[408] January 23d 12h, mean time, Paris, corresponding with midnight between January 23rd and 24th in the civil reckoning of time,—which at Venice would be 20 minutes to 1 o’clock in the morning of January 24th,—the moon’s longitude was 19° 57′,3 and her latitude + 2° 0,7, while Jupiter’s longitude was 32° 12′,0 and his latitude—1° 4′,6; so that there was no conjunction on that day. On the other hand, January 24d 12h 59m 3s mean time, Venice, corresponding with 57 seconds to one o’clock in the morning of January 25th, the position of the two planets was as follows:—
| Moon. | Longitude | 32° 17′,3 | Latitude | + 2° 58′,3 |
| Jupiter. | Longitude,, | 32° 17′,3 | Latitude,, | — 1° 4′,3 |
that is to say, they were then in conjunction; their position in the heavens being near the star α Arietis. [↑]
[409] This can only be understood in a general sense, as meaning that it was somewhere about six o’clock in the morning. For at the time of the conjunction, the sun was more than 20° below the horizon; and as the dawn is not perceptible till the sun is about 18° from the horizon, they could not have possessed even this imperfect means of observing its general bearing, without the aid of the anomalous refraction. [↑]
[410] Want wy sagen gestadich op de vorrnoemde twee planeten dat se altemet malcanderen naerderden—for we looked constantly at the two planets aforesaid, (and saw) that, from time to time, they approached each other. This is very loosely expressed. The author meant to say that they looked from time to time, and saw the two planets constantly approach. [↑]
[411] The moon stood 3° 47′,7 above Jupiter. At the time of the conjunction, the declination of the latter planet was + 11° 17′,2; so that in 75° 45′ N. lat. it must have set 37° 20′ west of the northern meridian. And yet it was observed in 11° 15′ west, when in fact it was 2° 44′1, below the horizon! This is very remarkable. For, as is well known, the setting of even the brightest stars is not perceptible. They always vanish before they reach the horizon. The peculiar state of the atmosphere, which at noon of the same day had raised the sun’s disc nearly 4°, allowed a star to be observed which had set 1 hour and 48 minutes previously. [↑]
[412] The longitude of the conjunction was 32° 17′,3, or 2° 17′,3 of the sign of Taurus, with reference to the old division of the ecliptic; though, owing to the retrogression of the equinoctial points whereby Aries has taken the place of Taurus, the conjunction actually occurred in the former sign, as is stated in note 2 of the preceding page. [↑]
[413] Their clock having stopped, and a twelve-hours sand-glass being their only time-keeper, it would be too much to expect precision in their immediate determination of the time of observation. But, fortunately, by placing on record the moon’s azimuth at the time of the conjunction, they furnished the means of calculating the true time within very reasonable limits. The result shows that they were rather more than an hour slow, as it wanted 1 minute and 48 seconds of five o’clock. [↑]
[414] The moon’s bearing by compass being N. by E. (11° 15′ E.), and the variation of the compass 2 points (22° 30′) W., the moon’s azimuthal distance from the northern meridian was 11° 15′ W. From this datum Mr. Vogel has calculated the time of the observation, and makes it to be January 24d 16h 58m 12s mean time, or 4h 58m 12s after midnight on January 25th. The difference between this time and that of the conjunction at Venice (0h 59m 3s after midnight) is, of course, the [[148]]difference of longitude between the two places; it being 3h 59m 9s, or 59° 47′ E. And Venice being 12° 21′ 21″ E. from Greenwich, it results that “the house of safety”, at the north-eastern extremity of Novaya Zemlya, is in 72° 8′ long. E. of Greenwich, or 89° 48′ E. of Ferro; its latitude being 75° 45′ N.
As the moon’s bearing and the variation of the compass are both given only to the nearest point, there is a possibility of error to the extent of half a point, whereby the longitude might vary as much as 5°, or 20 minutes in time. But there is every reason for believing the variation, as stated, to be very nearly correct; or, if in error, it is in defect, which would have the effect of decreasing the eastern longitude. [↑]