A Table of the Sun's femi-diurnal Arches, or Times The SUN's Declination North. 77788 43 7 47 7 7 55 7 59 51 7 55 7888 7 53 7 58 33455 31 37 O 8 5 52 8 4 8 9 8 18 8 24 8 30 8 36 By thefe Tables the Times of the Sun's Rifing and Setting may be found, in any Part of the Kingdom of Great-Britain or Ireland, after the following Manner: Where the Latitude of the Place is known, take the Sun's Declination our of the Table, on the Noon of the Day you defire to know the Time of his Rifing and Setting; and with it, according as it is either North or South, enter thefe Tables in the Left Left-hand Column, under the Word Degrees; then look the Latitude of the Place in the Top of the Table; and in that Column, against the Sun's Declination, will be found the Time of his vifible half Duration above the Horizon, er Time of his Setting, correct by Refraction; then fubtract the Time of his Setting from 12 Hours, the Remainder will be the Time of his Rifag; double the Time of his Setting, the A Table of the Sun's femi-diurnal Arches, or Times the Sum will be the Length of the Day; and double the Time of his Rifing, the Sum will be the Length of the Night. But if the Latitude of the Place, and Declination of the Sun, confit of Degrees and Minutes, then a fmall Allowance muft be made for the Minutes in both Cafes, which may be done by a Perfon of an ordinary Capacity by a mental Proportion only. Thus, to find the Time of the Sun's Rifing and Setting at at Aberdeen in Scotland, on the Longeft Day; the Latitude of that Place is accounted 57 Degr. 7 Min. North, and the Sun's Declination 23 Deg. 28 Min. likewife North. By the fe you will find by the Table, that 5 Min. for the Sun's Declination, and 1 Min. for the Latitude of the Place, are both, to be added to 8 Hours 49 Min. the Time belonging to 57 Degr. of Latitude and 23 Degr. of North Declination, and the Sum will be 8 Hours 55 Min. the Time of his apparent Setting at Aberdeen, on the longeft Day, whofe Complement to 12 Hours, viz. 3 Hours 5 Min. will be the Time of his Rifing, &c. A Table of the Sun's Right-Afcenfion in Time, the greatest The time of the fouthing or meridian tranfits of the fixed ftars in pa. 46, may be found thus. On the noon of the day, preceding the night in which you want to know the time of the fouthing of any of thofe ftars, find the Sun's place in the Ephemeris, and with it take out of the above table his right afcenfion in time; this you may do by inspection to a minute, which will be fufficient for your prefent purpose: Then from the right-afcenfion of the ftar in pa. 46, fubtract the right-afcenfion of the Sun, the remainder will be the estimate time of the ftar's fouthing, and will not differ from the true time above 2 or 3 minutes at most, which may be near enough for ordinary ufes. But when great exactness is required, reduce the Sun's place to this eftimate time, and with it find in the above table his right afcenfion to feconds, which being fubtracted from that of the ftar, the remainder will be the |