August 29, 1907] 



NA TURE 



451 



In the Entomologists' Monthly Magazine for August, the 

 attention of collectors is directed to the possibility that 

 the south European wingless earwig {Forficula dccipiens) 

 may be indigenous to England, since two earwigs with 

 aborted wings recently talien in the Isle of Wight appear 

 indistinguishable from that species. 



An elaborate cloth-bound illustrated catalogue (in 

 English) of the physical apparatus made by the firm of 

 E. Leybold's Nachfolgcr, of Cologne, has been sent to us. 

 It contains full descriptions of many pieces of apparatus, 

 with instructions for use, and should be seen by all science 

 teachers. 



OUR ASTRONOMICAL COLUMN. 

 Astronomical Occurrences in September : — 

 Sept. 3. Sh. Mercury and Venus in conjunction. Mercury 

 0° 26' N. 

 4. Daniel's comet in perihelion. 

 12. iih. 15m. Minimum of .\lgol (3 Persei). 



14. I3h. Venus in superior conjunction with Sun. 



15. Sh. 4m. Minimum of Algol (fl Persei). 



,, I4h. im. Transit (egress) of Jupiter's Sat. III. 

 (Ganymede). 



16. Iih. 13m. Mars in conjunction with Moon. 



(Mars 4° 27' S.). 



17. I4h. Saturn in opposiiion to the Sun. 



21. 7h. lom. to 7h. 59m. Moon occults 30 Piscium 



(mag. 47). 

 ,, 9h. 4in. to gh. 37m. Moon occults 33 Piscium 

 (mag. 46). 



22. I4h. 42m. to iSh. 20m. Transit of Jupiter's Sat. 



III. (Ganymede). 



23. i8h. Sun enters Libra. Autumn commences. 



24. I2h. 5lni. to I3h. 46m. Moon occults fj. Ceti (mag. 



4'4)- 

 „ iSh. im. Transit (ingress) of Jupiter's Sat. IV. 



(Calli.tn). 

 26. Ilh. 57m. to I2h. 59m. Moon occults 5- Tauri 



(mag. 47). 

 29. l8h. 58ni. Transit (ingress) of Jupiter's Sal. III. 

 (Ganymede). 

 Daniel's Cojuet (i907d). — The following is an e.Ktract 

 from the continuation of Dr. Stromgren's ephemeris for 

 comet iqo7ii as published in No. 4iq6 of the Astronomische 

 Nachrichlt'ti (p. 337, August 23) . — • 



Ephemeris 12/1. (M.T. Berlin). 



1907 a (true) 6 (iru.;) log r log A Br'ght 



h. m. , , nes-. 



Sept. I ... 8 50-8 ... +13 346 ... 97144... 0-0534 ... 19-1 



„ 3 ... 9 4-0 ... + I2 59-3 



,, 5 ... 9 i6'S ... + 12 22-6 ... 97123 ... 0-0847 ■■• '67 



,, 7 ... 9 29-4 ... + 11 44'6 



,, 9 ... 9 41-5 ... + 11 57 ■•■ 9 7250 ■•• o'l'39 ■•• i3'7 



An observation at Padua on August i8 gave corrections 

 of -t-3os. and — o'.y to this ephemeris. 



On September i the comet will be 8i'.5 N. of a Cancri, 

 whilst on September 8 it will be 66'.4 N. of o Leonis. 



The comet will rise about 2\ hours before the sun on 

 September i, and about two hours before the sun on 

 September 9. 



Further Observ.xtioxs of M.irs. — The August number 

 of the Bulletin de la Societc astronomique de France con- 

 tains an interesting paper by M. Jarry-Desloges giving 

 tile results of observations of Mars made during July last 

 at a temporary observatory erected on the summit of the 

 Revard at an altitude of 1550 metres. 



M. Jarry-Desloges and his collaborator, M. C. Fournier, 

 confirmed the doubling of the Solis Lacus announced by 

 Mr. Lowell. They also comment upon the cloudy appear- 

 ance of the Martian landscape in the northern hemisphere 

 as compared with the clear-cut features of the southern 

 hemisphere of the planet. 



The faint canals were difficult to observe, but the 

 Ganges was seen to be very broad and appeared double, 

 the two points where it emerges from the Aurorie Sinus 

 being seen quite sharply ; the observer states, however, 

 that this observation needs confirming. 



NO. 1974, VOL. 76] 



On Julv i() the region north of Lacus Niliacus was 

 clear, but twenty hours later, on July 20, details of white 

 spots could be seen ; thus it appears that in less than 

 twentv hours the clouds or mists which covered this part 

 of the planet vanished. 



\ Suspected, L.^rge Proper Motion. — Having occasion 

 to measure the places of three B.D. stars (B.D. -I- 1°-2720, 

 + i''.2722, and -i-o^^oST) on his star photographs. Prof. 

 Barnard found that the positions determined by him for 

 two of the stars differed considerably from the B.D. posi- 

 tions. That of i''-2720 is unusually discordant with the 

 B.D., though the difference may be due to an error in the 

 latter ; but in the case of o°.2957 the difference between 

 Prof. Barnard's position and that determined at Bonn 

 amounts to nearly a second of time. Therefore, if the 

 observations are correct, the star B.D.-l-o°-2957 must have 

 a considerable proper motion (Astronomische Xachrichten, 

 Xo. 4105, p. 313, .August 7). 



The .Astrographic Chart. — From No. 386 of the 

 Uhservalory (p. 329, August) we learn that the Potsdam 

 Observatory does not intend to take and distribute the 

 long-exposure photographs (chart plates) of the zone 

 (+32° to -1-39°) allotted to it. The work will be done 

 at the Royal Observatory of Belgium, which is being re- 

 organised on a somewhat liberal scale. 



The Simultaneous Invisibility of Jupiter's Satellites. 

 — On March 7 we referred in these columns to the simul- 

 taneous invisibility of Jupiter's four major satellites on 

 October 3 ne.xt. In the .August number of the Bulletin 

 de la Societc astronomique de France (p. 356) M. 

 Klammarion gives fuller details of the phenomenon, and 

 shows, by means of a diagram, the disposition of the four 

 satellites, in regard to Jupiter, between the hours of 

 iqh. 56m. and 2oh. 6m. on the date named. As Jupiter 

 docs not rise until after midnight, European observers 

 will not be able to watch this unusual spectacle ; it will, 

 however, be visible in .Asia and Oceania. 



The first observation of this phenomenon was made by 

 Galileo on March 15, 161 1, and only on eight occasions 

 since then has it been observed. 



Latitude-variation and Longitude Determin.\tions. — 

 Part i., vol. ix., of the Annalen dcr Stcrnuidrte in Leiden 

 contains accounts of a series of latitude-variation observ- 

 ations made bv Father J. W. J. A. Stein duririg the 

 period June, iSqq, to July, iqoo, and of a determination 

 of the difference of longitude between Leyden and Ubags- 

 berg made by the director of Leyden Observatory, Dr. 

 H. G. van de'Sande Bakhuyzen, and M. J. H. Wilterdink. 



Father Stein emploved the Horrebow method, making 

 1590 observations on 117 nights. He discusses the observ- 

 ations, the instrument, and the reductions at some length. 



Ubagsberg is a geodetic station situated in the province 

 of Limbourg, between Maastricht and .Aix-la-Chapelle, and 

 is an important point from the fact of its having been 

 made a station in three distinct triangulations. The 

 difference of longitude between the geodetic pillar at 

 Ubagsberg and the meridian circle at Leyden was found 

 to be -t-sm. 52-3i4s. +0-0158. 



The Colours and Spectra of Stars.— .A paper by Mr. 

 W. S. Franks, appearing in No. 8, vol. Ixvii., of the 

 Monthly Notices (R.A.S.), discusses the relation between 

 the colours and spectra of star classes. 



He tabulates 1360 stars under colour, as observed by 

 members of the B.A.A., and spectra as given in the 

 Harvard publications, and finds, in general, a very close 

 connection between the two features. Of 282 helium 

 stars, 125 belong to the white or O colour class, whilst 

 168 of the 377 hvdrogen stars come under the same head- 

 ing. On the other hand, 210 of the 241 solar stars come 

 under the colours between Y" and Y'. 



Whilst making the investigation Mr. Franks was 

 impressed bv the marked affinity of helium and bright- 

 line stars (types B and O) with the galaxy. All the bright- 

 line spectra met with were in or near the Milky Way. 

 and when one remembers that the Wolf-Rayet stars, all 

 the Novae, and the majoritv of short-period variables are 

 also galactical, it is obvious that the Milky Way is, in 

 some way yet undetermined, probably the seat of cosmical 

 actions of primary importance. 



