December 27, 1894J 



NA rURE 



207 



ture of the cooled liquid its phosphorescence diminished, 

 until at -65° it entirely disappeared. The portion of the 

 tube above the alcohol continued to phosphoresce strongly. 

 After thirty minutes' immersion in the cooled alcohol, the 

 tube was removed, and as it gradually acquired the tempera- 

 ture of the air, the lower portion began to glow. Before the 

 glow — blue, green, or orange in colour, depending on the nature 

 of the metallic sulphide — entirely disappeared, the colour be- 

 came a faint yellow. It was found by comparative e.xperiments 

 that the alcohol exerted no specific influence on the results. 

 These seemed to be entirely dependent upon the diminution or 

 total cessation of molecular vibrations at the low temperature. 



An interesting paper on the Sicilian earthquakes of last 

 August has recently been published by Dr. Mario liaratta (Boll, 

 della Soc. Geogr. Hal., Ott., 1894). The first shock of the series 

 was felt on July 29 at Randazzo, and was succeeded by several 

 other slight shocks, mostly in the Lipari Islands. Then came 

 the severe earthquake of August 7 at i2h. 5Sm. p.m., and the 

 still stronger one of August 8 at 5h. l6m. a.m. (Greenwich 

 mean time). These affeCeJ chiefly the south-eastern slope of 

 Etna, and were followed by more than twenty shocks in the 

 same district, lasting until August 26. The meizoseismal area of 

 the principal earthquake (August 8) is only about 7 km. long 

 and 3 to 4 km. broad, and, as the intensity diminished rapidly 

 outwards, it would seem that the focus cannot have been far 

 from the surface. Moreover, the longer axis of thi> area runs 

 north-west and south-east, and, when produced, passes through 

 the central crater of Etna It therefore probably coincides with 

 a radial fissure of the cone, and indeed is not far, if at all, dis- 

 tant from that along which the eruption of 1329 took place. 

 The pressure exerted by the column of lava in the central 

 funnel, or by the forces which have raised it to its present 

 height, may have caused such a fracture to be reopened. Thus, 

 it is not impossible that the recent earthquakes indicate an un- 

 successful attempt at a new lateral eruption. 



Ft7RTHER details relating to the same earthquake; are given 

 in the Bollcttino MdeorUo (Suppl. 1 10) of the Geodynamic 

 OfiSce of Rome. The depth of the focus of the principal earth- 

 quake, according to Prof. Ricco, was about 4 km. The pulsa- 

 tions were recorded at Rome bythe great seismograph, consisting 

 of a pendulum 16 metr-is long, with a mass of 2co kg. ; the 

 first traces at Sh. 17m. 30;., and the principal maximum at 

 Sh. l8m. 55s. The puteometer of the Observatory of Catania 

 shows a .trace about 21. l mm. long, indicating a temporary 

 lowering of the well-water, which, in returning, stopped about 

 4 mm. below its original level. 



The additions to the Zoological Society's Gardens during the 

 past week include a Yellow Baboon {Cynoccphalus babottin, 9 ) 

 from Fort Salisbury, South Africa, presented by General 0*en 

 Williams ; two Grisons {Galiclis vitlala) from Brazil, presented 

 by Mr. H. A. Caflett ; a Song Thrush ( 7"H;-i/«j miisictis), a 

 Goldfinch ( Car(r'j«//.t elcgans), British, presented by Mr. B. M. 

 Smith; a Grenadier Weaver Bird {Eiiptcctts ory.x, i) from 

 West Africa, presented by Lady McKenna ; a Wild Cat 

 (Felis calm) from Scotland, deposited ; five Shore Larks 

 (Otocorys alpestris), British, purchased. 



OUR ASTRONOMICAL COLUMN. 



Advances in Ll-nar Photography. — MM. Lcewy and 

 Puiseux recently communicated to the P.iris Academy a paper 

 on photographs of the moon, t.iken at the Paris Observatory, by 

 means of the great Condc' equatorial. Some of the photographs 

 have been enlarged by Dr. Weinek, and the enlargements seem 

 to have excelled in beauty and detail previous lunar pictures of a 

 similar kind. .\n examination of the photographs shows that not 



NO. 1313, VOL. 51] 



only c.in they be used to verify the general feature5ofthem')->n' 

 surface, as depicted upon the most recent and complete lunar 

 maps, but they also show a number of details and small craters 

 which so far have been omitted from such maps. There are, of 

 course, a number of causes which prevent a single photograph 

 from being an ideal representation of a celestial object, and 

 enlargements are usually regarded with a certain amount of 

 suspicion, for there is always a possibility that interesting forma- 

 tions will be unconsciously manufactured in the process. MM. 

 I^cowy and Puiseux know this as well as anyone ; nevertheless, 

 they find that the enlargements undoubtedly reveal new features, 

 and definitely determine the existence of several contested 

 objects. They think an instrument of long focus is essential 

 for the best results, and that the enlargements should not be 

 carried beyond twenty or thirty diameters. One object upon 

 which the photographs have thrown light is the small isolated 

 crater Linnc, situated in the middle of the Sea of Senenity. 

 According to Shroeter, Beer, Maedler, Lohrmann, and other 

 selenographers, this crater was distinctly visible up 10 1866, 

 when Schmidt announced its disappearance. It was afterwards 

 discovered again, but was much smaller than when described 

 and figured by Beer and Maedler. Dr. Weinek finds that the ob- 

 ject appears upon a plate taken on March 14, but only one kilo- 

 metre in diameter — that is, about one-tenth the value assigned 

 to it by the earlier observers. The crater has also been found 

 on other plates, and Sig. Schiaparelli has testified to its reality. 

 Four new objects — three craters, and the fourth an isolated 

 elevation of some kind — have been found in the plain which 

 extends to the south of Ariadaeus, between the bright crater- 

 plain Cayley and the Silberschlag crater. Ten new craters can 

 be detected in the typical walled plain Albategnius. All the 

 rills observed to the west of Triesnecker can be seen to extend 

 beyond the limits previously assigned to them, and to con- 

 nect Ariadaeus, Hyginus, and Triesnecker with interlacing 

 clefts. Judging from these results, we cannot but conclude that 

 the photographs represent real advances in lunar photography. 



CoMETARV Ephemerides.— The following ephemeris for 

 Encke's comet is in continuation of that given on November 22, 

 ■and is due to Dr. O. Backlund. M. Schulhof's ephemeris, in 

 the Aslronomischc Naclirichten, No. 3267, is used for Swifi's 

 comet : — 



It will be seen from these ephemerides that the two comets 

 are in the same region of the sky, both being a few degrees 

 south of Pegasus. Observations of the comets are greatly needed. 



Russian Astronomical OnsERV.\TioNs. -^ The latest 

 Bulletin (vol. XXXV. No. 4) of the Imperial Academy of Sciences 

 at St. Petersburg is almost entirely devoted to astronomical 

 papers. K. Lindemann contributes a discussion of the visual 

 and photographic magnitudes of Nova Auriga;, and gives a 

 light curve extending from December 10, 1891, to April 13, 

 1S92. N. Nyren discusses the observations made at Pulkov,^ 

 with the vertical circle, between 1882 and 1891, from the point 

 of view of variations of latitude. The curves derived from ihe 

 observations indicate that the interval between two maxima is 

 433 d.iys. and between two minima, 434 days. .\s to ihe 

 amplitude of the variation, though no definitive result is 

 stated, the value of the radius of the circle described by the 

 instantaneous pole appears to be 0"'I45, and the direction of 



