Jan. 22, 1880] 



NATURE 



287 



and I shall be happy to have such for insertion in a paper now 

 neariy ready on the Huyghenian region of this nebula." 



For the convenience of such observers as may not have ready 

 access to the " Annals of the Astronomical Observatory of 

 Harvard College, vol. v.," which contains G. P. Bond's elabo- 

 rate memoir on the nebula of Orion, the following differential 

 positions of the stars mentioned by Prof. Holden, with reference 

 to l Orionis, are extracted : — 



Diff. R.A. Diff. Decl. Diff. R.A. Diff. Decl. 



It will be remarked that Prof. Holden states there are actually 

 no stars within the trapezium. Mr. Burnham's experience with 

 the i8i-inch refractor at Chicago is to the same effect. ; in the 

 notes to his last catalogue of double stars, he writes : "Several 

 observers have seen, or believe they have seen, other minute 

 stars in the trapezium, most of them using comparatively small 

 apertures. While making the measures given above, and at other 

 times, under very favourable conditions, the interior of the tra- 

 pezium and the vicinity of the principal stars were carefully 

 examined. There was not the slightest suspicion of any addi- 

 tional stars. If the sixth star itself had been double, with a 

 distance of l""0, it could not have been overlooked. I have 

 very little faith in the real existence of these suspected stars after 

 the failure of this and other large refractors to show them." And 

 he considers it is wholly improbable that they shonld all be vari- 

 able in such manner as to render them at all times invisible during 

 the last few years. Telescopes were not si perfect forty years 

 .since as they are now, and we might be perhaps justified in attri- 

 buting to optical illusion the supposed existence of the three stars 

 within the trapezium, recorded by De Vico in 1839, and the star, 

 near the " fifth," detected by Strove, which Gruithui-en claimed 

 to have discovered about the same time, and which he says 

 Schwabe had also seen with a 6-feet Fraunhofer. But what are 

 we to say to the observations of Dr. Huggins, as detailed in 

 vol. xxvi. of the Monthly Notices of the Royal Astronomical 

 Society ? They appear to point to something more than optical 

 illusion, and notwithstanding the negative testimony as to the 

 actual existence of stars within the trapezium, to render it desir- 

 able that a protracted examination of this region should be insti- 

 tuted with telescopes of suitable capacity. One of Dr. Huggins's 

 stars is not far from the position of a star in De Vico's diagram 

 "(see Memoria intorno a parecchie Osserz'azioni . . . in Collegia 

 Romano, V Anno 1839, plate I., and Grmthmsen'i A stronomisches 

 Jahrbuch, 1841, p. 143. 



The Total Solar Eclipse of January 1 1. — A Reuter's 

 telegram brings intelligence of the successful observation of the 

 total phase in this eclipse on the Santa Lucia mountain, Cali- 

 fornia, with the important addition that an intra-Mercurial planet 

 has been again seen. In the longitude of this mountain the 

 duration of totality upon the central line, employing the elements 

 of the Nautical Almanac, would be only 38 seconds, with the 

 sun at an altitude of 12°; if the semi-diameters adopted for 

 eclipses in the American ephemeris are used, the duration would 

 be even less — hardly 27 seconds. Under such circumstances it 

 must have required very minute and skilful preparation and 

 considerable smartness of execution to insure the results 

 announced. 



GEOLOGICAL NOTES 



The MSS. of Sartorius von Waltershausen, descriptive of 

 Etna, have been placed, we understand, in the hands of Prof, 

 von Lasaulx, of Breslau, with a view to publication. They will 

 complete the colossal pile which the veteran geologist erected 

 to the glory of his favourite mountain. 



Another distinguished and venerable vulcanolo.nst, 'Dr. 

 Abich has gone to Vienna to prepare his petrographical descrip- 

 tions of the Caucasian region, in which he has been so long at 

 work. The facilities for the most delicate analyses of rocks and 



minerals at Vienna have likewise attracted thither M. Renard, of 

 Brussels, who has been entrusted with the chemical and micro- 

 scopic investigation of the abyssal deposits brought by the 

 Challenger from its great ocean survey. M. Renard is at present 

 in this country arranging with the Challenger Commission as to 

 the prosecution and publication of his labours. His beautifully 

 drawn plates which illustrate the more remarkable facts brought 

 to light by the Challenger dredgings, are being exquisitely re- 

 produced by chromolithography in Vienna. 



In a recent number of the Bulletin of the United States 

 Geological and Geographical Survey of the Territories (a 

 publication still continued for a while, though the Survey itself 

 has ceased to exist), Dr. F. V. Hayden describes the Two Ocean 

 Pass which has for some years been known to separate the head 

 waters of the Yellowstone from those of the Snake River. He 

 confirms and extends previous accounts of this interesting locality, 

 showing that it is a flat meadow-like depression cut by erosion 

 on the watershed. During wet weather this marshy ground 

 becomes a lake which drains both ways, one branch finding its 

 way into the Pacific, and the other into the Atlantic, by one of 

 the longest routes for running water on the surface of the planet. 



Prof. Marsh continues his descriptions of the fossil treasures 

 continually arriving to increase the already ample stores at Yale 

 College. He remarks that while the Mosasauroid reptiles are 

 so rare in Europe that the type-specimen described by Cuvier still 

 remains the most perfect yet discovered here, and the only one 

 from which important characters have been made out, in North 

 America the group attained a marvellous development, and was 

 represented by several families with numerous genera and spe- 

 cies, of which the relics of not less than 1,400 distinct individuals 

 are contained in the museum at Vale. 



Dr. Michel Mourlon of Brussels has in preparation a 

 work on the geology of Belgium. It will form an octavo 

 volume of at least 500 pages, containing full descriptions of the 

 different geological formations, with unpublished plates of the 

 microscopic structure of rocks, copious lists of fossils, and an 

 account of the industrial resources of each formation, and will 

 be followed by a complete bibliography of the geology, palaeon- 

 tology, and lithology of Belgium. The re-issue of Dumont's 

 beautiful and most trustworthy geological map of Belgium natu- 

 rally suggests the desirability of some general guide to the public 

 in perusing the map or travelling through the country, for the 

 admirable prodrome of M. Dewalque can hardly now be procured. 

 Dr. Mourlon's position as one of the Conservateurs of the Royal 

 Museum of Natural History, and his experience as a field geolo- 

 gist both before and since his connection with the Geological 

 Survey of Belgium, give him exceptional advantages for the 

 preparation of such a work, which will no doubt be as duly 

 appreciated by his fellow-countrymen as it will be welcomed by 

 students of geology abroad. 



PHYSICAL NOTES 



Observations of phosphorescence phenomena in high vacua 

 of the nature described by Crookes and Maskelyne have been 

 lately made on a variety of substances by Herr Stiirtz of Bonn, 

 in company with Herr Miiller (IVied. Ann. No. 11). The fol- 

 lowing substances gave phosphorescence (those marked with an 

 asterisk were made red hot before being brought into the tube ; 

 in the ordinary state they showed 1 ittle or no phosphorescence) : — 

 Brucite,* magnesite,* phosphate of magnesia, pitch-blende, 

 wolframite, cerusite, adularia, orthoclase, * rkaolin,* axinite,* 

 silicate of zinc,* zinc-spar,* double spar, apatite, franklinite, 

 azure spar, fergusonite,* apophyllite,* dolomite, coelestine,* red 

 spinelle, cobalt-glance, stannite, baryta, chromate of iron, lazu- 

 lite, lepidolite, zinnwaldite, ankerite, greenockite, pectolith, 

 borax, cinnabar, leucite, sanidin, and Java meteoric stone of 

 1869/ A few luminous p ints were observed in crystals of 

 arsenical iron and antimonite. Pieces of a phosphorescent sub- 

 stance made red hot are luminous with a different colour from 

 that of pieces of the same not made red hot. In cerusite the 

 phosphorescence is lost through heating. The authors give a list 

 of substances which do not phosphoresce. 



A SYSTEM of electrical storing, considered to be free from the 

 disadvantages of other systems, is described by Professors 

 Houston and Thomson in the Franklin Institute Journal for 

 December, 1879. They use a saturated solution of zinc sulphate 

 in a suitable vessel, having at the bottom a plate of copper, to 



