The knowledge of the heavens and the earth made easy: or, the first principles of astronomy and geography. Explain'd by the use of globes and maps with a solution of the common problems by a plain scale and compasses as well as by the globe / Written several years since for the use of learners.

  • Watts, Isaac, 1674-1748.
Date:
1728
Catalogue details

Licence: Public Domain Mark

Credit: The knowledge of the heavens and the earth made easy: or, the first principles of astronomy and geography. Explain'd by the use of globes and maps with a solution of the common problems by a plain scale and compasses as well as by the globe / Written several years since for the use of learners. Source: Wellcome Collection.

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    Let the North Pole be raifed above the North part of the Horizon 51i Degrees which are numbred on the brazen Meridi¬ an, then let the Globe be placed at fuch a diftance as to make the Convexity inienfi- ble, and appear as a fiat or plane Surface, and let the Eye of the Spectator be juft level and oppofite to c, which reprefents the Eafl Point of the Horizon*, then the Globe and the Circles on it will appear nearly as represented in Figure III. The large Circle divided by every 5 De¬ grees reprefents the Meridian, the reft of the larger and the lefler Circles are there named, together with the North and South Poles. Z is the Zenith of London, Nthe Na¬ dir, H the South Point of the Horizon, O the North Point, C the Eafl and JVefl Points, S the Summer So If ice, W the Winter Sol- fiice, a the Eclipticks North Pole, e the E- clipticks SouthPole. The two Equinoctial Points are reprefented by C, fuppofing one to be on this Side, Pother on the oppofite Side of the Globe. If you would have the two Colures repre¬ fented here in this Figure, you muft fuppofe the Meridian to be the Solfticial Colure, and the Axis of the World to reprefent the Equinoctial Colure. Note, This Representation or Projection «f the Sphere in ftrait iines is ufually cal¬ led