March 26, 1896] 



NATURE 



495 



The opening address for the Session 1894-95, delivered to 

 the Royal Physical Society of Edinburgh by Prof. H. A. 

 Nicholson, has recently been published in the Proceedings of 

 that Society, and will be found to be an admirable summary of 

 the evidence that has accumulated of late years against the 

 doctrine of Ocean Permanence. The distribution of land and 

 sea in former periods is discussed, and the truly abyssal 

 characters of certain sediments now forming part of continental 

 masses are pointed out in some detail, while mention is made of 

 the evidence for a former Antarctic continent, and other matters 

 are more briefly discussed. 



A RECENT number of the Annali of the Meteorological and 

 Geodynamic Office of Rome contains an interesting paper, by 

 S. Arcidiacono, on the Syracuse earthquake of April 13, 1895. 

 The disturbed area comprises the south-east corner of Sicily. 

 On the map which accompanies the paper, eight isoseismal lines 

 are drawn, corresponding to intensities i to 8 of the Rossi-Forel 

 scale. These are elliptical in form, and have a common axis 

 running from Cape Passero in a north-westerly direction through 

 Vizzini, which is close to the centre of the meizoseismal curve. 

 Applying the method of Dutton and Hayden, the depth of the 

 seismic focus is estimated at about 7400 metres. The axis of 

 the isoseismals coincides nearly with that of the ridge of Monte 

 Lauro, and joins the two principal volcanic centres, now extinct, 

 of the Val di Noto. 



The additions to the Zoological Society's Gardens during the 

 past week include a Diana Monkey ( Cercopithecus diana, i ) 

 from north of River Prah, Ashanti, presented by Captain Edgar 

 E. Bernard; an American Tapir (Tapiriis afiiericanus, S) 

 from Brazil, presented by Mr. Basil J. Freeland ; a Mark- 

 hoor {Capra megaceros, <J ) from Peshawur, presented by Colonel 

 Paterson ; three Canarian Laurel V\gi:ons (Colninba /anrivora) 

 from the island of Gomera, Canary Islands, presented by Mr. 

 E. G. B. Meade-Waldo ; a Common Mynah {Acridothcres tristis) 

 from India, presented by Mrs. Sibyl E. Kennedy ; a Herring 

 Gull (Lams argentattis), British, presented by Dr. E. Goddard ; 

 two Grey \c\iV\Q\xmons(IIerpestes griseus) from India, deposited ; 

 t wo Amherst Pheasants ( Thaumalea ainherstne, 9 9 ) from 

 Szechusan, China ; two Swinhoe's Pheasants {Euplocatiius 

 swinhoii, <J 9 ) from Formosa, a Bar-tailed Pheasant {Phasianus 

 reevesi) from North China, two Great American Egrets [Ardea 

 e,^etta) from America, a Porto Rico Pigeon ( Coltimba eorensis) 

 from the West Indies, a Vinaceous Pigeon (Colwnba vinacea) 

 from South America, two Rosy Parrakeets {Palczornis rosa, <J 9 ) 

 from Burmah, two Musky Lorikeets [Trichoglosstis concinmis, 

 S 9 ) from Australia, purchased ; two Barbary Wild Sheep 

 {Ovt's tragelaphus, <J 9 ), born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



The Fifth Satellite of Jupiter. — The opposition of 

 J upiter in 1 894 occurred at a very unfavourable time for observa- 

 tions at Mount Hamilton, but a few measures of the fifth 

 satellite were secured with some difficulty by Prof. Barnard. 

 During the ol)servations of the satellite, the planet was obscured 

 by a piece of smoked mica covering half the field. For the 

 measurement of distances the micrometer wires were usually 

 placed perpendicular to the belts on the planet ; but on Novem- 

 ber 18 they were set parallel to the belts, and these measure- 

 ments accordingly enable the Jovian latitude of the satellite to 

 be determined. Only one eastern elongation was observed. 

 This was on December 3, and the distance was found to be 

 59"'5 ; oi^j reduced to the mean distance of the planet = 5*20 

 astronomical units, 48"*i7. On this date the elongation occurred 

 at 23h. 43 ■6m. G.M.T., the corresponding time in Marth's 

 ephemeris being 23h. 42m. G.M.T., so that the observed time 

 was over a minute behind the computed time. The ephemeris 

 is based on a period of iih. 57m. 22 •6s., and the observed 

 elongation indicates that this period will represent the motion of 



NO. 1378, VOL. 53] 



the satellite with sufficient accuracy to find it for several years 

 to come (Astronomical Journal, No. 367). 



The Yerkes Observatory. — Additional particulars as to 

 the proposed equipment of the new Verkes Observatory of the 

 University of Chicago are furnished by Bulletin No. i, the first 

 of a series of notices which will be published at irregular in- 

 tervals in the Astrophysical Journal. The resident staff is to 

 consist of Messrs. Hale, Burnham, Barnard, Wadsworth, Eller- 

 man, and Ritchey, the last-named as optician. The 40-inch 

 object-glass has been completed by Mr. Alvan Clark, and recent 

 tests have shown the definition to be fully equal to that of the 

 Lick telescope, while the light-gathering jxiwer is considerably 

 greater. Electro-motors are provided to give the various move- 

 ments to the instrument and to the elevating floor. The attach- 

 ments to the great telescope include a solar spectroscope, a 

 spectroheliograph for photographing the solar chromosphere in 

 monocliromatic light, a stellar spectroscope, and a photohelio- 

 graph of long focus for photographing the direct image of the 

 sun on a large scale. A 12-inch refractor and a 24-inch reflector 

 will also be erected. The meridian-room is designed to contain 

 a large meridian circle, but will be provisionally occupied by a 

 transit instrument. An instrument shop and optical laboratory 

 will be fully equipped with the necessary tools, and it is hoped 

 that it will be possible to construct many of the instruments and 

 laboratory apparatus which may be required in occasional in- 

 vestigations. The main building is now under roof, and will 

 be completed during the summer. 



The Proper Motion of t Tauri. — A discussion of the 

 meridian observations of t Tauri, which has been undertaken 

 by Dr. Fritz Cohen (Ast. Nach., 3341), indicates a variable 

 amount of proper motion in declination, but there is less 

 certainty as to the motion in right ascension. For an 

 explanation of the irregularities it is suggested that the star 

 is attended by a dark companion similar to that associated 

 with Procyon, and only giving evidence of its existence by its 

 gravitational effects on the brighter star, causing it to describe an 

 orbit round the common centre of gravity. It is true that the 

 star is already known to be double, the magnitudes of the com- 

 ponents being 4 '5 and 8*5 ; but the distance of the visible 

 companion is so great (79"). that the detection of an orbital 

 movement in the comparatively short period covered by the 

 meridian observations is scarcely probable. There is an increase 

 of 11" in the distance measured in 1823 as compared with that 

 determined in 1783, but as the distance and position angle in 

 1823 agree substantially with those in 1895, the earliest recorded 

 measure is not to be depended upon. An investigation of the 

 movements of the star by means of micrometric measurements in 

 relation to neighbouring stars is suggested. The association of 

 dark bodies with bright stars, in some cases producing variability 

 either by eclipses or other means, but in others having no 

 appreciable effect on the brightness, is a very notable feature of 

 recent astronomical discoveries. 



Two Remarkable Solar Prominences.— Father Fenyi 

 reports the observation of two very striking solar prominences 

 (Astrophysical Journal, vol. iii. p. 192). One observed on July 15 

 last was remarkable for its enormous velocity of 858 km. per 

 second in the line of sight ; the other, on September 30, for its 

 great height of 11' 28", which it attained with a mean velocity 

 of 448 km. per second. 



The first one was found precisely at a point on the sun's limb 

 where a group of sun-spots was passing out of view, and its 

 form changed with extraordinary rapidity. 



The second prominence was unusually bright, and at 10 a.m. 

 was about i' high ; eleven minutes later it had mounted to 4', 

 and the maximum altitude of 11' 28" was reached at 10.20, the 

 velocity in the line of sight then being 746 km. per second. 

 Half an hour from the beginning, the prominence was only 3' 16" 

 above the photosphere. The spot associated with the latter 

 prominence showed a considerable proper motion in the earlier 

 days of its existence, amounting to about 600 km. per hour 

 The convergence of some of the brighter "stream lines" of the 

 prominences towards a spot was especially marked in these ob- 

 servations, and it is suggested that they have a radial arrangement 

 with respect to the spots. This structure seems to point to the 

 existence of currents in the solar atmosphere, directed either 

 towards the interior of a spot, or outwards from it. 



It is stated that an explosion taking place over a sun-spot 

 would accord well with the appearances usually seen in the great 

 prominences which have been observed at Kalocsa, but it is by 

 no means asserted that actual explosions take place. 



