2s6 



NA TURE 



[January 12, 1905 



Messrs. J. J. Griffin and Sons have sent us specimens 

 of " Vitro-Ink," which is a non-corrosive ink for writing 

 on glass, celluloid, wood, or other material. The ink may 

 be used with an ordinan.' pen, and flows quite readily. A 

 ■ useful property is that it may be completely removed by 

 means of a damp cloth at any time before it has set hard, 

 so that mistakes can be rectified without difficulty. The 

 ink will be found of especial service in labelling such things 

 as laboratorj' or photographic dark room bottles, where 

 labels of ordinary type quickly become discoloured or worn 

 away. When written on with vitro-ink the inscriptions 

 entirely resist strong acids, and it is only prolonged action 

 of strong alkalis or boiling water which may efface the 

 material. Microscopic slides, lantern slides, and glass or 

 celluloid photographic negatives may be labelled and 

 numbered direct, and as the ink is quite unaffected by 

 alcohol it can also be employed for biological or other 

 specimens which it may be necessary to preserve in spirit. 

 Another useful field for this ink will be in the rapid pro- 

 duction of diagrammatic lantern slides for class or lecture 

 illustration, as the design may be drawn direct on the glass 

 during actual projection, thereby placing considerable 

 facilities in the hands of lecturers or others desiring to 

 employ the screen in place of a blackboard or prepared wall 

 diagrams. The ink can be especially recommended to 

 photographers as an efficient labelling agent, showing good 

 contrast in the dark room light, and capable of being 

 washed clean instantly whenever the names become stained 

 from the unavoidable o.xidation of the various solutions 

 employed. 



Mr. a. Henry Savage Landor's new book, " Tibet and 

 Nepal," will be published within the next few days by 

 Messrs. A. and C. Black. 



Messrs. George Bell and Sons have published a 

 teacher's edition of part i. of " Elementary Algebra," bv 

 Messrs. W. M. Baker and A. A. Bourne. The arrangement 

 by which the answers are printed on the page opposite to 

 the examples which are to be given to pupils to work out 

 should prove convenient for the teacher during class work. 



OUR ASTRONOMICAL COLUMN. 



Discovery of a Sixth Satellite to Jupiter. — A telegram 

 received from the Kiel Centralstelle announces the discovery 

 of a sixth satellite to Jupiter by Prof. Perrine. The exist- 

 ence of the object was suspected in December, 1904, and 

 was confirmed by an observation made on January 4. The 

 position angle on that date was 269°, and its distance from 

 the planet 45', the latter quantity decreasing 45" daily, 

 whilst the apparent motion was retrograde. 



A later communication from Kiel states that the dis- 

 covery was made with the Crossley reflector, observations 

 of the satellite having been made on December 3, 8, 9, and 

 10, 1904, and January 2, 3, and 4. 



Comet 1904 d (Giacobini). — ."Vnother set of elements and 

 an ephemeris for comet 1904 d have been calculated by 

 Herr M. Ebell from positions determined on December 17, 

 21, and 26, 1904, and are given below. 

 Elements. 

 T = 1904 November 4-22 (Berlin). 



CO = 41 I5'6"| 

 a =218 320 11904-0 

 ! = 99 39-1 J 

 log ,j =0-27536 



Ephemeris (izh. Berlin). 



Elements and Ephemeris for Comet 1904 e. — The follow- 

 ing elements and ephemeris for Borrelly's comet (1904 e) 

 have been calculated by Dr. Elis Stromgren from the posi- 

 tions determined on December 31, 1904, January i and 2 : — 

 Elements. 

 T =1905 January I 2710 (Berlin). 



00 =341 23-22"! 

 8 = 69 54-82 ]- 1905-0 

 i = 35 3070 J 

 Iog7=oi9344 



Ephemeris i2h. (Berlin). 



Btight- 



h. m. s. , , ness 



Jan. 12 ... I 33 39 ... +1 17-4 ... 0-0870 ... 0-83 



,, 16 ... I 40 8 ... -i-4 18-7 ... 00985 ... 078 



,, 20 .. I 46 56 ... +7 13-6 ... 0-II07 ... 073 



Brightness at time of discovery =10. 



According to the above the comet will pass through the 

 south-eastern corner of the constellation Pisces into Aries, 

 and will be about twenty-five minutes west of a Piscium 

 on January 12 (Kiel Circular, No. 72). 



Colours of Stars in the Southern Hemisphere.^ 

 During the period October, 1903-March, 1904, Dr. J. 

 .Moller, whilst cruising in the tropical regions of the .Atlantic 

 and Pacific Oceans, made a number of observations of the 

 colours of 169 stars situated betw-een declination —20° and 

 the South Pole, all of which were about magnitude 35. 



The results of these observations are published in No. 

 3980 of the Astronomisclic Nachrichten, where the observer 

 aiso shows the reduction of his colour values to Osthoff's 

 scale and the differences between his own results and those 

 obtained by the latter observer. 



" The Heavens .\t a Glance." — The handy card calendar, 

 "The Heavens at a Glance," published by Mr. Arthur 

 Mee, Llanishen, price sevenpence, post free, is full of useful 

 information for amateur astronomers, .\mong other things 

 it contains a " celestial diary " which gives all the more 

 important astronomical events during each month, a table 

 showing the elements of the sun and planets, and a mass of 

 information relative to the brighter stars, variable and 

 double stars, and star clusters and nebulse. 



Intended to hang on the observatory wall, the calendar 

 forms a most useful adjunct to the more voluminous 

 almanacs which it epitomises. 



Astrono.mical " Annuario " OF the Turin Observatory. 

 — The first annual publication of the Turin Observatory 

 appeared in the year 1787, but for various reasons their 

 appearance has not been continuous. A new series com- 

 mences with the " .■\nnuario " for the present year, and in 

 the preface Signor Boccardi, the director, explains its raison 

 d'etre by the statement that it does not contain the 

 ephemerides, star-places, \-c., published in the larger 

 national almanacs, but deals more especially with the calcu- 

 lations and researches made at the Turin Observatory, and 

 fills up the gaps left by those almanacs. 



.'\s examples of this we may mention the tables which 

 contain the mean positions and the apparent positions at 

 upper culmination (Greenwich meridian) of 202 stars not 

 included in the "Nautical .\lmanac," the " .\merican 

 Ephemeris," or the " Connaissance des Temps." The 

 heliocentric coordinates of Jupiter and Saturn (for 1905 and 

 1906), the elements and ephemerides of various minor 

 planets, a mass of meteorological data, and a review of 

 the meteorology of 1903 are also given. 



Origin of Lunar Formations. — In a paper on " A 

 Possible Explanation of the Formation of the Moon," read 

 before the Royal Society of Edinburgh on November. 21, 

 1904 (see Nature, December 8, 1904, p. 143), Mr. G. 

 Romanes show-ed that there had never been sufficient heat 

 developed in the interior of the moon by gravitational com- 

 pression to account for volcanic action on its surface ; and 

 he explained how lunar markings could be accounted for on 

 his hypothesis by the impact of meteoritic masses. Dr. 

 Johnston-Lavis writes to say he has long held this view, 

 and reminds us that Dr. G. K. Gilbert developed the impact 

 theory of the formation of lunar craters several years ago 

 (see Bull. Phil. See. of Washington, vol. xii., pp. 241-292, 

 and Nature, vol. xlviii., p. 82, May 23, 1893). 



