inconceivable depth, they can hardly be considered as belonging to it, for the greater part retains the primitive character assigned to it by Simon Marius, namely, as resembling the light of a candle shining through horn. This very interesting object has apparently yielded less to the increase of optical power than any other celestial object which is visible to the naked eye, although the elder Her chel considered it as one of the nearest of the large nebula.

In the neighborhood of a Lyræ, within a circle surrounding that star of less than seven minutes diameter, upwards of thirty stars have been counted. The ring nebula of Lyra is shown more elongated than it is represented in the drawings of it in the Philosophical Transactions, with numerous points of light in the interior; the north preceding portion of the ring is considerably fainter than the rest. The minute double stars, mentioned by Lord Ross as difficult objects with his twenty-seven feet reflector, are seen in our telescope. Upon the whole, there is sufficient reason to be satisfied with the optical character of this instrument, particularly when we consider, that since it has been mounted, there have been but a very few hours when the state of the atmosphere would allow of using to advantage so high a power as 700, with the full aperture of the object glass.

PINGRÉ'S PREDICTED COMET OF 1848.

By George P. Bond, Assistant at the Cambridge Observatory.

The two comets numbered (17) in Prof. Peirce's catalogue of comets, which was published in the last volume of the American Almanac, were suspected by Pingré to be the same comet, at different returns, on account of the close similarity of their orbits. The returns in 1264 and 1556, give a period of about 292 years, so that the next return should be in 1848. Pingré's opinion seems to have been generally approved by geometers, and has been subjected to a very thorough and rigid examination, by Mr. Hind, of England, who has given coördinates, by which the computation of the quarter of the heavens, in which it must be looked for at different seasons of the year, may be readily performed, and from which the following table has been computed. In this table, the right ascension and declination are given, which the comet must have at the time of its discovery, provided this time is less than ninety days before the date of its perihelion passage, or less than eighty days after this date. The column headed ▲ contains the distance of the comet from the earth, and that headed contains the brilliancy of the comet, supposing the unit of brilliancy to correspond to the unit of distance from the sun and the earth. At its former returns, the comet approached exceeding near the earth, so that it is quite improbable that it will be seen again under as favorable circumstances for the magnificent display of its brilliancy.

Jan. 0 12.8-16 1.7 0.1 13.2-16 1.6 0.1 13.6-16 1.5 0.2 14.1-161.4 0.3

30 12.4 Feb. 9 12.0

171.3 0.3 14.3 171.3 0.4

18 1.2 0.3 14.4
19 1.0 0.4 14.5
19 0.9 0.5 14.4
19 0.7 0 9 14.1
16 0.6 1.2 13.4
10 0.5 1.8 12.0

181.1 0.5

191.0 0.5 19 0.8 0.8 20 0.6 1.5 18 0.5 2.2

13.7

120.4 3.2

30.6 1.2 10.4- 20.4 3.2

9.380.5 22

April 9

8.841.2 0.2

8.8

51.0 0.4

8.8

60.8 0.7

8.8

11 0.6 1.5

Sept. 6 10.8 12.8 0.0 11.0 12.7 0.0 11.2+22.5 0.1 11.4

1848. AR. Dec. ArAAR. Dec. Ar AR. Dec. 2AAR. Dec. Ar2AAR. Dec. 22 h. h.

J.

h.

h.

h.

014.7-16 1.4 0.3 15.4 -15 1.4 0.5 16.1-141.4 0.7 16.9-13 1.4 1.0

17.7-13

1015.0

171.3 0.4 15.7

2015.2 30 15.4

F. 915.5

1915.6 29 15.3

18 1.1 0.6 16.0
18 1.0 0.7 16.3
190.8 1.116.7
190.6 2.0 17.1

161.2 0.7 16.5
17 1.1 0.9 16.9
171.0 1.0 17.3
170.8 1.5 17.8
16 0.7 1.9 18.4
14 0.5 3.8 18.8

12 1.3 1.9 111.3 1.9

91.2 2.2

71.1 2.7

2012.011 0.2 18. 17.690.1 9.6 20.3+60.3 1.5 21.2 + 50.6 5.8 21.8+40.9 3.9

90.8 5.0

26 0.2 3.5 22.0

140.5 8.4 22.4

9 8.5

190.4 4.5.

7.4

41 0.2 2.4

0.9

50 0.1 13.8 23.1

25 0.4 1.3 23.0

15 0.7 6.0

02.0 0.2 12.7 01.8 0.4 13.111.6 0.8 13.6+ 11.4 1.5

21 1.2 0.9 9.5

28 1.0 2.1

8.8

39 0.7 6.0

9.6

33 0.9 5.0

82.0 0.210.9

1711.0

62.1 0.2 11.2

2711.3

52.1 0.2 11.5

IS. 611.5

32.2 0.2 11.8

1611.8

12.2 0.2 12.1+

22.0 0.212.43 1.8 0.4 12.7

AR. Dec. Ar22AR. Dec. Ar22AR. Dec. AAR. Dec. AA?
h.
h.

h.
14 1.5 1.3 20.4-151.4 1.0 21.1-16 .4 0.7
141.5 0.6

20 22.331.2 2.8 23.0+21.4 1.5 23.5+ 11.7 0 7 23.9

22AR. Dec. 2AAR. Dec. 2AAR Dec. A rAAR. Dec. Ar22 h.

h.

h.

J.

021.9

1022

20 22.5

30 22.8

151.5 0.4 22.8
13 1.6 0.4 23.0
111.7 0.3 23.3
81.8 0.3 23.5
71.9 0.2 23.8

29 23.7 M. 10 0.0

151.6 0.3 23.3
131.7 0.2 23.5
111.8 0.2 23.7
91.9 0.2 23.9
72.0 0.2 0.2
52.1 0.2 0.4

-17.4 0.5 22.5-17 1.4 0.3 23.1-18 1.5 0.2 23.6-17 1.6 0.2
151.6 0.2 23.7
13 1.7 0.2 23.9
0.1

0.0-171.6 0.1

15 1.7 0.1

20 0.3