is impossi- 
ble to predict what vagary it may next indulge in. 
The comet of 181 2 may now be seen in the evening in the northwest in a 
telescope of moderate power, and is said to be visible in a good opera-glass. In 
a few weeks it will be easily perceptible to the unassisted eye, and when the year 
1884 makes its advent, it will be near its culminating point. It will not equal 
the superb comet of 1882 in size or brilliancy, but it will be visible in the evening 
sky and will be so much more convenient to observe that there will be compen- 
sation in its lessened splendor. 
It is an astronomical triumph, that with the inadequate means at command 
for computing an ephemeris, an astronomer seventy years ago was able to predict 
nearly the exact time for this comet's return. Our ancient friend is winging its 
swift flight toward us, and before long our eyes will be gladdened by a sight of 
its face after a long travel of threescore years and ten, when almost every eye 
that noted its first appearance has ceased to behold the shining picture that 
nightly arches over the earth. 
There are several comets with a computed period of from seventy to seventy- 
five years. Halley's comet with a period of seventy-five years is the only one of 
them that has made more than one return. Its last appearance was in 1835, and 
it is next expected in 191 1. The comet of 18 12 with a period of seventy-one years 
