154 Description and life of the

PROBLEM XXXI.

The time os the day at any oneplace being given, to find allthose places in which the funis then rifing, setting on themeridian, and where he is verti-cal ; likewise those places, in whichit is midnight, twilight, and dark-night, at the fame instant; aswell as thole places in which thetwilight is beginning and ending;and also to find the sun’s altitudeat any hour in the illuminated,and his deprestion in the obscure,hemisphere,

248. Rectify the globe to the day of themonth, art. 219. on the backside of thestrong brass meridian, and the fun’s decli-nation for that day, which is equal to theelevation of the pole, is given upon the gra-duated side of the brass meridian, by itscoincidence with the plane of the broad

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