A Collection of the Observations of the Lunar Eclipse, Sept. 8, 1736. Which Were Sent to the Royal Society

IV. A Collection of the Observations of the Lunar Eclipse, Sept. 8, 1736, which were sent to the Royal Society. 1. An Observation of an Eclipse of the Moon, made in Fleetstreet, London, by Mr. Geo. Graham, F. R. S. and by Mr. James Short of Edinburgh, F. R. S. on Sept. 8, 1736. Sept. 8, 1736. Apparent Time. | Event | H. M. S. | |-------------------------------|----------| | Beginning of the Eclipse | 12 58 0 | | The Shadow touched Grimaldi | 13 0 0 | | touched Kepler | 9 30 | | touched Copernicus | 17 10 | | touched the East Side of Tycho| 25 5 | | touched the East Side of Plato| 34 30 | | touched the East Side of Manilius| 36 40 | | touched the East Side of Mare Crisium| 56 20 | | Beginning of total Darkness | 14 3 45 | The Observation made with a 5½ Inches reflecting Telescope, magnifying about 38 times. 2. Eclipsis 2. Eclipsis Lunæ totalis observata Londini in Covent-Garden, Sept. 8, 1736. S.V. Telecopio 5 Ped. à J. Bevis, M.D. Temp. Appar. 12 53 25 Penumbra inficit Limbum Euro-boreum. Aëre Sereno. 54 25 Quæ nunc satis conspicua. Seren. 56 50 Umbra vera, quantum judico, Limbum attingit. Seren. 57 30 Umbra Grimaldum tangit. Seren. 13 00 25 Tegit Grimaldum. Satis Seren. 07 23 Intrat Mare Humorum, per tenues Nubes. Densissimæ deinde Nubes. 28 39 Mare Vaporum tangit umbra. Seren. 31 19 Lunæ pars obscurata subrutili quasi coloris cernitur. Valde Seren. 36 53 Limes Umbræ Manilium bissecat, & mare Serenitatis contingit. Valde Seren. 38 48 Mare Tranquillitatis tangit. Seren. 47 21 Tegitur Serenitatis Mare. Seren. 55 26 Tangit Mare Crisium. Seren. 58 05 Mare fœcunditatis obtegitur. Seren. 14 02 25 Immersio Lunæ totalis. Densissimæ Nubes superveniunt, nec Luna amplius conspicitur, priusquam 16 43 00 Mare Tranquillitatis, uti videtur, penitus retectum---per hiatum Nubium. 43 30 Iterum Nubes. 17 03 22 Discedente nube, Luna ab omni fuligine libera videtur. Hore Horologium per Altitudines Solis æquales Temporis vero aptabatur, ejusque Consensus cum Chronometro Dni. G. Graham, mediante optimo Horologio portatili notabatur. 3. Momenta Eclipseos Lunæ totalis, A. MDCXXXVI. die IX St. V. xx St. N. Septembris, mane Vitembergæ Saxonum observata, à J. F. Weidlero, R. S. S. &c. | Hor. | Min. | Sec. | Description | |------|------|------|-------------| | 1 | 36 | | Penumbra instar fumi vel nebulæ partem Lunæ orientalem subit. | | 1 | 50 | | Initium. | | 1 | 50 | 30 | Umbra appellit ad Grimaldum. | | 1 | 52 | | ———— attingit Galileum. | | 2 | 0 | | ———— attingit Keplerum. | | 2 | 1 | 30 | ———— totum tegit Keplerum. | | 2 | 7 | | Lunaris disce portio altius in umbram immersa clarius illa, quæ propter erat margini umbrae. | | 2 | 8 | | Umbra appellit ad Copernicum. | | 10 | 50 | | ———— tegit totum Copernicum. | | 16 | 10 | | ———— ad Tycho. | | 20 | | | Lunæ pars dimidia obscurata. | | 25 | | | Umbra ad mare serenitatis pertingit. | | 29 | 10 | | ———— ad Menelaum. | | 36 | 00 | | Tegitur totum mare serenitatis. Luna hoc tempore per umbram ruget instar prunæ. | | 45 | 30 | | Umbra ad mare Crisium appellit. | Hoc Hoc tempore circa mare Crisium umbrae margo introrsum curvatur. Et in tota Eclipsi umbrae peripheria aspera, variisque prominentiis distincta, & in extrema regione veluti tenui fumo circumdata certitetur. 2 50 00 Totum mare Crisium obumbratum. 53 00 Obscuratio totalis. Jam circiter tertia lunaris disce pars versus orientem obscurior appareat parte occidentali. 3 43 00 Umbra in medio obscurior, circa extrema dilutior videtur. 4 8 00 Luna nubibus involvitur. 4 44 00 Emeritio Lunæ ex umbra. 45 00 Umbra relinquit Grimaldum. Postea Lunam nubes absconderunt, ex quibus licet subinde iterum emergere, nebulæ tamen vel nubes rarior ita eam obumbrat, ut maculæ distingui non possint. Tandem nubibus densioribus tota Luna occultatur. Observatio Telescopio octo pedes Parisinos longo facta fuit. 4. An Observation of the Eclipse of the Moon, Sept. 8, 1736, made in Hudson's-Bay, by Capt. Christopher Middleton, F.R.S. Being in Hudson's-Bay, in the Latitude 55 Degrees 34 Minutes, North, and on the Meridian of the North-Bear-Island, which lies 30 Miles to the Westward of Charlton, I observ'd a total Eclipse of the Moon on Sept. 8, 1736. The Weather was very clear, but the Motion of the Sea render'd my Telescope useless, and I miss'd the Beginning. H. M. The total Immersion of the Moon's Body into the Shadow 8 22 by my Watch. The Emersion . . . . . . . . 10 8 by ditto. The End . . . . . . . . . . 11 16 by ditto. In order to rectify my Watch, and be certain of the true Time, I took three several Altitudes next Morning, and one in the Afternoon, by Mr. Hadley's and Mr. Smith's Quadrants; which (having made proper Allowances for the Refraction of the Atmosphere and the Height that I stood above the Surface of the Sea) were as follows: | Deg. Min. | Deg. Min. | |-----------|-----------| | First Altitude | 23 00 | | Latitude | 55 45 | Hence the true Time is 8 49 — The Time by my Watch 8 28 Watch too slow 0 21 — Second Second Altitude 25° 48' Latitude 55° 45' The true Time therefore is 9° 15' The Time by my Watch 8° 54' Watch too slow 0° 21' Third Altitude 26° 44' Latitude 55° 45' The true Time therefore is 9° 24' The Time by my Watch 9° 03' Watch too slow 0° 21' The Fourth Altitude taken in the Afternoon the same Day 21° 29' Latitude 55° 33' Hence the true Time is 3° 25' The Time by my Watch 3° 04' Watch too slow 0° 21' If 21 Minutes therefore be added to the times above-mention'd, for the Error of the Watch, we shall have the true times of the several Observations on the Meridian of the North-Bear-Island, as follows, viz. The total Immersion of the Moon's Body into the Shadow The Emerion The End This same Eclipse was observed Sept. 8, 1736, by Dr. Bevis at London, and he made the true Time of the total Immersion of the Moon's Body into the Shadow, 14 Hours, 2 Minutes, 25 Seconds; consequently the Difference of Longitude between London and North-Bear-Island in Hudson's-Bay, is 5 Hours, 19 Minutes, 25 Seconds, or 79 Degrees, 51 Minutes. IV. Eclipse Solaris observata Londini, Sept. 23, 1736. à J. Bevis, M. D. Temp. App. P. M. 4 12 35 Limbo Solis boreo filum parallelum PP decurrente, Limbus occidentalis attingit filum horarium HH. 12 42 Maculaparvula prope Limbum boreum ad filum obliquam primum i. pervenit. 13 01 Macula ad filum horarium HH. 13 20 Macula ad secundum filum obliquam 2. 14 45