Extract of a Letter to the Publisher from Mons. De Lisle, Astronomer Royal at Peters-Burgh, Containing His Observations of the Eclipses of Jupiter's Satellites from July 10th, 1726, to April 12th, 1728, Taken at That Place

VI. Extract of a Letter to the Publisher from Mons. De Lisle, Astronomer Royal at Petersburgh, containing his Observations of the Eclipses of Jupiter's Satellites from July 10th, 1726, to April 12th, 1728, taken at that Place. Petersburgh, July 25, 1728. SIR, I send you at present all the Observations of the Satellites of Jupiter that I have made here the two last times of his Appearance; and I don't question but there will be Number sufficient to settle the Difference of our Meridians, by comparing them with the Observations made in England. The following were made with common Telescopes of 13, 15, 20½, and 22 Foot; and are very good ones — | Year | Month | Date | Time | What Eclipse | Telescope | Notes | |------|-------|------|------|--------------|----------|-------| | 1726 | July | 10 | 12:47 | Im. of the 1st | 15 Foot | a little doubtful. | | | Aug. | 9 | 14:51 | Immer. — | 15 and 22 | doubtful near 15" | | | | 18 | 11:15 | Immer. — | 15 — | | | | | 11 | 15:52 | Immer. — | 20½ — | | | Sep. | 10 | 11 | 32:51 | Immer. — | 15 — | | | | | 11 | 32:56 | Immer. — | 20½ — | | | | | 22 | 16:13 | Immer. — | 2:15 — | | | Oct. | 19 | 12 | 21:46 | Em. — | 15 — | | | | | 28 | 8:47 | Em. — | 15 — | to some " | | Dec. | 6 | 7 | 11:18 | Em. — | 20½ — | somewhat doubtful. | | | | 10 | 30:31 | Em. — | 2:20½ — | exact. | | | | 10 | 30:38 | Em. — | 15 — | exact. | | | | 29 | 7:15 | Em. — | 20½ — | exact. | | | | 7 | 15:48 | Em. — | 15 — | exact. | | 1727 | Jan. | 2 | 10:59 | Immer. — | 3:15 — | Air foggy. | | | | 11 | 0:17 | Immer. — | 20½ — | Feb. | | D.H. | What Eclipse | Telescope | |------|--------------|-----------| | Feb. | Emmer. — 2 20 1/2 Foot. | | Aug. | Em. — 15 — | | | Em. — 2 20 1/2 exact. | | | Immer. — 3 22 — | | | Immer. — 1 22 — | | | Immer. — 2 22 — | | | Immer. — 1 22 — | | Sep. | Immer. — 1 22 — | | | Immer. — 2 22 — | | | Immer. — 1 22 — | | | Immer. — 2 22 — | | | Emmer. — 3 22 — | | | Immer. — 1 22 — | | Oct. | Immer. — 1 15 — | | Dec. | Em. — 1 22 — | | | Em. — 3 22 — | | 1728 | Jan. | Em. — 2 15 — | | | Em. — 1 13 — | | | Em. — 3 22 — | | | Em. — 1 22 — | | | Im. — 3 13 — | | | Em. — 1 22 — | | | Em. — 3 22 — | | Feb. | Em. — 1 22 — | | | Em. — 1 15 — | | | Em. — 2 22 — | | | Immer. — 3 22 — | | Mar. | Em. — 1 13 and 15 | | Apr. | Immer. — 3 15 — | | | Em. — 3 15 — | I am, &c. De Lisle. FINIS.