SCIENCE. 



[Vol. XIX. No. 486 



it gives positiveness to one's opinions and conduct, that one 

 more readily forms his final conclusions from first impres- 

 sions, and that a well disciplined mind might avert many 

 sad experiences, which an undisciplined mind is obliged to go 

 through, is undisputed. That the college graduate has many 

 edges to round off when he enters upon the struggle for ex- 

 istence is manifest. During his entire college course he has 

 only heard of the highest standards of the intellect and of 

 morality. Although he has been taught to deal with things 

 as they are, yet a large portion of his instruction lias been 

 devoted to things as they should be; and therefore when he 

 starts in life he must adjust himself to life as it is Whether 

 this is a fault in that the training is not held within the 

 limits of the practical may be an open question. But on the 

 other hand, that a college education has the tendency to 

 make one more humane, to broaden one's views of life, to 

 make one more liberal, to quicken one's perception, to lend 

 accuracy to the judgment, and insure more logical thinking, 

 cannot be denied. Feanklin A. Becher. 



THE SYSTEM OF ALGOL.' 



The steady advance of exploratory research in the system 

 of Algol promises to furnish one of the most curious and 

 instructive episodes in the history of science. Vague hy- 

 pothesis, determinate theory, and triumphant verification 

 have already played their logically sequent parts in the dis- 

 covery of the eclipsing satellite. Goodricke's conjecture, 

 however, had to wait nearly a century for Pickering's for- 

 mulization, while this was ratified within a decade by Vogel's 

 disclosure of the anticipated tell-tale spectroscopic effects. 



Progress has, indeed, of late notably quickened its pace; 

 and we may therefore hope for a prompt and effective appli- 

 cation of the Ithuriel-spear of adapted observation to the 

 latest creation of speculative intelligence in the lately organ- 

 ized department of "dark stars." Since Argelander's time 

 it has been tolerably evident that Algol had other attendants 

 besides the agent in producing its periodical eclipses. For 

 their recurrence was shown by him to be subject to minute 

 irregularities in point of time, and these irregularities are of 

 such a nature as to demand for their explanation the pres- 

 ence of at least one disturbing mass. A highly complex 

 piece of mechanism could plainly be seen to be at work ; yet the 

 penetration of its intricacies presented a task so formidable 

 that astronomers of, at any rate, the present generation 

 might well have despaired of its accomplishment. It has, 

 nevertheless, been undertaken by Dr. Chandler, and his 

 labors have been rewarded with an encouraging measure of 

 success.^ 



They have been necessarily of a more or less tentative 

 character, and their result must be looked upon as merely 

 provisional; but there is much reason to suppose that it at 

 least approximates to the truth. It is, moreover, perfectly 

 plain and straightforward ; there is nothing of the dbscurum 

 per obscurius about it; the consequences it involves are defi- 

 nite, and admit of definite verification. 



The new and enticing hypothesis now presented for the 

 consideration of astronomers is mainly founded upon certain 

 well-ascertained inequalities in Algol's period of variation. 

 These were shown by Dr. Chandler's discussion some little 

 time since ^ to be slowly compensatory. They are oscillatory, 

 not progressive. Consistently in advance of their due time 

 down to about the year 1804, the obscurations of the star 



■ From Knowledge for May. 



3 Astronomical Journal, Nos. 255, 256. 



3 Ibia,"vol. vll., pp. 165-183. 



then began to fall behind it, and the delay had accumulated 

 in 1843 to 165 minutes. A gradual process of restoration 

 thereupon set in, and the normal epoch was reached near 

 the beginning of 1873. It was quickly, however, transcended, 

 for acceleration is still going forward, and is likely to con- 

 tinue operative during some years to come. 



These irregularities are evidently comprised in a cycle con- 

 siderably exceeding one hundred years, and for that very 

 reason it is difficult to account for them on gravitational 

 principles; since a third body, exterior to the close pair, 

 should, in order to produce any marked purturbational effects, 

 revolve much nearer to them than would be consistent with 

 so long a period. Another mode of explanation is, accord- 

 ingly, resorted to by Dr. Chandler. The varying intervals 

 needed for the transmission of light from difi'erent parts of 

 a large orbit described by Algol and its dark satellite round 

 a remote primary, are, in his view, the fundamental cause 

 of the alternate anticipations and retardations in the occur- 

 rence of Algol's eclipses. They are, in fact, apparently shifted 

 backwards and forwards in time, just in the same way as are 

 the eclipses of Jupiter's satellites through the orbital move- 

 ment of the earth. Algol may, then, be regarded as the 

 solitary luminous number of a multiple combination of 

 opaque masses. The common centre of gravity, round 

 which the pair hitherto known revolves in a period of about 

 131 years, lies by the present hypothesis at a distance from it 

 just equal to that of Uranus from the sun. The path thus 

 traced out is, we are further informed, sensibly circular, and 

 its plane is inclined 20° to our line of vision. Obviously, 

 however, during the whole time occupied in travelling over 

 its remoter half, the light-minima of the star must be re- 

 corded somewhat later than if we saw them in the precise 

 order of their actual occurrence ; and this remoter half was. 

 swept over between the years 1804 and 1869, when the ob- 

 served phases were always in arrear of calculation. Now, 

 on the other hand, that the star is on tl'e hither side of its 

 orbit, the epochs of its eclipses are apparently anticipated, 

 and will not coincide with their true times until the passage 

 of the "ascending node," about 1934. The dimensions of 

 Algol's orbit, with its inclination, of course prescribe the 

 amplitude of the oscillations by which its periodicity appears 

 to be disturbed; and this " light equation," as we may call it, 

 proves to be 149 minutes. This should be the maximum ex- 

 tent, whether of acceleration or of retardation ; but in point of 

 fact, as we have seen, delay mounted up in 1843 to 165 mi- 

 nutes. Hence the theory cannot be said to represent the ob- 

 servations as satisfactorily as could be desired. The devia- 

 tions, indeed, are large enough to suggest to Dr. Chandler 

 further complications, the unravelment of which may chal- 

 lenge the utmost skill and patience of investigators. Mean- 

 time, a touchstone of the general truth of bis hypothesis will 

 soon be at hand; for it involves a cessation within the next 

 ten or twelve years, and a subsequent reversal of the shorten- 

 ing process at present affecting the star's period of luminous 

 change; and the fulfilment of this prediction will serve as a 

 hall-mark of its genuine quality. An additional test may 

 be derived from the spectrographic evidence. The velocity 

 of Algol in the large orbit attributed to it is 2.7 miles per 

 second; but of this, less than one-half, or about one mile 

 per second, is at present directed towards the earth. It con- 

 stitutes, however, a goodly proportion of the 2.3 miles of 

 continuous approach determined from the Potsdam plates; 

 but which should in the course of a score of years, if the 

 new theory be true, completely disappear, neutralized by the 

 altered direction of the star's orbital motion. It remains. 



