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could not help delivering his fentiments upon it as a duty he owed the public.

Mr. Jenkinfon faid, when he afferted that parliament had ever been of

one opinion refpecting the intercourse of the Weft-India islands, he did not mean there had been no debates upon them, but that the acts which had paffed were of the fame tendency.

ASTRONOM Y.

Apparent time.

77

OBSERVATIONS MADE AT CHISLEHURST, IN KENT, LONGITUDE 19 IN TIME EAST OF THE ROYAL OBSERVATORY AT GREENWICH, AND LATITUDE 51° 24' 33" NORTH. BY THE REV. FRANCIS WOLLASTON, L L. D. F. R. S. FROM THE PHILOSOPHICAL TRANSACTIONS,* ECI CLIPSE of the moon, July 30, 1776: obferved with a 3 feet achromatic telefcope, and a power magnifying 29 times (that is, a fingle eye-glafs belonging to the day-tube) the aperture of the telescope being reduced to 1 inches. The night very clear and ftill.

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h.

I I

II II The moon covers a fmall ftar near her fouth limb.

The ftar hangs on the limb, before it disappears.

11 28 17 She covers another ftar a little fouth of her centre. This vanishes inftantaneously.

covered.

12 43

10 28 15 Copernicus touched.

10 29 49

covered.

ro 31 22 Helicon (but 2.) covered.

10 37 9 Plato touched.

10 37 54+ covered. 10 38 55 Tycho touched.

10 39 39

10 40 25

10 55

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bifected.

covered.

10 43 16 Manilius covered.

10 46 51 Menelaus covered. 5 Dionyfius covered.

10 48

4 Cenforinus covered.

10 58 57 A point (Promontorium

acutum, I believe) touch-
ed.

o 21 A fpot between M. Fœcun

ditatis and M. Nectaris
touched.

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Thefe occultations were ob-
ferved with another power.
of the fame telescope;
which is ufually reckoned
100, and which I have
formerly fo called; but
which, on an accurate ex-
amination, really magni-
fies almoft 75 times.
The emerfions of thefe ftars

were not obferved.

。 I judge the beginning of the

emerfion to be about this time; but cannot be certain.

Grimaldus quitted by the fhadow.

12 48

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3 41 33,5 Beginning. I fufpect the

minute to be mistaken, and that it should be

3h. 40' 335. The first impreffion could not be 2, I believe not 1", before I obferved it.

5 25 24 End. An undulation on the fun's limb; but the obfervation pretty good.

Eclipfe of the moon November 23, 1779: obferved with the fame telefcope, magnifying 75 times. The aperture reduced to two inches. Night clear and frofty. No wind. Apparent time. h. 7 11

The beginning not afcer

tained.

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covered.

7 81 The eclipfe total. 46 23 Moon's edge begins to emerge. 851 14 Grimaldus begins.

8 52 I

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emerges.

A haze comes on.

2 23:: Kepler bifected. This not clearly feen. Plato begins to emerge.

9 11 41

9 12 35

9 13 46

emerges.

Tycho emerged.

The haze comes on again too much for the obfervation to be purfued any. farther.

Eclipfe of the fund Oct. 16, 1781: obferved with the fame telescope and magnifying power.

Apparent time.

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9 45 35 The beginning of the shadow, I believe.

47 20 Ahazinefs obfcures the moon.

9 50 55 Ariftarchus covered. 952 20 Kepler covered. So it is fet

down;

Apparent time.

h.

down; but I do not recollect what I meant by this; whether it might not be only the fpot in the centre, fo that it might more properly be called bifected. 957 57 Gaffendus covered. I fufpect the minute here; and that it fhould be 56' 57". 9 59 41 Heraclides covered. 10 1 42 Copernicus touched. 10 3 5 covered. 10 3 26 Helicon covered. 10 4 12 Bulialdus covered. 8 A haziness again. ΙΟ 8 57 Plato covered. 10 15 30 Manilius covered. 10 15 54 Tycho touched. 10 17 5:

10

covered. This doubt,

ful. JO 19 10 Menelaus covered. 10 21 38 Dionyfius covered. 10 22 40 Plinius covered. A hazinefs again. 1028 25 Cenforinus covered. 10 34 34 M. Crifium touched. 10 39 45 covered. 10 46 34 Total darknefs, as I judged it. At 10h. 41' the moon had and the grown reddish, eclipfed part become more vifible than before. After fome time, during the total dark nefs, the moon was barely to be feen. In general, about the centre, it was darker than towards the circumference, which was ill defined. About

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Apparent time.

h. 1. N

12 39 36 Heraclides emerged. 12 42 56 Helicon emerged. 12 45 52 Copernicus emerged entirely. 12 47 22 Plato begins to emerge. 12 47 58 emerges. 12 48 30 Tycho begins to emerge. 12 49 58 12 58 8 Manilius emerges. 13 1 40 Menelaus emerges. 13 3 18 Dionyfius emerges. 13 5 40 Plinius emerges.

emerges,

13 11 22 Cenforinus (but 2.) emerges. 13 16 35 M. Crifium begins to emerge. 13 20 53 emerges. 13 25 38 The fhadow quits the moon near Langrenus, between that and M. Crifium. The dufkinefs does not leave the moon till fome time afterwards, but I did not wait to obferve it. The moon was darker during the eclipfe than ufual; but the air was not clear enough for any occultations of stars to be obferved.

Tranfit of Mercury over the fun's difk Nov. 12, 1782: obferved with the fame telescope, and a power of 75 times. The aperture reduced to two inches.

Apparent time.

h. 7 77

2 51 49 First impreffion obferved. It could not be 2" fooner. 2 54 57 Thread of light completed; but feen through clouds. The planet feemed to hang on the fun's limb 30" at leaft.

4 6 Through a break in the clouds, of fhort duration, feemed to have quitted the fun; but indeed the clouds were very unfavourable the whole time.

Occultation of Saturn by the moon, h February 18, 1775 obferved with the fame telescope; and, I believe, the fame power, with the whole aperture of the object-glafs 3,6 inches; but, I perceive, I have not fet down thefe particulars. Y 2

Præc.

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Occultations of ftars by the moon: obferved with the fame telefcope, and a power of 75 times, with the whole aperture of the object-glass.

Apparent time.

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Eclipfes of Jupiter's fatellites: obferved with the fame telescope and power (that is, 75 times; called ufually 100) and whole aperture.

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Apparent time.

h. 1 17

11 33 14

11 51

8 28

16. 2 Sat.

9

I

Im. flying clouds; obfervation doubtful.

Im. good; unless the minute be mistaken.
Z Im. good.

o 13 Im. pretty good; air clear, but a cold in my
eyes rendered the observation not fatisfac-

tory...

Dec.

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1776.
Nov. 17. 3 Sat.

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10 45 48 Em. good.

73 48

9 38 48,5 Im.; a fcintillation for fome feconds before it quite difappeared.

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Em, good.

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Em. very good.

11 57 35

Em. pretty good.

10 13 13

Em.; clouds, but pretty good.

9 6 42

Em. good.

11 30 30

Em. good.

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July 21. 1 Sat. Aug. 29. 1 Sat. 30.4 Sat.

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Emerfion; windy; but good.
Em.

Em.; fatellite feen then, but not distinct for
fome time.

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ΜΑΤΗΕΜΑΤΙCS.

ANSWERS TO MATHEMATICAL QUESTIONS. 75. QUESTION (II. Oct.) answered by Mr. WILLIAM KAYE, of Wakefield. CONSTRUCTION.

L

ET BDF be the given circle, and A the given point without it. Draw AD through O, the center; and, from A, draw AT to touch the circle in T. Then, if X be required between A and Y, on AT defcribe a femi-circle AGT; in which apply TĠ, the fide of a fquare which is equal to the given plane: but if X be required beyond Y, erect TG perpendicular to AT, and equal to the fide of the fame fquare. Join AG, and, from A, as a center, with the radius AG, defcribe

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