;« The C O N T E N T $.

PS OB. XVII. To shew by the Globe, at one View,Length of the Days and Nights in any particu-lar Place, at all Times of the Year -7—108

Prob. XVIII. The Latitude of any Place, not ex-ceeding 66* Degrees, and the Day of the Month,being given ; find the Time of Sun-Rifing andSetting, the Length of the Day and Night 115

Prob. XlX. To find the Length of the Long tjl andShortest Day and Night in any given Place,, not

exceeding 66 5 Degrees of Latitude —■-116

Pr ob . XX. To find in what Latitude the Longest Day

is, of any given Length less than 24 Hours -117

Prob. XXI. A Place being given in one of theFrigid Zones (suppose the Northern) to findwhat Number of Days (of 24 Hours each) the Sundoth constantly Jhine upon the fame, how long he isabsent, and also the first and last Day of his Ap-pearance - — - — >> -— --- 118

Prob. XXII. To find in what Latitude the LongestDay is, of any given Length less than 182 Natural;

Days ■ ■ - -7 - . —: --- - -- 1 o

Prob. XXIII. The Day of the Month being given,to find when the Morning and Evening Twilightbegins and ends, in any Place upon the Globe —121Prob. XXIV. To find the Time when total Darknessceases, or when the Twilight continues from Sun-

fetting to Sun-ristng, in any given Place -123

Prob XXV. The Day of the Month being given, tofind those Places of the Frigid Zones, where the Sunbegins to Jhine constantly without setting ; and alsothose Places where he begins to be totally absent 124Prob. XXVI. The Latitude of the Sun’s Place, andhis Altitude, being given ; to find the Hour of theDay,and the Sun’s Azimuth from the Meridian 127Prob. XXVII. The Latitude, Hour of the Day,

- and the Sun’s Place being given ; to find the Sun’s

Altitude ->--- 128

Prob. XXVIII. The Latitude of the Place, and theDay of the Month being given ; to find the De-pression of the Sun below the Horizon , and his Azi-muth at any Hour of the Night ■129

Prob,