35o 



NA TURE 



[August 9, 1888 



man caught it by its tail, when it attempted to bite him. Prof. 

 Liitken states that hitherto only three specimens of this fish have 

 been caught, viz. one at Madeira, one in Greenland, and one 

 previously in Iceland. It is believed that this is the mysterious 

 fish the fax-dl, i.e. the eel with a mane, of which the Faroe 

 fishermen stand in such awe. 



The Assistant Superintendent of the Forest Department of 

 Penang has tried the raising of mahogany-trees from seeds, but 

 with what success is not yet known. He also tells us that a 

 trial venture in cultivating patchouli has proved very successful. 

 Experiments in growing olives, oranges, citrons, &c, have 

 proved encouraging, and trials with European vegetables show 

 that tomatoes, carrots, lettuce, onions, celery, &c, can be 

 successfully cultivated in the Straits Settlements. 



In "The Fodder Grasses of Northern India," just published 

 at Roorkee, Mr. J. F. Duthie gives an instructive account of the 

 more important kinds of grasses that are used in the plains of 

 Northern India either for fodder or for forage. Several of the 

 plains species extend up to considerable elevations on the 

 Himalaya, but Mr. Duthie has omitted all mention of those 

 which are exclusively Himalayan. The area of country to which 

 the work refers, and which coincides with that over which 

 his botanical researches generally will in future be conducted, 

 extends from the north-west frontier, and includes the Punjab, 

 the North- West Provinces, and Oudh, Sindh, Rajputana, Central 

 India, and the Central Provinces. 



A new edition of the Catalogue of Lewis's Medical and 

 Scientific Library has just been issued. It includes a classified 

 list of subjects, with the names of those authors who have dealt 

 with them. 



The first University of Siberia has just been opened at Tomsk. 

 It has for the present only one Faculty, that of Medicine. How 

 urgently necessary the establishment of this Siberian Faculty of 

 Medicine has become may be seen from some figures sent to the 

 Times the other day by its St. Petersburg Correspondent. The 

 practice of one doctor is supposed to extend over each of the 

 following districts, with their respective populations : — Tobolsk, 

 129,785 square versts, 110,323 inhabitants; Akmolinsk, 87,833 

 square versts, 80,062 inhabitants; Semipalatinsk, 85,705 square 

 versts, 100,225 inhabitants. In short, there are only twenty-two 

 doctors over an enormous territory of 2,815,547 square versts. 



In the article " Lord Armstrong on Technical Education," in 

 our last issue, an unfortunate slip occurs at p. 314, in the second 

 column, which destroys the force of the argument : ^74,000, not 

 ^24,000, should have been stated as the sum which it was pro- 

 posed to spend on the erection of a new chemical department 

 of the Zurich Polytechnicum. 



The additions to the Zoological Society's Gardens during the 

 past week include a Purple-faced Monkey {Semnopithecus leuco- 

 prymnus $ ) from Ceylon, presented by Mr. Martin J. Cole ; a 

 Rhesus Monkey {Macacus rhesus A ) from India, presented by 

 Mr. Reginald S. Knott ; three Black-eared .Marmosets (Hapale 

 penicillatd) from South-East Brazil, presented by by Mr. T. A. 

 Deintje ; a Chipping Squirrel ( Tamias striatus) from North 

 America, presented by Mrs. Matveiff; a Common Squirrel 

 (Sciurus vulgaris) British, presented by Mr. R. Grant Watson ; 

 a Tayra (Galictis barbara 6 ) from South America, presented by 

 Mrs. J. H. Pollard ; a Lesser Sulphur-crested Cockatoo {Cacatua 

 sulphured) from Moluccas, presented by Mr. J. Wolfe Barry ; a 

 White-backed Piping Crow {Gymnorhina leuconola) from. Aus- 

 tralia, presented by Miss Alice Rutherford ; a Herring Gull 

 {Larus argentatus), British, presented by Mrs. Huthwaite ; an 



Ashy-headed Gull {Larus cirrhocephalus), a Bittern 



(Bulorides ) from South America, presented by Dr. A. Boon, 



C.M.Z. S. ; a Common Kestrel (Tinmcnculus alaudarius), 

 British, presented by Mr. W. A. W. Jones ; a Smooth Snake 

 {Coronella Icevis) from Hampshire, presented by Mr. E. G. 

 Meade- Waldo ; a Rhesus Monkey {Macacus rhesus <J ) from 

 India, a Common Boa {Boa constrictor) from South America, an 

 ^Esculapian Snake {Coluber ccsculapii) from Langenschvvalbach, 

 Germany, deposited. 



OUR ASTRONOMICAL COLUMN. 



Encke's Comet. — Encke's comet was picked up at the Cape 

 Observatory on August 3, its place at 6h. 10m. 56'6s. being 

 recorded as R.A. I2h. 12m. 59s. ; Decl. 17 27' 46" S. This 

 compares with Dr. Backlund's ephemeris {4str. Nach., No. 

 2843) as follows : O - C ; R.A. + 4m. 43s. ; S. Decl. + 34' 52". 

 The ephemeris for the next few days runs as below : — 



For Berlin Midnight. 



Aug. 



The brightness at discovery is taken as unity. 



The Mass of Titan. — The values which have been deduced 

 for the mass of Titan by different astronomers showing a wide 

 diversity, Mr. G. W. Hill has undertaken, in Gould's Astro- 

 nomical Journal, No. 176, anew determination of this constant 

 from the influence of Titan on the motion of Hyperion. 

 Assuming Hyperion to be in opposition to Titan, at the same 

 time that it is in perisaturnium, then, at the end of the half- 

 synodic period — viz. 31 -8182806a 1 . — it would be in conjunction 

 with Titan ; and but for the action of Titan, <f>, the angle the radius- 

 vector makes with the direction of motion, would = 90°8'5i"'S5. 

 But the influence of Titan reduces this to a right angle, and this 

 effect may be used to discover the mass of that body. Com- 

 puting the motion of the line of apsides during the half-synodic 

 period from opposition to conjunction, all powers but the first 

 of the disturbing force being neglected, the value of Aw corre- 

 sponding to the argument 3i - 8i828d. was found to be -2634" 

 instead of - 5898", as given by observation. The mass, there- 

 fore, of Titan would require to be changed from 1/10,000, the 

 value assumed at first, to 1/4466. The eccentricity of the orbit 

 of Titan, 0028, had been neglected, and that of Hyperion 

 taken as o*i. With this better value for Titan's mass, the path 

 of Hyperion from opposition to conjunction is then traced by 

 mechanical quadratures, no powers of the disturbing forces being 

 neglected. The two unknowns to be determined were — the velo- 

 city with which Hyperion should start from opposition, and the 

 mass of Titan ; and the two determining conditions — that the 

 conjunction should take place 3l"8i828d. after opposition, and 

 that Hyperion must be then moving at right angles to its radius- 

 vector. The resulting mass is found to be 1/4714, and the 

 osculating elements of Hyperion at opposition — 



Daily n = 6o963" - 23942 

 log a - 0-0823532 

 e — 0-0994706 



Prof. Newcomb, in one of the "Papers for the Use of the 

 American Ephemeris," vol. hi., part 3, has also described the 

 perturbations of Hyperion arising from the action of Titan, and 

 deduced the mass of Titan as 1/12,500, but Mr. Hill points out 

 hat this value should have been divided by 3. M. Tisserand's 

 value from a similar inquiry, 1/10,750 {Comptes rendus, tome 

 ciii. No. 9), stands out in strong contrast with Prof. Hill's result.; 

 but Prof. Ormond Stone, on the other hand, who had obtained 

 a larger result, has more lately, after correction of an error in 

 his investigation, brought it down to a value closely according 

 with that of Prof. Hill. 



