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A Ship coming on the seventh of November, in the third Year after the Leap year, into the great South-Sea, thwart of the Coast of Peru, in Longitude 76 deg. The Pi∣lot desireth the Declination there at Noon in that Meridian.
| deg. | min. | |
| In the Meridian of London the Declination is | 19 | 08 South. |
| The Minutes Proportional added | 00 | 03 |
| In the Longitude 76 deg. the Declination | 19 | 11 West. |
| In the Longitude of 76 deg. East, the Declination is | 19 | 05 |
Two Ships being in Company, they parted at the Lands-end of England: The one Sails Eastwards, and cometh upon his Reckoning upon the 28th of September 180 Degrees on the other side the Globe of the Earth (being the first Year after the Leap-year) and by the foregoing Tables finds the Sun's Declination 5 deg. 57 min. The other Ship Sails Westwards, and meeteth the first Ship at the aforesaid place, by his Reckoning not the 28th, but on the 27th of September, and findeth the Decli∣nation in these Tables for that Day; so that they differ in the Time one Day, and in Declination 24 min. the which proceedeth from this cause: The first having Sailed against the Rising of the Sun 180 Degrees, hath shortned his time 12 Hours; the other hath Sailed with the Sun 180 Degrees, hath lengthned his time 12 Hours, and thereby hath one Night less than the first. Seeing then in 24 Hours increaseth 24 Minutes, he that Sailed Eastward must reckon 12 Minutes Declination less, and he that Sailed Westward 12 Minutes more than the Table doth shew; and so both of them shall keep one manner of Declination, to wit, 6 deg. 9 min.
| Alti∣tudes. | Sun. | Moon | Stars | Alti∣tudes. | Sun. | Moon | |
| min. | min. | min. | min. | min. | |||
| 0 | 34 | 33 | 30 | 18 | 06 | 06 | |
| 1 | 26 | 25 | 21 | 19 | 05 | 06 | |
| 2 | 20 | 20 | 15 | 20 | 04 | 05 | |
| 3 | 17 | 17 | 12 | 21 | 04 | 05 | |
| 4 | 15 | 15 | 11 | 22 | 03 | 04 | |
| 5 | 14 | 14 | 10 | 23 | 03 | 04 | |
| 6 | 13 | 13 | 00 | 24 | 03 | 04 | |
| 7 | 12 | 13 | 08 | 25 | 02 | 03 | |
| 8 | 11 | 12 | 07 | 26 | 02 | 03 | |
| 9 | 10 | 11 | 06 | 27 | 02 | 03 | |
| 10 | 10 | 11 | 05 | 28 | 02 | 02 | |
| 11 | 09 | 10 | 05 | 29 | 02 | 02 | |
| 12 | 09 | 09 | 04 | 30 | 01 | 02 | |
| 13 | 08 | 00 | 04 | 31 | 01 | 02 | |
| 14 | 08 | 08 | 03 | 32 | 01 | 01 | |
| 15 | 07 | 08 | 03 | 33 | 01 | 01 | |
| 16 | 07 | 07 | 02 | 34 | 01 | 01 | |
| 17 | 06 | 07 | 02 | 35 | 01 | 01 |
THe Refraction of the Sun, Moon and Stars, causeth them to appear higher above the Horizon than they are: Therefore the Refraction is alway•• to be sub∣stracted from the A ••••ude ob∣served, that the tr•• ••ltitude may be had.
As for Examp
The Sun's Meridian Altitude by Observation being 9 Degrees, I require the true Altitude.
| deg. | mi. | |
| Altitude by Observation | 9 | 00 |
| Refraction substract | 0 | 10 |
| The true Meridian Alti∣tude | 8 | 50 |
Of the Refraction of the Sun, A Dutch Ship being upon the Discovery of a North-East Passage to the East-India, was forced to Winter in Nova Zembla: the Mariners beheld the Sun 14 days sooner than he should by his De∣clination, and by Computation 5 Degrees under the Horizon; which is caused by the gross Vapours, and thickness of the Air neer the Horizon.