5^4 



NATURE 



[September 29, 1892 



or nine parts); "Fungus Flora," a classified text -book of 

 Mycology, by George Massee, author of " The Plant World," 

 with numerous illustrations, 3 vols., vols. i. and ii. ; "The 

 Framework of Chemistry," Part i, by W. M. Williams. 



University College, Liverpool, has issued its prospectus 

 of day classes in arts and science, and of the evening lectures, for 

 the session 1892-93. 



Part 48 of Cassell's New Popular Educator, with title-page 

 and contents to vol. viii., has been issued. The next monthly 

 part of the work will form the first part of a technical series of 

 Cassell's New Popular Educator, published under the title of 

 Cassell's Ne^v Technical Educator. 



Messrs. Dulau and Co. have published a catalogue of works 

 on electricity, galvanism, and magnetism — works which they 

 offer for sale. 



Four lectures on Cholera will be delivered by Dr. E. Symes 

 Thompson in Gresham College on October 4, 5, 6, and 7, at six 

 o'clock p.m. The lectures will be free to the public. 



The additions to the Zoological Society's Gardens during the 

 past week include a Rhesus Monkey {Macacus rhesus i ) from 

 India, presented by Mrs. TrafTord Rawson ; a Green Monkey 

 ( Cercopithecus callitrichus {, ) from West Africa, presented by 

 Mr. A. de Turckheim ; two Tigers [Felts tigris S ? ) from 

 India, presented by the Maha Rana of Oodeypore ; a Grey 

 Ichneumon {Herpestes griseus) from India, presented by Mr. Hugo 

 Marshall ; a Three-striped Paradoxure {Paradoxurus trivirgaius^ 

 from Java ; presented by Mr. Douce ; a Jackdaw {Corvus mone- 

 dula), British, presented by Lt.-Col. K. F. Darvall, F.Z.S. ; a 

 Common Fox {Cams vulpes), British, presented by Mr. Lucius 

 Fitzgerald ; an Indian Cobra {Naia tripudians), an Indian Rat 

 Snake {Ptyas mucosa) from India, presented by Mr. Arthur H. 

 Cullingford, F.Z.S ; a Common Boa {Boa constrictor) from St, 

 Lucia, W.I., presented by H. E. Sir Walter F. Hely Hutchin- 

 son, K.C.M.G ; a Common Chameleon {Chamceleon vulgaris) 

 from North Africa, presented by Miss Withers ; two Tarantula 

 Spiders {Mygale, sp. inc.) from Demerara, presented by Mr. H. 

 Strong; a Black-headed Lemur {Lemur hrunneus'^) from 

 Madagascar, a Duyker-Bok {Cephalophus mergens £) from 

 South Africa, two Demoiselle Cranes {Grtis virgo) from North 

 Africa, four Emus {Dromceus novcB-hollandicE) from Australia, 

 deposited; an Indian Chevrotain {Tragulus meminna) from 

 India, two Violet Tanagers {Euphonia violacea) from Brazil, a 

 Shag {Phalacrocorax gracilis) British, purchased ; three Wild 

 Swine {Sus scrofa) born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



The Variation of Latitude at V^3'LVio\K. —Astro- 

 nomische Nachrichten, No. 3 11 2, contains two communications 

 on the variation of the latitude at Pulkova, the first by Mr. B. 

 Wanach, who discusses some old observations, and the second 

 by Mr. S. Kostinsky, who has continued the former's recent 

 observations made before July, 1891. During the years 1890 

 and 1891, Mr. Wanach obtained some very definite results with 

 regard to this question by using the large Pulkova transit instru- 

 ment in the Prime Vertical, and the object of the present dis- 

 cussion is to find out if any like result can be discovered. The 

 observations used are those of W. Struve made between the 

 years 1840-55, O. Struve 1858-9, Com 1861-63, and Nyren 

 1879-82. If we employ those made in the years 1840-42 it is at 

 once noticed that to satisfy the conditions a variation in the 

 height of the pole of ±o"-i has to be assumed, while the maxima 

 and minima occur at different months of the year, the latter on 

 September, 1840, May, 1841, March, 1842, and the former on 

 January, 1841, September, 1841, and October, 1842. The 

 observations from 1843-63 present no direct fluctuations in the 

 value of the mean pole height, but show that it remains constant 

 NO. II 96, VOL. 46] 



or is proportional to the time during the whole period. Taking 

 the values of the mean pole height for the years 1879-82, as 

 obtained from a similar curve, it is found that a single sinus 

 curve is not sufficient for the comparison ; secondly, that the 

 mean pole height is not the same as it was in 1841 and 1891, but 

 is about c"-i5 greater; thirdly, that the chief maximum on 

 March, 1881 coincides with the chief minimum on September, 

 1880, that is, exactly coincides with the phases of the pole 

 height. It also happens that the series, which take 

 more than two years, give only one distinct maximum 

 and minimum (instead of two, as would be expected). 

 Coming now to Mr. S. Kostinsky's work, whose observations 

 were made by W. Struve's method with the aid of a large transit 

 instrument by Repsold, the variation of latitude is clearly shown. 

 With the aid of the curve, which accompanies the paper,, 

 the maximum of the latitude occurs on October 4, 1891. Owing 

 to the observations not being quite complete, the epoch of mini- 

 mum is uncertain, but the curve shows that it will take place 

 somewhere before the end of the month of May 1892. Com- 

 paring this curve with that obtained by Mr. Wanach in the year 

 1891, we have for the dates of the greatest and least values of 

 the latitude — 



Max. in 1890, September 14. (^ = 59 46 18-39 



Min. ,, 1891, April 15 I7"79 



Max. ,, 1891, October 4 1844 

 Min. „ 1892, May 20-31 (about). 



Double Star Observations.— The second part of 

 Appendix I. to the Washington Observations for 1888 contains 

 the observations of double stars made at the United States 

 Naval Observatory during the period 1880-1891, by Prof. 

 Asaph Hall. These observations have been made with the inten- 

 tion of carrying on the work that was begun with the same 

 instrument in 1875. The stars here observed are mostly known 

 binaries. Some are of special interest on account of their short 

 periods, while again the motion of others will be found to be 

 very slow. This volume will be welcomed by all double star 

 observers, for in such a work as this a strict comparison of 

 observations is needful in such measurements as are here dealt 

 with. The form in which the observations are printed is the 

 same as was the case in 1881. The star's name is first 

 given, followed by its right ascension and declination, 

 and its magnitude. In the first column the date of 

 observation in years and decimals of a year is given, while in 

 parallel columns the sidereal time of observation to the first 

 decimal of an hour, position angle, distance, and weight of 

 observation are similarly inserted ; in two other column^ the 

 magnifying power employed and occasional notes are added for 

 reference. The volume concludes with an index of all the stars 

 observed. The numbers of the stars are for the most part 

 those of the Struves ; but Prof Hall, in recording those lamt 

 stars in the Pleiades, has referred them to Bessel's list of fifiy- 

 three stars in this group. Bessel's stars themselves he has 

 numbered in the order they appeared in the Astrono- 

 mische Untersuchimgen, first volume, p. 237. 



Solar Observations at Rome.— In the August number 

 of the Memorie delta Sociefa degli Spettroscopisti Italiani, Prof. 

 Tacchini contributes, in tabulated form, the results of the solar 

 observations made at the Royal Observatory during the second 

 three months of this year. Considering first the faculse, they 

 seemed most numerous on the southern hemisphere, there being 

 an excess of 13. Latitudes 20° to 10° north, and 20° to 30" 

 south, were the zones of greatest frequency, the number recorded 

 being 49 and 50 respectively. Taking the whole numbers for 

 both hemispheres the table shows a distinct increase, the numbers 

 for the three months being 71, 75, and 97. With reference to 

 the spots, the two hemispheres seem to have been evenly dis- 

 tributed, the numbers seen amounting to 48 and 46 respectively. 

 The zones of greatest frequency were found to be ± 10 ± 20 , 

 the number of spots recorded being 29 and 22 ; but in zone 

 - 20°- 30° as many as 19 were noted, the number in the corre- 

 sponding zone of the northern hemisphere amounting only to 

 eight. The record of eruptions for this period is not very high, 

 six only being seen in the northern and three in the southern 

 hemisphere ; the zone of maximum frequency for the northern 

 hemisphere is -f 10' -f 20°, the same as that for spots, the six 

 observations occurring in this zone alone ; for the southern 

 hemisphere the three eruptions were observed in each of the 

 10° zones included between — 10° and ~40°, 



