γ

CII.

χ

0.0 2 Leonis 23 27 10.7 +1.3

-0.2
-0.2

a Leonis 22h 30m 248.9-88.0 -0.82 +0.5-32s.3 22h 29m 44$.9 +48m 50 s.5 10h 00m 34s.2 10h 49m 248.7 y Leonis 22 41 38.3 -6.2 -0.2 +0.7 -31.0 22 41 01.637 33.8 10 11 53.6 10 49 27.4 23 19 07.1 +0.5 +0.5 -32.0 23 18 35.4 10 49 25.0 +0.4 -32.3 23 26 39.9

8 04.5 10 57 27.4 10 49 22.9

The mean from the three stars has been adopted.

For the following observations on Dec. 8, Dec. 9, and Dec. 12, the azimuth error has been assumed zero, as it nearly results from the mean found on December 13, 14, and 15; the level error is the level error is — 2.8, as found on the 13th and the two following days. The difference in the values of A on Dec. 8, 9, and 12, is in maximo but 0.1.

Excluding the results from a Androm. and y Pegasi, the observed AR. of the moon becomes

12 37 38.2

0.0

a Andro. 11h 28m 36 s.9-11 s.3 0.0-2.0-18.3 11h 28m 22s.3+1h 09m 13s.9 0h 00m 49s.9
y Pegasi 11 33 42.8 -10.5 0.0-1.4 -1.2 11 33 29.7+1 04 06.5 0 05 42.3
CI.
0.0-0.8 -1.2 12 37 36.2

1h 09m 638.8

1 09 48.8 ?(1 09 53.8)

Moon seen through clouds.

Giving the result by y Pegasi the weight two, the observed AR of the moon results as above; it is, however, preferable to reject the result altogether, on account of the great difference in the results by the two stars.

& Arietis DI.

2 45 14.6

2 54 22.7

0.0 +1.5

27 Tauri

2 56 03.7

+1.8

A' Tauri

3 11 38.6

+4.3

Difference.

2h 19m 02s.9-48.3 0.0-18.4-18.4 2h 18m 55s.8 +26m 16 s.13h 03m 178.0 3h 29m 338.1
0.0 -1.4
-1.3 2 45 11.9
3 29 35.6
0.0 -1.7 -1.3 2 54 21.2 -09 09.3 3 38 48.7 3 29 39.4
0.0-1.7 -1.4 2 56 02.4 -10 50.5 3 40 29.1 3 29 38.6
0.0-1.7 -1.4 3 11 39.8 -26 27.9 3 56 04.1 3 29 36.2

♪ Arietis is nearer to the moon in reference to declination than any of the other stars, and since they differ considerably in their value for the C's sidereal time, it seemed to be preferable to combine the results from 7, 27, and A' Tauri into one, and take the mean between it and that obtained by & Arietis. E。 + 12h 44m 248.9.

December 13, 1853. Circle West.

=

The above data were used in three different forms: 1st, omitting Polaris; 2d, omitting Polaris The first hypothesis gave apparently the best

and 3 Urs. min.; and last, taking all the stars.

A preliminary discussion showed that the result from Polaris was accordant with the results from the other stars; the whole group gave the following normal equations :

Excluding y Draconis, we obtain from the mean of four stars the deduced AR of the moon as above.

1 The azimuthal deviation cannot be found from the above observations. The mean a has, therefore,

been used, as found on the 9th and 10th, viz: a = + 24′′.9.

RECAPITULATION OF THE DEDUCED SIDEREAL TIMES OF THE MOON'S LIMB.

The longitude is deduced from the above values by a method received from Prof. Peirce in 1851, an account of which is given in Coast Survey Report for 1858, Appendix No. 21, p. 186.

From the Greenwich observations1 we have the following corrections to the tabular places of the moon's right ascension, as given in the Greenwich Nautical Almanac:

The weights assigned to the moon culminations are approximations; the greater the number and the better the agreement of the results from the moon culminating stars the greater the weight. The result deduced for December 9 is unreliable, and has been rejected; the result for December 8 is not much better, but has been worked up along with the rest.

1 Astronomical and Magnetic and Meteorological Observations at the Royal Observatory, Greenwich. Volumes for 1853 and 1854. London, 1855 and 1856.