February 2, 1899] 



NATURE 



;29 



the cephalic index from two measures of length and breadth of 

 the head. 



Mkssrs. Ginn am> Co. announce the forthcoming public- 

 ation of " A Laboratory iNIanual in Astronomy," by Mary E. 

 Byrd. The manual is designed as a handbook of laboratory 

 instruction to accompany the study of elementary and general 

 astronomy in secondary schools and colleges. The same firm 

 announces a college text-book of " Physics," by Profs. Charles 

 S. Hastings and Frederick E. Beach. 



The zoological material collected by Dr. Arthur Willey from 

 New Britain, New Guinea, Loyalty Islands, and elsewhere, 

 during his expedition in search of the eggs of the Pearly 

 Nautilus, is being studied by a number of distinguished zoo- 

 logists, and the lirst two parts of a work containing the results 

 have been published by the Cambridge University Press. It 

 is expected that five or six similar parts will be issued ; and 

 we defer our notice of the work until all of them have been 

 published. 



The density of liquid air is the subject of an interesting 

 paper by Prof. A. Ladenburg and Dr. C. Kriigel, in the 

 current number of the Beiiihh. The hydrostatic method with 

 a Westphal balance was employed. It is pointed out that a 

 determination of the density of liquid air obtained in the usual 

 way is of little value unless .iccompanied by a determination of 

 the exact composition of the mixture, since, as is well known, 

 after standing some time, the residual fluid is nearly pure 

 oxygen. In these experiments, the whole of the liquid was 

 allowed to evaporate into large gasholders, and the gaseous 

 mixture analysed. From these results, the authors calculated 

 that the density of normal liquid air containing 20'9 per cent, 

 of oxygen would be '871. It was found that the density of the 

 liquid containing 93'6 per cent, of oxygen was higher than that 

 of pure oxygen. It is suggested that this may be due to carbon 

 dioxide or krypton. 



Considering its exceptional behaviour with respect to 

 hydrogen, the metal palladium has not hitherto been used to 

 the extent that would have been expected as a reducing agent 

 in organic chemistry. The mode of application of palladium, 

 however, described by Dr. N. Zelinsky in the current number 

 of the Berichte, would appear to promise a more extensive 

 use of this metal. A zinc-palladium couple is prepared from 

 zinc and palladium chloride, in a manner similar to the well- 

 known zinc-copper couple. This is placed in alcohol, and 

 acid added until hydrogen gas just commences to be evolved. 

 .\t this stage the palladium black is saturated with hydrogen, 

 and produces energetic reduction of the alkyl iodide or 

 bromide, the acid and iodide being now added alternately. 

 Ilexamethylene, and the ethyl and methyl-hexamethylenes, 

 which are obtained with great difficulty from their halogen 

 derivatives by ordinary reducing agents, are produced in yields 

 of 70-75 per cent, of the theoretical, when the corresponding 

 iodides or bromides are treated in this way. 



The additions to the Zoological Society's Gardens during the 

 past week include a Chimpanzee {Anthropopithccus troglo- 

 dytes, 9 ) from West Africa, presented by Miss K. M. Burne ; 

 a Green Monkey (Cercopitlie<iis caililrichits, i) from West 

 Africa, presented by Mr. F. W. Coker ; a Two-spotted Para- 

 doxure (Nandiiiia binotata) from West Africa, presented by 

 Miss A. M. Decks ; a Black-headed Lemur (Lemur brtiniieiis, S ) 

 from Madagascar, deposited ; a Tui Parrakeet [Brotogerys ttti) 

 from Brazil, an Uva;an Parrakeet {Nymphicns uvaensis) from 

 the Island of Uvea, Loyalty Group, three Common Crowned 

 Pigeons {Goura coronatd) from New Guinea, purchased ; two 

 Barnard's I'arrakeets [Plalyccrais barnardi) from South 

 Australia, received in exchange. 



NO. 1527, VOL. 59] 



OUR ASTRONOMICAL COLUMN. 



Astronomical Occurrences in February : — 

 February 10. igh. Venus at greatest elongation 46" 46' 

 west. This planet rises nearly three hours 

 before the sun, and presents a brilliant appear- 

 ance in the south-east sky. 



10. Date of computed perihelion passage of Denning's 



comet (18S1 v.). 



11. loh. 39m. Minimum of Algol (fl Persei). 



12. 7h. 35m. to 8h. 28m. Occultation of the star 19 



Piscium (mag. 5 '2) by the moon. 

 14. Mars. Illuminated portion ofdisco'969. 

 14. Venus. ,, ,, „ 0517. 



14. 7h. 2Sm. Minimum of Algol (3 Persei). 



15. Jupiter. Polar diameter 35"'8. The planet rises 



at midnight, and is favourably visible after- 

 wards. 



16. I5h. 45m. to I7h. Transit of Jupiter's Sat. III. 

 iS. Sh. 53m. to loh. iim. Occultation of the star 



103 Tauri (mag. 5 '5) by the moon. 

 24. Saturn. Outer minor axis of the outer ring = 

 i6""S2. Polar diameter 15". The planet 

 may be well seen as a morning star. 



Harvard College Observatory. — In the fifty-third 

 annual report of this well-known observatory, Prof. Pickering, 

 the director, again chronicles the completion of an enormous 

 amount of work. With the east equatorial (i 5-inch), under 

 the charge of Mr. O. C. Wendell, about 25,000 photometric 

 light comparisons have been made, chiefly with the new polar- 

 ising photometer with achromatic prisms. This instrument was 

 also used in the photometric measurement of Jupiter's satellites 

 while undergoing eclipse. 



Similar photometric comparisons of variable stars, to the 

 number of about 1650, have been made with the west 

 equatorial (6-inch). These observations are now reduced and 

 will shortly be published. In addition, comparison stars have 

 been selected for sixty other variables, and the co-operation of 

 other astronomers in following up the stars when too faint for 

 the 15-inch is invited, for which purpose charts and lists of the 

 stars in question will be furnished on application. 



The reduction of the observations of fundamental stars with 

 the meridian circle, by the late Prof Rogers, were incomplete 

 at the time of his death, and are still therefore under discussion. 



With the meridian photometer the observations have been 

 made by the director. Extending over 152 nights, the number 

 of settings has been 73,684. This completes the work that was 

 planned in 1892 for this instrument, and it is proposed to send 

 it to Arequipa next spring, to revise the contents of the 

 Southern Harvard Photometry. 



Photometric observations of faint stars have also been com- 

 menced by the director using a 12-inch telescope mounted 

 horizontally, and having a Welsbach burner for artificial com- 

 parison. 



In connection with the spectroscopic work of the Henry 

 Draper Memorial, 2192 photographs have been taken with the 

 8-inch telescopes. By the examination of these and other plates 

 taken with the Bruce and Bache telescopes, Mrs. Fleming has 

 detected twelve new variable stars, six of which showed bright 

 hydrogen lines ; nine stars have spectra of the fourth type, seven- 

 teen of the fifth, and ten objects are catalogued as gaseous 

 nebulo;. In three known variables — \' Tauri, U Cancri, T 

 Capricorni — the hydrogen lines have been found bright. 



With the 1 1 -inch Draper telescope 873 plates have been 

 taken, and a photograph of aCanis Majoris obtained at mid-day 

 under conditions rendering it probable that bright stars could be 

 thus usehilly photographed when in transit. 



Photographs of stars near the pole have been taken with the 

 15-inch reflector, with the object of accurately determining the 

 constants of aberration, precession, and nutation. 



The examination of the photographs of star cluster.s for 

 variables has been continued, resulting in the detecting of 509 

 stars of this type. The most notable occur in the clusters 

 to Centauri, Messier 3, Messier 5, and Messier 15. 



With the Bruce photographic doublet, photographs have been 

 obtained which, with three and four hours' exposure, show no 

 distortion of the star images, and Prof. Turner reports favour- 

 ably on the freedom from distortion over an area of 4' x 4°. 

 Both chart plates and stellar spectra have been taken with this 

 instrument. 



