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OPERATION III. How to find out any Place, the Longitude and Latitude be∣ing given.
THis Operation is not only usefull for the finding out of Towns express'd on the Globe, when you cannot guess whereabout they are situated, but also for the placing them truly in case they should chance not to be set down. Sup∣pose then Constantinople were the Town sought for, and that you found its Latitude to be 43 g. 5′. and Longitude 61 g. 46′. in some book or Geographical Table; I say supposing this, you have nothing to do, after having mounted your Bead (by the help of the devided Colurus) 43 g. 5′. above the Aequator, but to move your String on its Noose from the Pole to 61. 46. in the said Aequator, and Constantinople will be just under your Bead; and if (in case of Omission) it should not, you may then if you please marke it out your self, for that is its ex∣act place.
But by the way, if the Geographical Tables agree not with* 1.1 the Longitude of your Globe as telling you that (v. g.) Constan∣tinople has but 54 g. 36′, you are then to look from whence the said Tables begin, and finding their Commencement, suppose at Palma, and that Palma (according to the former Operation) has by your Globe 7 g. 10′. of Longitude, you must add this num∣ber to your Tables, and then you will agree.