l e m e . l i b r a r y . u t o r o n t o . c a

s t c 8 6 1

v e r . 1 . 0  ( 2 0 1 9 )



A DESCRIPTION OF
SOME PECVLIAR THINGES,
fit to bee considered, by such as intend to
practise the Art of Nauigation,
or Astronomy.


 THe Zenith   is an immaginary point
in the heauens, ouer our heades,
making right Angles with the Ho­
rizon, as the Equinoctiall maketh
with the Pole.

 The Nadir  is a pricke in the hea­
uens vnder our feet, making right Angles with the
Horizon vnder the earth, as the Zenith doth aboue;
and therefore is opposite vnto the Zenith.

 The declination of the Sunne,  is the Arke of a
Circle contained betwixt the Ecliptique and the E­
quinoctiall, making right Angles with the Equino­
ctiall.  But the declination of a Starre, is the Arke
of a Circle let fall from the Center of a Starre, Per­
pendicularly vnto the Equinoctiall.

 The Latitude  is the Arke of a Circle contained be­
twixt the Center of any Starre, and the Ecliptique
Line, making right Angles with the Ecliptique, and
counted either Northward, or Southward, according 
to the Situation of the Starre, whether it bee neerer
vnto the North or South Pole of the Ecliptique.

   The Latitude of a Towne or country,  is the height
of the Pole aboue the Horizon, or the distance be­
twixt the Zenith and the Equinoctiall.






 The Longitude of a Starre,  is that part of the Ec­
cliptique which is contained betwixt the Stars place
in the Ecliptique, and the beginning of Aries, coun­
ting them from Ariesaccording to the succession or
order of the Signes.

  The Longitude of a Towne or Countrey  are the
number of degrees, which are contained in the Equi­
noctiall, betwixt the Meridian that passeth ouer the 
Iles of Azores (from whence the beginning of Lon­
gitude is accounted) Eastwardes, and the Meridian
that passeth ouer the Towne or Countrey desired.

   The Altitude of the Sunne or Starre,  is the Arch
of a Circle contained betwixt the Center of the Sun,
or any Starre, and the Horizon.

 The Amplitude  is that part of the Horizon which
is betwixt the two East or West points, and the point
of the Compasse that the Sunne or any Starre doth
rise or set vpon.

 Azimuthes  are Circles, which meet together in
the Zenith, and Crosse the Horizon at right Angles
and serue to find the pointe of the Compasse, which
the Sunne is vpon at any houre of the day, or the
Asumeth of the Sunne or Starre, is a part of the Ho­
rizon contained betwixt the true East or West point, 
& that Azimuthe which passeth by the Center of the 
same Starre to the Horizon.

 The right ascention of a Starre,  is that part of the
Equinoctiall that riseth or setteth with the Starre, in
a right Spheare, or in an oblique Spheare, it is that
portion of the Equinoctiall, contained betwixt the
beginning of Aries, and that place of the Equinocti­
all, which passeth by the Meridian with the Center
of the Starre.






 The oblique ascention  is a part of the Equinocti­
all, contained betwixt the beginnning of Aries, and
that part of the Equinoctiall that riseth with the 
Center of a Starre, in an oblique Spheare.

   The difference ascensionall,  is the difference be­
twixt the right and oblique ascention: or it is the
number of degrees contained betwixt that place of
the Equinoctiall, that riseth with a Center of a Star,
and that place of the Equinoctiall that commeth vn­
to the Meridian with the Center of the same Starre.

   Almicanterahs,  are Circles drawne parallell vnto
the Horizon, one ouer another vntill you come vn­
to the Zenith: these are Circles that doe measure the 
eleuation of the Pole, or height of the Sun, Moone,
or Starres aboue the Horizon, which is called the
Almicanter of the Sunne, Moone or Star: the Arke
of the Sunne or Stars Almicanter, is a portion of an
Azimuthe contained betwixt that Almicanter which
passeth through the Center of the Starre, and the Ho­
rizon.