March 1, 1889.] 



♦ KNOW^LEDGE ♦ 



lOo 



round the variable. This variable star, R Corona? Australis, is 

 also situated in a small nebula, and the nebula is variable also. 

 Moreover, there is another variable star, H Coronre Australis, 

 and two other nebate within 5' or 6' of are of this one. 

 U Geminorum, a very remarkable variable, with an irre- 

 gular period (it once increased three magnitudes in 24 hours), 

 ^vas observed by Baxendell to be nebulous at maximum. A 

 star near Nova Vulpeculre of 1G70, within 1' of arc of its 

 calculated place, was observed to be nebulous or ill-defined 

 by Hind, Talmage, and Baxendell. Of tj Argus, Nova 

 G'ygni 187G, and Nova Andromeda; 1885, there is no need 

 to speak. T Suurpii was situated apparently not in a 

 nebula (for M 80 Scorpii, though often called a nebula, is 

 I'eally a veiy condensed cluster of small stars) ; but never- 

 theless, its probable association with the cluster, and the 

 fact that there are at least two well-recogni.sed and one or 

 two suspected variable stars in the same field of view, is 

 woithy of notice. The variability of at least a dozen small 

 stars in or near the trapezium in the great nebula of Orion, 

 and of certain parts of the nebula itself, is more than sus- 

 pected, while Nos. 654, 709, and 822 of Bond's " Catalogue 

 of Stars in the Nebula " are recognised variables. 



THE TOTAL SOLAR ECLIPSE OF 1889, 

 JANUARY 1. 



By a. C. Ranyakd. 



J^ GREAT number of American astronomers, 

 both amateur and juofessional, journeyed 

 to the State of California to place them- 

 selves on the first of Januai-y of this year 

 within the path swept out by the moon's 

 total shadow. Within this narrow track 

 of shadow during the minute that the total 

 eclipse lasted observers were able to see the 

 faint objects in the sun's neighbourhood which are usually 

 hidden from our sight by the dust and sm.all light-dispersing 

 particles which float in the earth's atmosphere. Under 

 ordinary circumstances this dust is so brightly illuminated 

 by the sun's light that it blots out the stars and the faint 

 Hght of the solar corona as if a veil were drawn across the 

 heavens — a veil not thick enough to be opaque, but through 

 which only brighter objects can be seen, the sun quite 

 clearly, the midday moon subdued in light, and very occa- 

 sionally a brilliant comet, and Venus at her brightest ; but 

 otherwise the blue veil of sky light with whicli everyone 

 is so familiar blots out, or rather drowns with its own 

 brightness, the fainter light of the stars and milky way, 

 which shine behind it just as steadily as at night. 



During the precious moments of totality the direct light of 

 the sun, which ordinarily illuminates this blue curtain, is cut 

 oil' by the body of the moon, and the dust- veil becomes trans- 

 parent, so that for a few moments we can look through it 

 and seethe comparatively faint objects about the sun, which, 

 one need hardly explain, can never bo studied at night, as 

 they rise and set with the sun. 



During the darkest total eclipse a little light finds its way 

 Ironi obji'cts on the horizon, outside the shadow area, to the 

 ihist (loatiug in the air within the moon's .shadow; and even 

 I his light is sulliL'iout to faintly illuminate the dust- veil, so 

 that it blots out most stars below the third magnitude, 

 though sharp eyes have occasionally seen stirs of the fourth 

 magnitude when the observer know ju.st where to look for 

 them; but we may be suie that it is only the brighter 

 surroundings of the sun that become visible to our eyes 

 diiriiig the darkest eelii)se, or that leave their trace upon 



the photographic plates exposed during totality — nothing so 

 faint as the milky way could possibly be seen. 



On the opposite page, at the top left hand side, is a photo- 

 graphic reproduction from a paper copy of the corona kindly 

 sent me by Mr. Burnham, of the Lick Observatory. Below 

 is a photographic reproduction of a drawing by Miss Mabel 

 Loomis Todd, kindly sent me by Professor Todd, of Amherst 

 College Observatory, who is well known as an enthusiastic 

 student of eclipse phenomena. At the top right hand side 

 is a photograph from a sketch made from some glass posi- 

 tives of the same corona which have been sent to England. 



The eclipse took place at a time when there were btit few 

 sun-spots, and the corona observed has the marked character- 

 istics of a sun-spot minimum corona. The polar streamers 

 curve away uniformly from either pole, and the equatorial 

 extension is considerable. The equatorial gi-oups of structure 

 are bounded by rays which are greatly inclined to the 

 radial line drawn from the sun's centre to the region of the 

 limb from which they sjDring. 



In comparing the lower drawing with the upper pictures 

 of this corona, it should be remembered that Miss Todd's 

 drawing has not been turned so as to liring the sun's axis 

 vertical on the page with the north point uppermost. When 

 this is done the correspondence between the drawing and 

 the photographs can at once be traced. This drawing and 

 the paper photograph here reproduced do not show the rays 

 and brighter coronal structures visible on the glass photo- 

 graphs within the coronal area, but enough has already 

 come to England to show that a very fine series of photo- 

 graphs showing a great deal of structure has been obtained 

 during this eclipse. We look forward with much interest 

 to the series of comparatively large coronal photographs 

 taken with the large object-glass of Professor W. H. 

 Pickering, who was stationed at Willow, California. 



DRIFTING SAND. 



By Cecil Carus-Wilso.n, F.G.S. 



N walking along a sandy beach on a windy day 

 we may see vast quantities of dry sand blown 

 continually in one direction, in consequence 

 of sand being blown thus in the direction of 

 the iirevailing wind, accumulations called 

 dunes are formed, and these hillocks of drifted 

 sand form interesting objects of study on 

 various i)arts of our coast, as they are continually advancing, 

 dispersing, or changing their forms. 



On the north-western coast of Cornwall large sand drifts 

 occur, and have overwhelmed an old Constantine chapel, 

 the ruins of which may still be seen ; some of these sand- 

 hills reach a height of more than 300 feet. But our British 

 sand-hills are insignificant when compared with the Hurku 

 Hills in the Gobi Desert ; these gigantic sand-drifts extend 

 tbrty miles in length, and reach in some places an altitude 

 of 900 feet, having been formed by the action of the wind 

 upon the .sand of the desert. 



Sand dunes travel in the direction of the prevailing winds, 

 and if precautions are not taken they continue to advance 

 inland and overwhelm everything they encounter, even 

 streams ocoisionally failing to arrest their progress. In 

 Norfolk buildings have been buried, in Scotland vast tracts 

 of fertile land have been turned into barren wastes, and in 

 Ireland the ancient town ot Bannow has disappeai^d 

 beneath the advancing sand-drift. 



Some years ago, on the cjast of Crozon, near Brest, a 

 large hill of sand was removed by a gale, and the i-emains of 

 a village with a church and churchyard exposed to view ; 



