The Birmingham age-herald., 1914-03-08

, nish the occasion for several different kinds of astronomical observations. For example, a study of the faint light which renders the darkened surface of the moon visible leads us to d Knowledge of the constitution of the air surrounding the earth, for this faint Illumination is caused by rays from the sun which have passed through the dense layer of air about us and have been bent down, or re fracted," so that they enter the shadow cone. Sometimes this illumination is very feeble; during some eclipses of the moon the darkened portion has been absolutely invisible
 If, on the other hand, our air hap pens to be wet or dusty the red rays alone will pass through it.. To. an ob : server on the moon the earth would then appear as d black disc interposed between him and the sun, but the disc would be surrounded by narrow ring of brilliant red light. Usually the air about the earth is wet in some parts and dry in others and orsequentiy the moons disc has a mottled appearance.
 But the most important observa- tons of all are those which consist in observing the passage of the dark ened moon over the faint stars in the sky which lie in it's path. From these not only the size, distance and exact position of the moon can be calculated, but 1t can also be proved that if 1t has any atmosphere attallSthis must be less than one wo-thousandth part as den SC as our own. Such. observations will doubtless be made simultaneously by many of the leading observatories dur ing the present, eclipse.
 The Planets in March
 Mercury Is too close to the sun dur ing the present month to he observed. It passes from the evening to the morning sky on March 10, but will. not attain its greatest distance west of the sun and so become visible in the early morning until April T.
 Vents, which entered the evening sky on February Il. remains very near the sun throughout the month. On March 1t sets only IS minutes after sunset, but this interval Is increased to l9 minutes by the end of the month. The planet is tlius drawing steadily away from the sun's rays, but as it is still on the op- posite side of it's orbit from us its distance away is very great and i-s apparent mo- tion is Slow.
 Mars is high in the south, a little to the west of the meridian. and in excellent position for observation. It's eastward motion is now becoming much accelerat- ed; on March l the planet will be found at Y, Figure l. but on March 1t passes
 
 will have almost reached the star X. hay ing thus passed through almost the ex- act center Of the constellation of the I'wins.
 Saturn is moving slo~iy eastward in the constellation Taurus. We still see It's rings widely opened and it is there fore beautiful object iu the telescope This planet is steadily sinking in the evening sky and will not remain in a favorable position for observation longer than until the end of next May
 Jupiter is q morning star risine in the southeast about one hour and 4e minutes before sunrise on March 1.
 On March 2l, at six hours II minutes q. IT,, eastern standard time, the center of the sur will cross the celestial equator At this instant spring will begin. and this day and the preceding night will be of equal lengths
 ERIC DOOLITTLE.