The Birmingham age-herald., 1915-02-28

l April 20 it is approximately two hours, l on May 20, four hours and so on, reach- l ing 2 hours on February 19 and 2 hours 1 on March 6.
 If now we find the difference between l tie right ascension of the sun an any
 date and that. of any star, this differ
 cree will be the number of hours which will elapse between when the star was seen on the meridian anc when the sun I will be found there; as we know that the l sun is always on the meridian at noon, 1 tlie true time when the star was on the l meridian is at once known.
 l This brief description has been inserted 1 at the request of several different cor respondents; it is hoped that the reader will not be deterred from reading 1t by the slight reference to mathematics which 1t involves for the process is really very simple and easy indeed and the ability to read the time of night from the ever turning dial above us is always most pcasurable.
 illustrations of Finding Time at Night suppose that on the evening of March zl the observer saw the bright star Regu- rus due south of him, what would the t'ne be? Since on March 21 the right as tension of the sun is 0 hours and since that of Regulus is always 10 hours ; minutes the star will come to the me- rsoian 10 hours 3 minutes later than the
 
 E.jEutes p. fn
 As second illustration, let us inquire at what time the star at G, figure 1, will be seen due south of the observer on April and on April 20. The right as- cension of the sun on April IS one hour; that of the star is Il hours 10 minutes; the difference is 10 hours 10 minutes, and therefore when the star is seen due south on this date it will be 10 hours 10 minutes D. m. And on April 20 the right ascen- sion of the sun is two hours, the dif- ference is 3 hours 10 minutes and the time will be hours 10 minutes D. m This Illustrates the well known fact that the stdrs rise, come to the meridian and set just one hour earlier every TWO weeks
 After acquiring a little practice the observer will not usually wait until the bright star whose right ascension he knows has actually reached the merd- ian. Bearing in mind the right ascen- sion of the sun at the lime of the year, he might, perhaps estimate that the sta, was an hour to the left or to the right Of the meridian. The time found by men tally subtracting the right ascensions would then be one hour later than the true time in the first case and one hour earlier in the second. Soon he will find that mere glance at the heavens suf- fees to tell him the time. at least ap- proximately.
 All of the bright planets except Saturn aie now morning stars
 Mercury, which entered the morning | sky on February 21, reaches it's greatest distance from the sun on March 20 and 1 fc,' few days before and after this date | may be seen shining in the dawn. Iar to the south of the east point.
 Venus is still brilliant in the morning | skies, rising about two hours before sunrise throughout the month. At the | beginning of the month it is far below | the celestial equator. but 1t is movsng rapidly northward and its point of rising | on the horizon is continually approaching | the east point It will cross the equator atd then begin to rise north of east on | April 2s it will enter the evening sky i oa September 12.
 Mars is even nearer the sun than Ve- nus and Is therefore in a very dsad- vantageous position for observation Throughout the month it rises in the southeast about one hour before sun rise.
 Jupiter entered the morning sky on February 2i and is far too near the sun to be observed toward the beginning of the month, though by March 31 it Il rises nearly an hour before sunrise.
 All of these four bright planets. as .ell the planet Uranus. are now into one small region of the sky which would be by far the most