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OPERATION VI. How to make this Vertical South Dial by the Globe for the Elvation of London.
The second Way.
DEscribe a Blinde Circle of what bigness you please with a* 1.1 Diameter throu' it, and placing your String on the East or West Poynt of the Globe as before, measure (by your Bead or Compasses in any great Circle) the distance between the Zenith and each Intersection of the said String with the Hour Circles, and you will have the Degrees of every Hour from 12 a Clock, as the before mentioned Seventh Scheme shows you; so that by the help of your Sector (or of any Line of Chords or Quadrant) you may mark them successively in your Blind Circle on both sides of the Diameter, and then if you draw from the Center Lines throu' those marks, your Dial is finish't; for as to the Stile and Substilar, you need no other Instruction than what you had in the last Operation, which also directs you to the Demon∣stration, since the same serves both.