Navigation by the Sun and Moon

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Comprising the Sun's and Moon's course in the Zodiac, and the hours of moonrise and moonset, and at what point of the compass they rise and set, with other necessary things.

When the Sun has North declination, the further North you go the longer the days and the shorter the nights, and the further you travel South the shorter your days and the longer your nights. Contrariwise, when the Sun has South declination, the further North you go the shorter the days and the longer the nights, and the further you travel South the longer your days and the shorter your nights. And under the Equinoctial, the days and nights are all the same length no matter what declination the Sun has. Furthermore, the Sun, by its motion through the fourteen signs of the Zodiac throughout the year, causes the change in its declination. Now it is necessary for Seafarers to know in which declination the heavenly bodies take from Equinoctial to Equinoctial, and it is to be noted that as the Sun has declination, so does the Moon, and by their declination we know the time that they shine above the horizon.

Bearings for Rising and Setting at Seagate

Now the following rule is for Seagate, or any other place that has a Latitude or elevation of the Pole of 37 degrees. When the Sun or Moon are to be found on the cusp of the Maiden sign of the Zodiac, they rise due East, and set due West, and shine for 12 hours. On the cusp of the Messenger, they rise and set 12°30' further North which is near East by North and West by North and shine for 13 hours. On the cusp of the Smith, they rise and set 23° further North which is near East Northeast to West Northwest and shine for 13 hours 55 minutes. On the cusp of the Thief, they rise and set 29° further North which is from between East Northeast and Northeast by East to between West Northwest and Northwest by West, and shine for 14 hours 30 minutes. On the cusp of the Lover, it is as for the Thief. And on the cusp of the Warrior it is as it was for the Smith. And on the cusp of the King it is as it was for the Messenger. And on the cusp of the Mother, it is as it was for the Maiden. On the cusp of the Magician, they rise and set 12°30' further South which is near East by South and West by South and shine for 11 hours. On the cusp of the Wolf they rise and set 23° further South which is near East Southeast to West Southwest and shine for 10 hours 5 minutes. On the cusp of the Void, they rise and set 29° further South which is from between East Southeast and Southeast by east to between West Southwest and Southwest by west, and shine for 9 hours 30 minutes. And the Reaper is like the Void, and the Fool like the Wolf, and the Farmer like the Magician.

Now by this rule you shall know the rising and setting of the Sun and Moon forever. First the Sun is tied to the Zodiac by the time of the Year, so it rises and falls the same each year. For those who wish it easy, the chart below shows the progress of the Sun through the Zodiac, and also the length of the days and the compass bearing of sunrise and sunset at Seagate – for these vary with your location.

Rising and Setting at Seagate

Sign of the Zodiac	Date Sun is on cusp	Shining on cusp at Seagate (37°N)	Point of Rising	Point of Setting
Maiden	15 Seed Equinox	12 hours	East	West
Messenger	11 Blossom	13 hours	East by North	West by North
Smith	6 Meadow	13 hours 55 min	East Northeast	West Northwest
Thief	2 Heat	14 hours 30 min	Northeast by East	Northwest by West
Lover	28 Heat	14 hours 30 min	Northeast by East	Northwest by West
Warrior	24 Breeze	13 hours 55 min	East Northeast	West Northwest
King	19 Fruit	13 hours	East by North	West by North
Mother	15 Harvest Equinox	12 hours	East	West
Magician	11 Vintage	11 hours	East by South	West by South
Wolf	6 Frost	10 hours 5 min	East Southeast	West Southwest
Void	2 Snow	9 hours 30 min	Southeast by East	Southwest by West
Reaper	28 Snow	9 hours 30 min	Southeast by East	Southwest by West
Fool	24 Ice	10 hours 5 min	East Southeast	West Southwest
Farmer	19 Thaw	11 hours	East by South	West by South

The Moon in the Zodiac

Second the Moon is tied to the Zodiac by its cycle, and I have shown you before several times that it only takes 26 days for the Moon to move through the Zodiac and so it moves through each sign of the Zodiac in a little less than two days, or seven full signs in 13 days. But there is a further matter for the exact number, which is the Latitude of the Moon from the head or tail of the Dragon, and this means that the Moon moves faster or slower through the Zodiac, depending on whether it is near the Auge. And all this shows that it is sufficient to know that the Moon moves about half a sign each day, and from that and knowing any of the location of the Moon in the Zodiac, the bearing of the Moon rise or Moon set or the length of the Moon shine, being from the previous day, one can know all of these for the coming day.

And if you do not know of the Moon for the last several days, then it is enough to know how long since the last change or New Moon, for you will know which sign of the Zodiac the Sun dwells within, and for every day that the Moon is past new, the Moon will be half a sign to the East of the Sun. And this is more accurate for it takes a full 28 days for the Moon to change, being 26 days to encompass the Zodiac and 2 more to catch the Sun that has moved on. So if the Sun has just entered the sign of the Mother, and it is 10 days past the New Moon, then the Moon is 5 signs on, which is the start of the Fool, and thus it shines for 10 hours 5 minutes. And careful calculation with the Auge and many charts reveals it is 10 hours and 1 minute, but this is near enough for any Mariner.

Moon Zenith

It has been explained in the previous chapter on Tides how the Moon is due South at different times during the month, and a table was included called Tide Change or Moon Zenith. This table is also to be applied to find the Moon Zenith. For the Moon is at its Zenith at noon during its change and at midnight during the Full Moon. And it rises 53 minutes later each night, or between 40 and 66 minutes later, depending on if it is close to the Auge. And this chart is to be used to find when the Moon is at its Zenith, or eight parts of an hour can be added from the time of Zenith the previous night.

Moonrise and Moonset

Now when you want to know the time of Moon rise or Moon set, first find out what Zodiac sign the Moon is in, how long it shines, and when it is at its Zenith, as above. Then divide the length of shining into two equal parts, one before the Zenith and one after, and you have your Moon rise and Moon set. Continuing the example from above, if the Sun has just entered the sign of the Mother, and it is 10 days past the New Moon, then the Moon is 5 signs on, which is the start of the Fool, and thus it shines for 10 hours 5 minutes. Then it is at its Zenith at eight o'clock in the afternoon, and it rises 5 hours and 2 minutes before, and sets 5 hours and 2 minutes after, that is it rises just before 3 in the afternoon and sets after 1 in the morning. And it so happens that the Moon was just past the Auge, having delayed it by 47 minutes, so that it rises at 15:46 and sets at 1:48, but this error can be reduced by knowing the Moon Zenith one day earlier and not ten.

Six o'clock Shadow

And there is yet one thing which I wish Seafarers to reconsider, although a great number be expert in it. The sun being in the Smith or Thief or the Moon likewise, or any time when the Sun or Moon has North declination, they will set their compass before them, and when they see the Sun give an East shadow, they will say that it is six o'clock, and when the Sun is in the Thief it is not much more than half past three in the afternoon, and the more they are Southwards, the more they err. And similarly, when the Moon is in the Thief, and they see it give an East shadow by their compass, they will say the Moon is to the West, but they do not consider that the Thief comes so near our Zenith or vertical point, right over our heads, therefore they must judge East or West from the Pole Star to judge truly. Wherefore I also recommend the Equinoctial Dials for the exact truth.