286 Mr. POND's Catalogue of Eighty-four B Cephei. 1812, Oct. 22, 24, 26, 29, 31,30,574 Mean of 10 30,574 Nov. 3, 4, 21, 22, Dec. 5 Dec. 8, 9, 13. 1813, Mar. 16,1 20, Apr. 1, 2, 3, 8, 14 30,343 Mean of 20 30,458 Aug. 11, 12, 13, 15, 16 17, 1930,985 Mean of 30 30,634 20, 22, 23 Aug. 24, 25, 26, 30, 31, Sept. 2. 30,894 Mean of 4,0 30,699 3, 4, 5, 6 This result is probably exact to a quarter of a second. a Ursa Major. 1812, June 13, 29, July 9, 10.31,500 Mean of 1031,500 15, 20, Aug. 14, Oct. 1, 2, 3 Oct. 4, 6, 14, 15, 18, 19, 20, 23, 31,596 Mean of 20 31,548 27, 28 This result seems to be extremely exact, and probably does not differ more than one-tenth of a second from the truth. a Cephei. 1812, Oct. 28, 29, 31, Nov. 312,484 Mean of 10 12,484 21, 22, Dec. 5, 8, 9, 13 1813, Mar. 20, Apr. 1, 3, 8, 12, Aug. 11, 12, 13, 15, 16 12,735 Mean of 20 12,610 Aug. 17, 19, 20, 21, 22, 23, 2412,435 Mean of 30 12,551 25, 30, 31 Sept. 2, 3, 4, 5, 6, 7, 8, 9, 10, 12,228 Mean of 40 12,470 14 Exact to a quarter of a second. a Cassiop. 1812, June 17, 22, 28, July 6,22,839 Mean of 10 22,839 7, Oct. 26, 28, 29, 31, Nov. 3 Nov. 4, 5, 6, 7, 19, 20, 22, 28, 22,456 Mean of 20 22,647 29, Dec. 6 Dec. 7, 8, 9, 10. 1818, Jan. 9.522,59 Mean of 30 22,630 10, 16, 22, 24, Apr. 8 Apr. 9, 11, 17, May 26, 27, 28, 23,041 Mean of 40 22,726 31, June 7, 10, 12 This r } This result may, I think, be relied on, to a quarter of a second. r Ursa Major. 1812, June 22, Oct. 27, 28, Nov. 3, 5, 6, 21, 24, Dec. 6. 55,440 Mean of 10 55,440 1813, Mar. 17% 0808 Mar. 21, Apr. 1, 3, 4, 7, 8, 9, 10, 11, 12 Apr. 13, 14, 16, 17, 20, 26, 54.975 Mean of 20 55,207 2055,489 Mean of 30 55,301 May 31, June 1, 7, 8, 12, 2855,457 Me 25, 27, July 5, 6 May 22, 26, 28, 29 Mean of 40 55,340 | July 16, 20, 30, Aug. 7, 20, 31,54,952 Mean of 48 55,275 Sept. 12, 14 This result, like the last, is probably exact to a quarter of y Draconis. 1812, June 15, 16, 21, 23, 28, } 29, July 6, 7, 8, 9 3,845 Mean of 10 3,845 July 10, 11, 14, 17, 19, 20, 21, 22, 28, 29 3.779 Mean of 20 3.812 } | July 30, 31, Aug. 1, 3, 12, 13 3,182 Mean of 30 3,602 15, 17, 20, 21 Sept. 15, 16, 18, 19, 20, 21,|| } 3,604 Mean of 40 3,603 Oct. 9. 15, 21, 24, 26, 28, 293,651 Mean of 50 3,612 31, Nov. 3, 6 Nov. 8, 15, 19, 20, 21, 22, 23,1 Dec. 5, 6, 8 3,877 Mean of 60 3,656 This determination of y Draconis is extremely exact. Its zenith distance has also been determined, with equal accuracy, by 120 observations made with the zenith sector during the years 1811 and 1812: the mean of above 60 observations of 1811 do not differ more than one-tenth of a second from the mean of an equal number in 1812. Mean zenith distance beginning of 1813 by observations of 1811 By observations in 1812 Mean zen. distance by zenith sector N. P. D. by mural circle Sum or Co. latitude 2 17.8 " Ursa Major. 1812, June 11, 12, 13, 14, 15, 57,671 Mean of 10 57,671 17, 20, 20, 22, 23, 24 June 28, July 6, 7, 8, 9, 11, 15,58,069 Mean of 20 57,870 6, 18, 20, 28 mm Aug. 7, 15, 19, 20, 22, Sept. 16, 18, 20, 21, Oct. 4 Oct. 5, 7, 8, 24, 28, 30, Nov. 5, 6, 7, 14 nro: 480 C 58,138 Mean of 3° 57,966 58,000 Mean of 40 57,969 Nov. 18, 21, 23, Dec. 5, 8, 23:57,348 Mean of 50 57,845 1818, May 26, 28, 31, June 1 June 4, 7, 10, 11, 12, 16, 21,58,123 Mean of 60 57,891 22, 23, 25 June 26, 27, July 5, 6, 9, 16, 58,057 Mean of 70 57.915 18, 19, 20, 22 July 24, 27, 28, 29, 30, Aug. 83, 3, 12, 13, 16, 190-257,641 Mean of 80 57,881 This result is probably not inferior in precision to the last. a Persei. 1812, July 7, 9, 17, 20, 21, 28, 52,970 Mean of 10 59,970 Aug. 16, 17, Dec. 8, 12 Dec. 13, 14, 28. 1813, Jan. 8, 10, 11, 22, 24, 28, Feb. 5 Feb. 23, March 1, 4, 6, 7, 17, 19, Apr. 11, 12, 13 52,417 Mean of 20 52,693 52,468 Mean of 30 52,618 Apr. 14, 18, May 27, 28, June 352,824 Mean of 40 52,670 1, 19, 20, July 6, 15, 17 Exact to a quarter of a second. Capella. 1812, June 15, 26, 28, July 7, 20,987 Mean of 10 20,987 8, 9, 10, 14, 20, 23 July 28, 30, Aug. 13, 16, 17, Jan. 10, 11, 16, 22, 24, 27, 28, Mar. 2, 3, 5, 6, 7, 12, 17, 18, } Apr. 9, 10, 11, 12, 13, 14, 15, 21,124 Mean of 50 20,758 17, 18, 20 Apr. 21, May 28, 29, June 1, 19,537 Mean of 60 20,555 2, 20, July 4, 5, 6, 12 July 15, 16, 17, 22, 23, 25, 28, 29, 30, 31 20,258 Mean of 70 20,512 Aug. 3, 5, 6, 8, 9, 10, 11, 13, 20,061 Mean of 80 20,468 15, 17 One of the above series differs a second from the mean of the whole, a circumstance very unusual, but quite unconnected with error of division, I attribute it to want of sufficient care in reading off the microscopes. The mean result may, nevertheless, be depended upon to a quarter of a second. |