The Montgomery advertiser., 1904-08-01
THE SKIES IN AUGUST
POSITION OF THE MOON, SUN AND
 PLANETS DURING THE MONTH.
Morning and Evening stars-Per- tmrbatfon of Planets and the Orbit of the Earth-The Con-
 stellatiOns,

Dditiu1OTe sun.
 In the course of the month of August the moon will present the following phases: Last quarter on the 4th, new on the 11th, first quarter on the l7th and full on the 18th. She will come nearest the earth on the 18th. and re- omstest from 1t on the 26th. At noon of the 1st of August the sun Is IS de- grees. minutes 32 seconds north of the equator, and in course of the montl. Will traverse an arc in declination of about g degree, AS seconds.
 The planet Mercury Is at first in Virgo. but will stay in Leo during the greater portion of the month. Venus shines as an evening star and sets be- tween ' and 8 o'clock. While for a brief time she will be in Cancer, she will enter Leo and stay there for the remainder of the month. After finger ing little while in Gemini the planet Mars will be in Cancer during the greater portion of the month, acting as morning star and rising between and o'clock. Jupiter is in Pisces and rises about o'clock in the evening. while Saturn, being in Capricornus, rises near 8 o'clock in the evening. The changes from a planets acting as morning star depend upon the rela- tive position of the planet in question, the earth and the sun, and as to the planets. Mercury and Venus, these changes depend especially upon their eastern and western elongations. When we see an inferior planet at a western elongation before sunrise It acts as a morning star, but when we see 1t at an eastern elongation after sunset it acts as an evening star Mer- cury is very seldom seen by the inexpe- rienced observer, and so 1t happens that to Venus is generally conceded the of being the morning and evening star. However. we extend the of morning and evening star to the superior planets. Mars. Jupi- ter and Saturn. the planets Uranus and Neptune being too distant to be seen with the unaided eye. When any of the superior planets shine during part of the evening we say that it acts as an evening star, and when we see it in the morning skies we speak of 1t as as a morning star. The info rior planets, of course, can be seen only for a comparatively short time and rather close to the horizon, while tn. superior planets can be seen in all parts of the heavens within the narrow belt of the zodiac.
 Although there is many a problem in pure mathematics and astronomy
 
 solute mathematical accuracy as we see in the propositions of Euclid. yet we can attain solution within any degree of accuracy short of absolute Among the celebrated problems that have exercised the mathematical geniuses there Is none more important than the problem of the three bodies" As to two attract ing bodies the problem admits of an easy solution, but as soon as an addt- tional body Is introduced into the sys- tenn the difficulty of a solution assumes formidable proportions. Each body now, instead of pursuing an ellipse will move along a curve of the utmost which the mathematician finds 1t exceedingly difficult, if not all together impossible, to follow. Sup posing, however. that one of the three bodies Is incomparably larger than either of the two others, then certain artifices can be employed which bring the problem within the power of hums.n ingenuity to solve. We first determine an approximate form from the track which one of the planets will pursue and from this we can obtain more accurate one. A further repetition of inc same process will exhibit an orbit still more close to that actually fol lowed, until at last. by what is known as successive approximation. 1t be- comes possible to determine the figure with a degree of accuracy correct foi all practical intents and purposes. lr the actual solar system there are also some other conditions which specially tend to the convenience of the math- ematical computer. It fortunately hap pens that all the orbits ir which the planets revolve He nearly in the same plane. An other advantage for the practical as tronomer lies in the fact that the move ments of all these planets take place in the same direction. By availine ourselves of these favorable condit' ions we have been enabled to discover with sufficient accuracy the in fluence which each planet is capable oi
 exercising on the orbits of the rest. The
 subject of planetary perturbation Is naturally one of the most difficult 1T
 the whole range of science as to attain ing to accurate results. although tho fact of these disturbances cannot but
 be obvious to anybody. Every ar
 tifce of the skilled mathematician i'
 employed to simplify the work, and the results obtained have amply Justified
 the labor that has been devoted to this important and interesting problem
 When precise examination of the plane
 tary orbits began to be made witt
 more perfect telescopes and then thu lapse of time had enhanced the value
 of early observation, 1t was found tha' the movements of the planets were not