128

The Use of

viz. X at Night; which being done, theMeridian of the Globe stands in the true Meridian of the Places The Globe standing inthis Position, if you hang two Plummets atthe North and South Points of the WoodenHorizon, and draw a Line betwixt them,you’ll have a Meridian Line; which, if it beon a fixed Plane (as a Floor or Window'will be a Guide for placing the Globe dueNorth and South at any other Time,

Prob. XXVII. The Latitude, Hour of the

Day, and the Sun's Place being given,find the Sun's Altitude and Azimuth.

Rectify the Globe for the Latitude, theZenith, and the Sun’s Place; then the Num-ber of Degrees contained betwixt the Sun’sPlace and the Vertex, is the Sun’s Meridio-nal Zenith Distance; the Complement ofwhich, to 90 Degrees, is the Sun’s MeridianAltitude. If you turn the Globe about,until the Index points at any other givenHour, then bringing the Quadrant of Alti-tude to cut the Sun’s Place, you’ll have theSun’s Altitude at that Hour; and where theQuadrant cuts the Horizon, is the Sun’s

to

Azimuth at the fame Time. Thus ibfizythe20th at London, the Sun’s Meridian Alti-tude will be 61 ^ Degrees; and at i o o’Clockin the Morning, the Sun’s Altitude will be52 Degrees; and his Azimuth about 50 De-grees from the South Part of the Meridian.

• Prob.

Se

Ps

tuc

Po

Sui

kz

wil

qui

20 '

the

Ian

Pk

Ze

ft

Sui

the

an<

Ui

Ea

ant