4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 8 h 54 m. RA Note.-Twilight is considered to last until the Sun is 18° below (vert horizon, and to begin when the Sun reaches a similar point in the morni before sunrise. When the line on which this 18° is measured is shortest twilight will be the shortest, and vice versa. This causes the shortest t occur in the winter months in northern latitudes, and longest in summer. By an examination of the chart we find the measure of twilight, dar daylight of the 24 hours to be: June 21, Length of day....... Length of twilight... Jan. 1, Length of day.......... .8h. 54m. Length of twilight......1h. 45m. The remainder of the space will more than make the 24 hours, which refraction of light, which causes an increase in the apparent length of th also of duration of the twilights. This apparent error is greatest in t months, as the Sun then shines through a denser and deeper atmospheric en H.M.S.H. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH. MH.M 1 1W 7 39 4 29 4 52 7 28 4 39 4 44 9 22 7 25 4 42 4 401 5 43 7 19 4 48 4 36 7 3 5 5 4 24 5 40 Full Moon... 18 9 37 8 37 7 37 6 37 Last Quarter. The full-faced or black 26 11 1 10 1 9 1 8 1 type figures are P. M., all others 8 13 9 27 9 7 10 3 5 24 10 210 40 5 25 10 59 11 20 5 26 11 58 ev 6 5 27 mo. 1 5 28 12 59 57 5 29 5 30 2 54 19 4 59 117 7 25 5 1 2 28 724 7 21 5 7 7 2 7 14 sets. H.M.S.H. MH. MH. MH.MH.M H.M H.MH.MH.M H.M 32 1 Sa.. 12 13 38 Moon rises H. W. and N. Y. sets. Moon Moon H. W. Sun Sun rises Sun Sun rises and sets. Char les ton. H.M H.MH.MH.M H.MH.MH.MH.M 5 13 6 51 10 50 7 11 5 16 6 46 7 35 7 7 5 20 6 41 6 55 5 33 6 25 7 15 |