_Note_, The longest day at all places on the (North/South) side of the equator, is when the Sun is in the first point of (_Cancer_/_Capricorn_) Wherefore having rectified the globe for the latitude, find the time of Sun-rising and setting, and thence the length of the day and night, as in the last problem, according to the place of the Sun: Or, having rectified the globe for the latitude, bring the solstitial point of that hemisphere, to the East part of the horizon, and set the index to 12 at noon; then turning the globe about ’till the said solstitial point touches the Western side of the horizon, the number of hours from noon to the place where the index points (being counted according to the motion of the index) is the length of the longest day; the complement whereof to 24 hours, is the length of the shortest night, and the reverse gives the shortest day and the longest night. _Longest Day._ _Shor. N._ _Deg._ _Hours._ _Hours._ { 45 15½ 8½ Thus in Lat. { 51½ 16½ 7½ { 60 18½ 5½ If from the length of the longest day, you subtract 12 hours, the number of half hours remaining, will be the _Climate_: Thus that place where the longest day is 16½ hours, lies in the 9th _Climate_. And by the reverse, having the _Climate_, you have thereby the length of the longest day. PROB. XX. _To find in what Latitude the longest Day is, of any given length, less than 24 hours._ Bring the solstitial point to the meridian, and set the index to 12 at noon; then turn the globe Westward, ’till the index points at half the number of hours given; which being done, keep the globe from turning round its axis, and slide the meridian up or down in the notches, ’till the solstitial point comes to the horizon, then that elevation of the Pole will be the latitude. If the hours given be 16, the latitude is 49 degrees; if 20 hours, the latitude is 63¼ degrees. PROB. XXI. _A place being given in one of the_ Frigid Zones (_suppose the_ Northern) _to find what number of Days (of 24 hours each) the Sun doth constantly shine upon the same, how long he is absent, and also the first and last Day of his appearance._ Having rectified the globe according to the latitude, turn it about until some point in the first quadrant of the ecliptic (because the latitude is North) intersects the meridian in the North point of the horizon; and right against that point of the ecliptic on the horizon, stands the day of the month when the longest day begins.