And now being able for all times either past, present, or to come, to give the Moons age, I think it good by a few Questions convenient for the Seamans practice, to make you understand the necessary rule thereof.

For the account of Tydes.

When you desire to know the time of Full Sea in any place at all such seasons as occasion shall require, you must first learn what Moon maketh a Full Sea in the same place, that is, upon what point of the Compass the Moon is, when it is Full Sea at the said place, you must also know what hour is appropriated to that point of the Compass as before is shewed:

For upon the Change day it will always be Full Sea in that place, at the same instant of time, by which considerations you must thus proceed for the search of Tydes.

Multiply the Moons age by 4, divide the product by 5, and to the Quotient adde the hour which maketh Full Sea in that place upon the Change day: if it exceed 12, cast away 12 as oft as you may, and then the hour of Full Sea remaineth: and for every 1 that resteth upon your Division, allow 12 minutes to be added to the hours, for 2, 24 minutes: for 3,36: and for 4,48 minutes: for more then 4 will never remain: and thus you may know your Tydes to a minute:

• Example: The Moon being 12 days old, I desire to know the time of Full Sea at London: First it is found by experience, that a Southwest and Northeast Moon makes Full Sea at London: next I consider that 3 of the Clock is the hour appropriated to that point of the Compass, (which number I keep in memory), then I multiply the Moons age, being 12 by 4, and that yieldeth 48, which being divided by 5, it givith the Quotient 9, and 3 remaineth: I adde the Quotient 9 to the 3 and it maketh 12 hours: and for the remaining number 3, I also adde 36 minutes so that I find when the Moon is 12 days old, it is 12 of the Clock and 36 minutes past, at the instant of the Full Sea at London: by this order you may at all places & times know the certainty of your Tydes at your pleasure.

But those that are not practiced in Arithmatick, may account these Tydes in this sort, knowing how many daies old the Moon is he must place the Moon upon that point of the Compass which maketh Full Sea at the place desired, & then reckoning from that point with the Sun according to the diurnal motion, must account to many points, and so many times 3 minutes, and there finding the Sun, he must consider what is the hour allowed to that point where he findeth the Sun, for that is the Hour of Full Sea.

• As for Example: The Moon being 12 daies old, I desire to know the hour of Full Sea at London, now finding by former experience, that a Southwest Moon maketh Full Sea at London, I Therefore place the Moon upon the point Southwest, then I account from the point Southwest 12 points, reckoning with the Sun according to the diurnal motion, Southwest and by West for the first point, West Southwest for the second, West by South for the third, West for the fourth point, and so forth, until I come to North, which is 12 points from the Southwest,
• and because the Moon moveth 3 minutes more than a point in every day, I therefore add 3 times twelve which make 36 minutes to the point North, at which place I find the Sun to be,
• and knowing that 12 of the clock is appropriated to the point North, I may therefore boldly say that at twelve of the Clock 26 minutes past, it is Full Sea at London, when the Moon is 12 days old, which 36 minutes are added, because the Moon hath moved 36 minutes more than 12 points in those 12 days, which is 1 point and 3 minutes for every day, as before.