The Deſeriptiom of the Hiurslintschrough P for che Hour- circles of 1, 2, 3,4, He.as they are numbred from the Meridian.Theſe are equal at the Pole, and at che Equa-tor, but unequally diſtant at the Horizon; thediſtance betu een the Meridian and che firſt Hourbeing not full 12 gr. the diſtance between thefifch and ſixth Hour about 18 gr. which inequa-lity being obſerved, if you ſuppoſe Right Linesdrawn from the Center C to the Interſections oftheſe Hour: eireles with the Horizön, the Line ſodraun ſhall be the Hour- lines here inquired.And then, if you can, imagine a Line drawnfrom the Center C, toward P the Pole of tlieWorld, and raiſed above che Meridian LineCN, ſo as the Angle PC N may be equal to theLatitude of che Place, this Right Line C P ſhallbe the Axis of the Style. And ſo you have bothStyle and Hour- lines ready drawn to your hand.But more particularly to our purpoſe. 25Theſe Hour · circles conſidered, with the Meri-260 2 dian and the Horizon, do make divers Triangles,63 45/57 47 PNA, P Na, PN 3, in which we have known,3062 firſt, che Right Angle at N, the North Interſe-ction of the Meridian and the Horizon; ſecond-ly the Side P N, the Ark of che Meridian be-78 45/7 J ween the Pole and the Horizon, which is always82 30080 25 equal to the Latitude of the Place; thirdly, the86 1585 13 Angles at the Pole, made by che Meridian and90 od ol the Hour-circles, the Angle NP 1 being 15 gr.5 NP 2 30 gr. each Hour 157. more than other,each half Hour 7 gr. 30 m. each quarter 3 gr. 45 im. as in the ſecond Columnof this Table. And theſe three being Known, we may find the Ares ofthe Horizon between the Meridian and the Hour- circles N 1, N 2, Nz,Cc. For, n 5 3

As the Sine of 90 gt.is to the Sine of the Latitude:Jo the Tangent f the Hour, öto the Tangent of the Hour- line from the Meridian.

Extend