By the Sun, or fixed Stars, being between the Zenith and the Equinoctial, the Latitude is thus found, in what part of the world soever you be.

• First, Place the Cross-Staff to your Eye, in such good sort as that there may grow no error by the disorderly using thereof, for unless the Center of your Staff, and the Center of your Sight do join together in your observation, it will be erroneous what you conclude thereby:
• Your Staff so ordered, then move the Transversary upon your Staff to and fro as occasion requireth, until at one and the same instant you may set by the upper edge of your Transversary, half the body of the Sun, or Stars, or that the lower edge of or end thereof so likewise touch the Horizon, at that place where it seemeth that the skie and the Seas are joyned, having special regard in this your observation, as that you hold the Transversary as directly uprightly as possible you may,
• and you must begin this observation somewhat before the Sun or Stars be at South, and continue the same so long as you perceive that they rise, for when they are at the biggest, then are they upon the Meridian, and then you have the Meridional altitude which you seek, at which time they will be due South from you if your Compass be be good and without variation,
• and then doth the Transversary shew upon the staff the degrees and minutes that the said body is from your Zenith, if the degrees of your instrument be numbered from the Zenith toward the Horizon: or else it sheweth the distance between the said body and the Horizon, if the degrees of your Instument be numbered from the Horizon, concluding 90 in the Zenith, as commonly Cross-Staffs are marked, which is not the easiest way:
• but if your staff be a accompted from the Horizon, then subtract the degrees of your observation from 90, and the remainder shewith the distance between your Zenith and the Sun or Stars, which is the number you must know: unto that number so known by your instrument, add the declination of the body by which you do observe, whether it be the Sun or ante Star, and that which cometh by the addition of those two numbers together, is the Poles height, or the Latitude of the place where you are:

• as for Example, In the year of our Lord 1621, the third day of March, the Sun being then between my Zenith and the Eqinoctial, I observed the Suns Meridional altitude from the Horizon to be 72 degrees and 20 minutes, but because I must know the distance of the Sun from my Zenith, I therefore subract 72 degrees 20 minutes from 90 degrees, and there remaineth 17 degrees 40 minutes, the distance of the Sun from my Zenith, to that distance I add the Suns declination for that day, which by my Regiment I find to be 43 minutes 2 degrees of South declination, and it amounteth unto 20 degrees 23 minutes, so much is the South Pole above the Horizon, and so much is my Zenith South from the Equinoctical, because the Sun having South declination, and being between me and the Equinoctical, therefore the necessity the Antarctick Pole must be above my Horizon.

When the Equinoctial is between your Zenith and the Sun or Stars the Altitude is thus found in all places.

• By your Instrument, as before is taught, you must seek the Meridional distance of the Sun or Stars from your Zenith: which being known, subtract the Declination of the Sun or Stars from the said distance, & the remaining number is the Poles height, or latitude which you seek:
• Example.
  The 20 of October 1625. I find by my Instrument that the Sun is 60 deg. 45 minutes from my Zenith at Noon, being then upon the Meridian, the Equator being then between my Zenith and the Sun:
  I also find by my Regiment that at that time the Sun had 13 deg. 57 min. of South Declination, because the Equinoctical is between me and the Sun, therefore I subtract the Suns declination from the observed distance, and there resteth 46 deg. 48 min. the latitude desired: and because the Sun hath the South declination, and the Equinoctical, being between me and the Sun, therefore I may conclude that the Pole Arctick is 46 deg. 48 min. above my Horizon so that my Zenith is so much toward the North from the Equator.

When your Zenith is between the Sun or Stars and the Equinoctial, the Latitude is thus found.

By your Instrument, as in the first example is shewed, you must observe the Meridional distance, of the Sun or Stars from your Zenith: you must also by your Regiment or other Tables search to know the Declination of that body which you observe, then subtract the observed distance from your Zenith out of the Declination, and the remaining number is the Latitude desired:

• Example. The Sun having 20 deg. of North declination, and being upon the Meridian is 5 deg. 9 min. from my Zenith, I therefore subtract 5 deg. 9 min from 20 deg. and there resteth 14 deg. 51 min. the Latitude desired: and because the Sun hath North Declination, my Zenith being between the Sun and the Equinoctical, therefore I conclude. That the North Pole is 14 deg. 51 min. above my Horizon.

How shall I know the true order of placing the Cross-Staff to mine eye, to avoid error in my observation ?

• To find the true placing of the Staff at your Eye, thereby to amend the Parallax, or false shadow of your body do thus:
• Take a staff having two crosses, a long Crosse which endeth in 30 degrees, and a short Cross which beginneth at 30 degrees where the long Cross endeth, put the long Cross upon his 30 degrees, and there make him fast: then put the short cross likewise upon his 30 degrees, there fasten him without moving:
• then set the end of your staff to your Eye, moving it from place to place about your Eye, until at one instant you may see the end of both Crosses, which when you find, remember that place and the standing of your body, for so must your Staff be placed, and your Body ordered in all your Observations.

Are these all the Rules that appertain to the finding of the Poles height ?

• Those that Travel far towards the North, under whose Horizon the Sun setteth not, shall sometime have occasion to seek the Latitude by the Sun, when the Sun is North from them, the Pole being then between the Sun and their Zenith.
• When such observations are made, you must by your Instrument seek the Suns height from the Horizon, subtract that height from his Declination, and the remaining number sheweth how far the Equinoctial is under the Horizon upon the point North for so much is the opposite part of the Equator above the Horizon upon the point South, subtract that Meridian Latitude of the Equinoctial from 90, and the remaining number is the Poles height desired:
• Example.
  The Sun having 22 degrees of North declination, his Altitude from the Horizon is observed to be 3 deg. 15 min. therefore subtracting 3 deg. 15 min. from 22 degrees, there rest 18 deg. 45 min. which is the distance of the Equinoctical from the Horizon, which being taken from 90, there resteth 71 deg. 15 min. the Poles elevation desired.

But you must know, that the Declination found in your Regiment is not the Declination which in this case you must use: for the Regiment sheweth the Suns Declination upon the Meridian or South point, in the place for whose Meridian the same was calculated, and not otherwise: Therefore it is necessary to know the Suns Declination at all times, and upon every point of the Compass:

• for I have been constrained in my Northwest Voyages, being within the Frozen Zone, to search the Latitude by the Sun, at such time as I could see the Sun, upon what point of the Compass soever, by reason of the Fogs and Mists that those Northern parts are subject unto:
• And there is consideration also to be had upon every difference of Lontitude for the Suns Declination, as I have by my experience found at my being in the Straits of Magilane, where I have found the Suns Declination to differ from my Regiment calculated for London, by so much as the Sun declineth in 5 hours, for so much is the difference between the Meridian of London, and the Meridian of Cape Froward, being in the midst of the said Straits.