572 



NA rURE 



[April 15, I J 



to extend our inquiries. In bringing our labours to a termina- 

 tion, we feel very strongly that many of the subjects with which 

 we have dealt need much further elucidation by perseverance in 

 experimental research of the kind which we have pursued We 

 are convinced that if the worlc which we are relinquishing were 

 continued, the knowledge of the conditions to be fulfilled for 

 securing safety from preventable disasters, and the development of 

 resources and appliances calculated to promote the fulfilment of 

 those conditions, could still be much advanced. It is moreover 

 certain that new subjects for inquiry connected with the safe 

 working of coal-mmes must continue to present themselves, as 

 has been the case during our seven years' experience. These 

 considerations have impressed upon us the need for the official 

 estal^lishment of some permanent arrangement by which the 

 continuous pursuit of this highly important class of work would 

 be secured, and by which, also, the merits of suggestions and 

 inventions presenting themselves from time to time would be in- 

 vestigated properly and thoroughly, and dealt with authoritatively 

 \ye consider, moreover, that the complete investigation of coal- 

 mme disasters would be greatly promoted if the arrangements 

 to which we have referred were utilised systematically, in con- 

 nection with the usual official inquiries, in dealing with the diffi- 

 d^saslers ' ^"^""y ""''''' '" <='»<:idating the causes of these 



Warington \V. Smyth. Thos. Burt. 



Crawford and Balcarres. R. B. Clifton 



v^T'^f Elliot. W. Thomas Lewis. 



T ;^'"'''" Lindsay Wood. 



John Tyndall. 



March 15, 1886 



SCIENTIFIC SERIALS 

 In the Jour,ial of Bola>,y for March Mr. G. A. Holt de- 

 scribes and ligures a species of moss, Thaiitnium angusUfolium, 

 not on y new to Britain, but new to science. It was found 

 sparingly in Derby, hire. -\fr. J. G. Baker concludes his com- 

 parison of the British an I Continental forms of the difficult 

 genus Riibus. 



Proccciings of the Liimait Society of Nno South IValea, vol. 

 X. parts, Sydney, December 21, iSSs.-This part contains the 

 proceedings of this most energetic Society for July, August, and 

 September, 1SS5, and memoirs by the following : -Dr. R. von 

 Lendenfeld, monograph of the Australian sponges, part 5 (plates 

 ^ i?^'',- ' ™, Aulenina:, order 3, the Ceraospongia;, Halme, 

 Aphrodite, Aulena, and Halmopses are established as new genera, 

 patt 6 (plates 36-38), on the genus Euspongia.— On a spon"e 

 destructive to oyster culture in the Clarence River, a new species of 

 Chalinula;.— Addendum to the Australian sponges. —Addendum 

 to the Australian Hydromedusce.-Note on the Glacial period 

 in Australia. -Vy. A. Haswell, M. A., jottings from the Biological 

 Laboratory of the Sydney University, on an Australian species 

 ot Uonellia ; on a greater respiration in fresh-water turtles, 

 i^rom observations on the Australian Chdodina lomricollis thinks 

 the pheiiomena described by S. H. Gage as auxiliary respiration 

 extremely improbable and that the Chelonian can bear with 

 impunity being deprived of oxygen for lengthened periods ; but 

 the facts recorded by Simon and Sus.anne Gage in the March 

 I8i>5 number of the American Natu-alist cmno\. thus be inter- 

 preted. —Lapt. Hutton, on the supposed Glacial period in Aus- 

 Ju »; , ■ '''' Miklouho-Maclay, plants used by the natives of 

 the Macleay Coast, named by Baron Miiller.— George Masters, 

 catalogue of the hitherto-described Coleoptera of Australia, 

 part I, Ucindehda; and Carabidos (960 species enumerated).— 

 J. Uouglas-Ogdby, three new fishes from Port Jackson ; notes on 

 on-B-^"' """" °^ '*°'"'^ Australian sharks and rays.— A. Sidney 

 UlliH, new species of Australian Coleoptera belonging to the 

 genera Lacordairia, Xanthophaja, Plagioteium, Catosiopus, and 

 Kcysodes — W. Macleay, on a new genus (Phalacrognathus) of 

 the subfamily Lamprimides.— Rev. Dr. Wools, on doable 

 nowers. --K. H. Bennettt, remarks on the decay of certain 

 species of tucalyptus. The species were almost without excep- 

 tion .&. mdlidora and E. roslratu, and the cause is ascribed to 

 the enormous increase in the numbers of the opossums. Some 

 laea of the number of this animal in a portion of Gipps' Land 

 may be had from the fact that four men in a short time procured 

 a quarter of a million of skins. 



liivista Srientifico-Inluslriale, February 28.- Description of 

 a new telescope, the "plesiotelescope," by Prof. Nicodemo 



Jadanza. This is an astronomical instrument intended for the 

 study of near and distant objects. It is constructed with an 

 achromatic objective, M, to the second focus of which is attached 

 a second lens, n, at a less focal distance than that of the lens M. 

 i hese two lenses form a compound objective, which brings into 

 view objects at short and great distances. -A new application 

 of electrolysis, by G. F. The anonymous author describes a 

 process for producmg damascened work rapidly and econo- 

 mically by electrolysis.— Note on the explosion of boilers in 

 steam-engines by Prof. Giovanni Luvini. The author traces 

 the bursting of boilers to their chief causes, suggests a practical 

 remedy, and offers some remarks on a means of generating 

 steam with a saving of fuel.— A description of Prof. E. Lommel's 

 aerostatic scales for determining the specific weight of gases, by 



Bulletin lie VAcadhnie Royale de Belgique, January.- Descrip- 

 tion of some ciystals of calcite, by Prof. C. Casaro. The author 

 describes a first series of Belgian calcites, comprising the crys- 

 als found along the left bank of the Meuse and in some other 

 localities. These are reduced to thirty-two simple forms, of 

 which three are new. —On the difference of sea-level in 

 winter and summer, by Gen. Commines de Marsilly. It is 

 argued that the Polar seas must be higher in summer than in 

 "inter, when the accumulation of ice increases the salinity, 

 consequently also the density, of the water.— Note on the dis- 

 play of meteors observed throughout Belgium on November 27, 

 ibSS, by F. Fohe. The maximum of intensity was generally 

 alioiit 6 p.m., when as many as 155 meteors were observed in a 

 single minute at Louvain.— .A. contribution to the study of the 

 gerni-cell in the lower animal organisms, by C. Van Bambeke. 

 — On the coefficient of internal friction of fluids : determination 

 of Its variations according to temperature. Theoretical con- 

 siderations suggested by the observation of these variations, by 

 P. de Ileen. 



SOCIETIES AND ACADEMIES 



London 



Royal Society, March n.— "Qn Systems of Circles and 

 Spheres. By R. Lachlan, B.A., Fellow of Trinity College, 

 Cambridge. Communicated by Prof. A. Cayley, F.R.S. 



This memoir is an attempt to develop the ideas contained in 

 two papers to be found in the volume of " Clifford's Mathematical 

 Papers" (Macmillan, 1882), viz. "On Power Co-ordinates" 

 (pp. 546-55), and "On the Powers of Spheres" (pp. 332-36). 

 The conception of the " power o{ two circles," or spheres, as an 

 extension of Steiner's use of the "power of a point with respect 

 to a circle, ' is due to Darboux. 



The memoir is divided into three parts : Part I. consists of the 

 discussion of systems of circles in one plane; Part II. of systems 

 of circles on the surface of a sphere ; and Part III. of systems of 

 spheres. 



The power of two circles is defined to be the square of the 

 distance between their centres less the sum of the squares of their 

 radii. 



Denoting the power of the circles (i, 2) by it , it is proved 

 that the powers of any five circles (i, 2, 3, 4, 5) with respect to 

 any other circles (6, 7, 8, 9, 10) are connected by the relation— 



S. 6 5, 7 ■^s, 3 '^s, 9 

 which may be conveniently written — 



^/l. 2. 3, 4- SN_n 

 ''1,6,7,8,9, ioJ-°- 



This is the fundamental theorem of the paper ; it is shown that, 

 if the power of a straight line and a circle be defined as the 

 perpendicular from the centre of the circle on the straight line, 

 and the power of two straight lines as the cosine of the angle 

 between them, then the theorem is true if any circles of either 

 system be replaced by points, straight lines, or the line at 

 infinity. 



The general theorem is then applied to prove some properties 

 of special systems of circles, and more particularly those systems 



