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And this you may do without offendinge the ey, if you be wary. In the
beginning of your observation first hide the sonne with the crosse & so keep
him hidden with the orderly moving of your body & hand answerable to the
surge of the sea, & you bring him downe by litle & litle till you se only the
edge of the sonne; & if you see the other end of the crosse upon quick sight
close with the Horizon, it is well. Otherwise you must pull to or put from the
crosse untill you find that
beginning of your observation first hide the sonne with the crosse & so keep
him hidden with the orderly moving of your body & hand answerable to the
surge of the sea, & you bring him downe by litle & litle till you se only the
edge of the sonne; & if you see the other end of the crosse upon quick sight
close with the Horizon, it is well. Otherwise you must pull to or put from the
crosse untill you find that
The summe of all is this in taking altitudes by the staffe is
this. ffirst take the altitude close from the Horizon & that is called
the Apparent altitude. ffrom it abate two thinges that is the parallaxis of the staffe & the
surplus of the Horizon. The remaynder is the true hight
of the
this. ffirst take the altitude close from the Horizon & that is called
the Apparent altitude. ffrom it abate two thinges that is the parallaxis of the staffe & the
surplus of the Horizon. The remaynder is the true hight
of the
But if you take the higher edge of the sonne you must abate
16 minuts more & then you have the true altitude desired.
Examples of the premisses you shall have in the chapters of taking the altitudes of the pole.
There is yet is yet the altitude
16 minuts more & then you have the true altitude desired.
Examples of the premisses you shall have in the chapters of taking the altitudes of the pole.
There is yet is yet the altitude
If absolute exacteness were to be required then it is yet to be addded
to the altitude of the sonne two thinges, that is to say his parallaxis of altitude,
& angle of refraction caused by the ayre highest superficies of
the ayre: And to the altitude of the starre only the angle of
refraction. but because in your voyadge they amount not
ether one or both not to 3 [???] when most, I leave them for
other place & time to be
to the altitude of the sonne two thinges, that is to say his parallaxis of altitude,
& angle of refraction caused by the ayre highest superficies of
the ayre: And to the altitude of the starre only the angle of
refraction. but because in your voyadge they amount not
ether one or both not to 3 [???] when most, I leave them for
other place & time to be