Here followeth a very necessary Instrument for the knowledge of the Tydes, named An Horizontle Tyde-Table.

Of this Instrument, and his Parts. (Download the base)
This necessary Instrument for the young practicing Seamans use, named, a Horizontle Tyde-Table, whereby he may shift his Sun and Moon (as they term it) and know the time of his Tydes with ease and very certainly. (Besides the answering of may pleasant and necessary Questions used among Mariners) I have contrived into this method, only for the benefit of such young practicers in Navigation.

The first part of this Instrument is a a Sea Compass, divided into 32 points, or equal parts: the innermost circle of which Compass is divided into 24 hours, and every of those into 4 quarters, each quarter being 15 minutes, and against every point of the Compass those places are laid down, in which places it is Full Sea when the Moon cometh upon the same point, so that whatsoever is required as touching time, or the points of the Compass is there to be known.

The next movable circle upon this Compass, is limited to the Sun, upon whose Index the Sun is laid down, which Circle is divided into 30 equal parts or days, signifying the 30 days between Change and Change according to the Seamans account, so that whatsoever is demanded as touching the age of the Moon, is upon that Circle to be known,

The uppermost moveable Circle is applied to the Moon upon whose Index the Moon is laid down, which is to be placed either to the points and parts of the Compass, or to the time of her age, as the Question requireth: which considered, the use of this Instrument is largely manifested, by these Questions and theire Answers following.

How to know the hour of the Night by the Moon, being upon any point of the Compass by this Instrument.

1. Q. The Moon 10 days old, I demand what is a Clock when she is East Northeast ?

• 1. A. In this Question the Moons age and the point of the Compass is given, thereby to know the hour, I therefore place the Index of the Moon upon the point East Northeast, there keeping the same not to be moved, then because the Moon is 10 days old, I move the Index of the Sun until I bring the 10 day of the Moons age unto the Index of the Moon, and there I look by the Index of the Sun, and find upon the Compass that it is 12 of the Clock at noon and 30 minutes past, when the Moon is upon the point East Northeast, being 10 days old.

2. Q. The Moon being 12 days old I demand at what hour she will be upon the point S.S.E ?

• 2. A. In this Question the point of the Compass and Moons age is given as in the first, therefore I place the Index of the Moon upon the point S.S.E. And there holding it without moving, I turn the Index of the Sun, until the twelfth day of the Moons age come to the Index of the Moon, and then the Index of the Sun showeth me upon the Horizon the hour 8 therefore I say that 8 of the clock at night, the Moon was upon the point South Southeast.

And thus you may at all times know the hour of the night by the Moon, upon any point of the Compass, so that the Moons age be also had.

How by this Instruction, you may know at all times upon what point of the Compass the Moon is.

1. Q. When the Moon is 10 days old, upon what point of the Compass shall be at 9 of the Clock in the morning ?

• 1. A. In this Question the hour of the day and the Moons age is given, thereby to find upon what point of the Compass she is at the same time. I therefore place the Index of the Sun upon the Compass, at the hour 9 of the Clock in the morning being upon the point Southeast, then I turn the Index of the Moon untill I bring it to the 10 day of her age, and then I see upon the Compass, that the Moon is North and by East, and 15 minutes to the Eastwards, of the 9 of the Clock when she is 10 days old.

2. Q. When the Moon is 20 days old, upon what point of the Compass will she be at 2 of the Clock in the afternoon ?

• 2. A. I place the Index of the Sun upon the hour 2, noted in the Compass, there holding the same without moving, then I turn the Index of the Moon until I bring it unto the 20 day of her age, and there I see upon the Compass that she is Northeast and by North, and 15 minutes to the Northward, at 2 of the Clock in the afternoon, when she is 20 dayes old.

To find the Moons age by this Instrument.

1. Q. When the Moon is North at 7 of the Clock in the forenoon how old is she ?

• 1. A. In this Question the point of the Compass and the hour is given, for the finding of the Moons age: therefore I set the Index of the Sun upon the hour 7 in the forenoon, there holding it without moving, then I bring the Index of the Moon to the point North, and then upon the Circle containing the dayes of the Moons age, I see the Moon is 8 dayes, and about 18 hours old, when she is North at 7 of the Clock in the forenoon.

2. Q. When the Sun is East, and the Moon Southeast, how old is the Moon.

• 2. A. In this Question the points of the Compass are only given for the finding of the Moons age, therefore I put the Sun upon the point East, there holding him steady, then I put the Index of the Moon upon the point Southwest, and there I see that the Moon is 18 dayes and 19 hours old, when the Sun is East, and the moon Southwest.

After this order by the variety of these few Questions, you may frame unto your self many other pleasant and necessary Questions, which are very easily answered by this Instrument: and entering into the reasons of their Answers, you may very readily by a little practice, be able by memory to Answer all such Questions with ease.

How to know the time of your Tydes by this Instrument.

1. Q. When the Moon is 12 days old, I desire to know the time of full Sea at London.

• 1. A. To answer this Question, I first look through all the points of the Compass of my Instrument until I find where London is written, for when the Moon cometh upon that point of the Compass, it will then be full Sea at London: Therefore I place the Index of the Moon upon the same point, which I find to be Southwest or Northeast there holding the Index not to be moved, then I turn the Index of the Sun until I bring the 12th day of the Moons age to the Index of the Moon, and then the Index of the Sun sheweth me that at 12 of the Clock 36 minutes pst it is full sea at London, the Moon being 12 days old.

2. Q. The Moon being 21 days old, at what time is it Full Sea at Dartmouth.

• 2. A. I find upon my Instrument that Dartmouth is noted upon the points East and West, whereby I know that when the Moon is East or West, it is always Full Sea at Dartmouth: Therefore I place the Index of the Moon upon the point East, and there holding it without moving, I turn the Index of the Sun, until I bring the 21st day of the Moons age unto the Index of the Moon, and the Index of the Sun sheweth me upon the Compass, that at 10 of the clock and 48 minutes past, it is Full Sea at Dartmouth, when the Moon is 21 days old, and not only at Dartmouth, bur my Instrument sheweth me that at the same instant it is full Sea at Exmouth, Weymouth, Plymouth, Mounts Bay, at Linne, and at Humber: and thus with great facility the time of flowings and reflowings is most precisely known.