May 31, 1894J 



NA TURE 



119 



Committee by the Solar Physics Committee, and was 

 entrusted to Mr. Fowler, who took the photographs at the 

 African station. 



It also seemed desirable that a series of similar photographs 

 should be taken at another point on the line of totality, even 

 though an equally efficient instrument were not available. A 

 spectroscope with two 3-inch prisms of 60', used in conjunction 

 with a siderostat, accordingly formed part of the equipment of 

 the expedition to Brazil, and was placed in charge of Mr. 

 Shackleton. 



The present preliminary report is intended to indicate the 



kind of results obtained, and some of the photographs are 



reproduced for the information of those specially interested, as 



■ it will be some time before the complete reductions are ready 



for publication. 



The most conspicuous lines, or rather portions of circles, 

 seen in the photographs taken during totality, are the II and 

 K lines of calcium, and in these rays the images of the various 

 prominences are very clearly outlined. 



The lines of hydrogen, extending far into the ultra violet, 

 are also very prominent, and numerous other lines are seen in 

 addition. 



Isochromatic plates were used for some of the exposures, and 

 on some of these the ring formed by the characteristic line of 

 the coronal spectrum (1474 K) is clearly depicted, especially 

 in the Brazilian photographs. A comparison with the photo- 

 graphic records of the corona shows that the prismatic camera 

 has picked out the brightest parts of the corona in this way. 

 AH the photographs show a bright continuous spectrum from 

 the inner corona. 



"On the Leicester Earthquake of August 4, 1S93." By C. 

 Davison, M. .^.j King Edward's High School, Birmingham. 



On August 4, 1893, at 6.41 r.M., an earthquake of intensity 

 nearly equal to 6 (according to the Rossi-Forel scale) was felt 

 over the whole of Leicestershire and Rutland and in parts of all 

 the adjoining counties. The disturbed area was 58 miles long, 

 46 miles broad, and contained an area of about 2066 square 

 miles. The direction of the longer axis (about W. 40° N. and 

 E. 40° S. ) and the relative position of the isoseismal lines show 

 that the originating fault, if the earthquake were due to fault- 

 slipping, must run in about the direction indicated, passing 

 between Woodhouse Eaves and Markfield, and hading towards 

 the north-east. The anticlinal fault of Charnwood Forest, so 

 far as known, satisfies these conditions, and it is highly 

 probahle that the earthquake was caused by a slip of this fault ; 

 greatest in the neighbourhood of Woodhouse Eaves, and 

 gradually diminishing in amount in either direction, rather 

 rapidly towards the north-west and much more slowly towards 

 the south-east. The total length of the fault-slip may have 

 been as much as twelve miles or even more, and there can be 

 little doubt that it was continued for some distance under the 

 Triassic rocks on which Leicester is built. 



Royal Society, May 10.— "The Stresses and Strains in 

 Isotropic Elastic Solid Ellipsoids in Equilibrium under Bodily 

 Forces derivable from a Potential of the Second Degree." By 

 C. Chree, Superintendent of Kew Observatory. 



The problem solved in the present memoir, viz. that of an 

 isotropic elastic solid ellipsoid under the action of bodily forces 

 derived from a potential 



4(P.r--t-Qy--l-R5"), 

 is the most general case of equilibrium under forces derived 

 from a potential of the second degree. The above potential 

 covers forces arising from mutual gravitation or from rotation 

 about a principal axis in an ellipsoid of any shape. 



The solution obtained satisfies without limitation or assump- 1 

 tion of any kind all the elastic solid equations. It enables the : 

 variation in the effects of gravitation and rotation with the change 

 of shape of the ellipsoid to be completely traced. 



The results obtained for the very oblate and very oblong forms 

 seem to show that in many cases of bodily forces the assump- 

 tions usually made in the treatment of thin plates and long rods 

 would not be justified. 



By comparison with the author's previous researches, a close 

 similarity is shown to exist between the phenomena in rotating 

 flat ellipsoids and thin elliptic discs on the one hand, and 

 rotating elongated ellipsoids and long elliptic cylinders on the 

 other. 



Royal Society, May 24.—" On certain Functions connected 

 with Tesseral Harmonics, with Applications." By A. H. 



NO. 1283, VOL. 50] 



Leahy, late Fellow of Pembroke College, Cambridge, Pro- 

 fessor of Mathematics at Firth College, Sheffield. 



Royal Society. — Cornclion. — In the abstract of the paper 

 "On the Specific Heats of Gases" (Part III.), by J. Joly, 

 F.R.S., read (in place of the formula given) : — 



Cv = a -F 2(''(I00-C) H- 3<f (100-/)-. 



Royal Microscopical Society, May 16. — Mr. A. D. 

 Michael, President, in the chair. — Mr. C. Lees Curties ex- 

 hibited and described a microscope which had been specially 

 made for photographic purposes. The leading feature of the 

 instrument is that the nose-piece is removable, so that an 

 ordinary photographic lens can be substituted for the objective 

 if required. He also exhibited a new form of apparatus for 

 obtaining instantaneous photographs of objects under the micro- 

 scope ; as examples of what could be done with this apparatus, 

 he showed photo-micrographs of blood-corpuscles taken with 

 powers X 306 and 600 diameters, and also some low-power 

 photos of living specimensof io/ir^Mj with tentacles extended. 

 Dr. W. H. Dallinger thought the photomicrographs were 

 extremely good. He noted in the immediate vicinity of the 

 Lophopus, there were some vorticeliat!, and this suggested that it 

 might be possible to take them in the act of closing, so as to 

 get an idea how the movement was performed. — Mr. Shrubsole 

 said he had brought to the meeting a few living specimens of 

 Gromia, which were shown under the microscopes on the table. 

 One peculiarity of these specimens was that instead of possess- 

 ing but one aperture, there was a zone of small apertures round 

 a central one. This he thought was a good reason why this 

 object should be removed from the Monostomia. .-Vfter de- 

 scribing a naked rhizopod closely allied to IJeberkiihnia, and an 

 organism resembling Slupluarjella, Mr. Shrubsole said he had 

 on the previous day obtained from the water ofT Sheernesssome 

 masses of a dirty-looking substance containing all sorts of 

 forms of gelatinous objects, in which were imbedded a number 

 of granules ; they were the cause of what the fishermen called 

 "foul water," or "May water." They were only seen for 

 certain seasons and for a short time, and it would be an interest- 

 ing inquiry to find out what became of them. — Prof. jefTrey 

 Bell said that he had just been present at the annual inspection 

 of the Marine Biological Laboratory at Plymouth, and he found 

 that one of the greatest troubles there had been the condition 

 of the water. Only two fish had died during the last twelve 

 months, but the Director was desirous of obtaining information 

 as to the diatomaceous and desmidaceous condition of the 

 water in the tanks. Inquiries naturally suggesting themselves 

 would be what the organisms really were which caused this " foul 

 water"; was the "foul water" due to their presence, and 

 were they a great number of larva undergoing transformation ? — 

 Prof. Bell called attention to the three frames of photo-micro- 

 graphs which formed the Society's exhibit at the Chicago Exhi- 

 bition, and which h.ad just been returned. The Fellows would 

 have now the opportunity of seeing them and determining 

 whether they were worthy of the medal which they were told 

 had been awarded the Society. 



Quekett Microscopical Club, M.ay 18.— Mr. A. D.Michael, 

 Vice-President, in the chair. — Mr. C. L. Curties exhibited a new 

 instantaneous photo-micrographic apparatus, and explained the 

 method of using it. Some excellent pictures of pond-life, and 

 fresh human blood corpuscles, &c. , taken by this apparatus, were 

 h.anded round for inspection, and one group of Lophopus, fully ex- 

 tended, surrounded by vorticellae,was particularly admirable and 

 lifelike. The Chairman thought thisapparatus would be especially 

 valuable for obtaining representations of quickly-moving organ- 

 isms, which were almost impossible to draw in a natural way 

 because of their rapid volutions, and they might get composite 

 pictures which would throw some light on this difficult subject 

 of locomotion in minute animals, such as had been done by 

 Muybridge and others with the horse, for instance. — .Mr. G. 

 Western read some interesting notes of foreign rotifers which 

 had since been found in Britain, amongst them being Xotholca 

 heptOilon, Bipalptis vesieulosiis, C/tromogasttr testiulo, ^Ecistes 

 miicicola, and..^'. Socialis, Brachionus dorcas, and others, which 

 were accompanied by beautifully executed drawings by Mr. 

 Dixon-Nuttall. Mr. Western pointed out the uncertainty and 

 variability of many of the characters relied upon for specific, 

 and in some cases for generic, value, such as the presence or 

 absence of seta;, antennal appendages, or even of the eyes. 

 Mr. Michael said with regard to the eye he had frequently found 

 the same peculiarity among the Ilydrachnea or water-mites ; in 



