Sept. 15, 1881] 



NA TURE 



461 



It is needless to say that no spectrum was observed. These 

 facts appear to be utterly irreconcilable with the conclusion 

 drawn by Messrs. Young and Forbes. 



Albert A. Michelson 

 Schluchsce, Piusiia, August 28 



Salmon in Preserved Rivers 

 Having resided for some time lately near one of our salmon 

 rivers which is at present preserved by a club, I have at different 

 times had conversations with men who kr.ew it before its .'O- 

 called preservation. They all say that when they were allowed 

 to fish when aiid huw they pleased, the lupply of fish Mas much 

 better in regard both to size and cjuaiitity. They account for it 

 in the following manner :— Firstly, when the river v as free, the 

 people living near used to make spawning-beds for the fiJi, by 

 placing large stones across the river and throwing gravel where 

 deficient, and where gravel w as naturally they used to loosen it \\ ith 

 forks and remove the large stones. Seccndly, they used to watch 

 the fish at spawning lime, and catch and kill all very large fish, 

 say about 16 to 30 1' s. weight, after ihty had partially or wholly 

 finished f pawning, as they say the large fish destroy the sahnon 

 fry. Neither this nor the formation of spawning-beds is done 

 at present. Would the above reasons account for the diminution 

 in the size a .d number of salmon caught in our rivers? The 

 diminution, in the river I speak of, cannot be accounted for by 

 pollution, as the nuiuber of houses near enough to send their 

 drainage into the river is too ;mall to affect it, and as the river 

 has a very quick fall and rocky bed, it is subject to such very 

 rapid rises and fall^ in quantity of water that would prevent any 

 settlement of noxious sei iment. F. C. S. 



New Seismometer 



In Naturf, vo!. xxiv. p. 113, thue is a notice of a new seis- 

 raometer which has several advantages claimed for it. Might I 

 suggest what seems an obvious and impoitant improvement? As 

 a rule pendulums cannot record vertical or oblique motions, and 

 yet these are often the m^.t necessary and valuable to record. 

 I. To do this, and yet as easily allow of lateral registration, I 

 would say, support a heavy (leaden) ball of some 100 lbs. by a 30 

 or 40 feet spiml or rubber spring <■. f suitable strength. It will be 

 found that a very con iderable amount of vertical play can take 

 place, especially vei tical cffor', ere the ball can be affected, and 

 that lateral play of the support will produce very little effect 

 indeed, unless, as is most unlikely, the motion is prolonged and 

 is continuous in one direction. 2. Around the sphere, and at a 

 very short distance from its surface, radial rods actuated like the 

 key-plugs of a cornet are supported, say at every 30° all ov^'r 

 the surface, contact with any one ( f which w ill electrically record 

 timi\ and the pencil attached to the plmiger record distance of 

 stroke on revolving paper attached to plunger-tube. 



Asani, July 6 S. E. Peal 



THE BRITISH ASSOCIATION 

 'X'HE actual number of persons who attended the York 

 *■ Meeting of the British Association, as announced at 

 the last meeting of the General Committee, w-as 2556; 

 divided between 272 old life-members, 27 new life-mem- 

 bers, 312 old annual members, 175 new annual members, 

 1232 associates, 51-I. ladies, and 24 foreigners. The seven 

 previous occasions on which this number has been ex- 

 ceeded were: — Newcastle-on-Tyne, 1863 (3335); Man- 

 chester, 1861 (3138); Liverpool, 1870(2878); Bath, 1864 

 (2802); Glasgow, 1S76 (2774); Dublin, 187S (2578); 

 Aberdeen, 1859(2564). The number fell below 1000 at 

 Cambridge, Pl\ mouth, Southampton, Ipswich, Hull, and 

 Swansea. 12S0/. were paid out by the Council for scien- 

 tific purposes alter the hist meeting, a larger sum than on 

 any occasion since 1873 ; while between 1873 and 1861 

 that sum was always exceeded, and at Norwich, in 1868, 

 it amounted to 1940/. 



The following foreigners were present at the meet- 

 ing :— Professrs Barker of Pennsylvania; Bergeron, 

 Paris ; Bojanowski ; Carbonnelle, Brussels ; Chemin, 

 Paris ; Craig, Johns Hopkins University, U.S. ; Dohrn, 

 Naples ; Eads, St. Louis, U.S. ; Gariel, Paris ; Dr. Asa 



Gray, Harvard University ; Halphen, Paris ; Dr. Edivin 

 Hall, Baltimore, U.S.; Hubrecht, Leyden; Prof W. W. 

 Johnson, .Annapolis, U.S. ; Prof. O. C. Mar^h, Yale 

 College ; Moser, Berlin ; Prof. H. A. Rowland, Balti- 

 more; Stephanos, Paris ; Sturm, Miinster, Westphalia ; 

 Prof. H. M. Whitney, Beloit College, Wisconsin, U.S. .A.. 



We ought to have stated in our report of the doings of 

 the Association in our last number, that Prof. Hu.vley's 

 lecture on Paleontology, which we gave in the same 

 number, was delivered on the evening of Friday the 9ih. 



Nearly 350 papers or reports were read before the 

 several sections. Of these the Physical and Mathe- 

 matical Section received 89 ; the Chemical Section 49 ; 

 Geology 59; Biology 79; Geography 16; Economic 

 Science and Statistics 26 ; and Mechanical Science 29. 

 Of the papers in Section A 23 related to Electricity ; 2 1 

 were Mathematical ; Cptics claimed 12 ; Meteorology 11 ; 

 Astronomy and Physical Geogr.phy 12 ; Heat 5 ; and 

 miscellaneous physical subjects 5. Cf course promineiit 

 subjects of interest were electric lighting, electric mea- 

 surement^, and Faure's cells. Such subjects were tho- 

 roughly ventilated by discussions both in Section and 

 Committee, and more intimately during the thousand and 

 one opportunities for interchange of ideas which occurrccl 

 in the afternoon and evening. .Again, the stoiage of 

 energy, the nature of meteoric dust, the existence of 

 intra-Mercurial planets, the lunar disturbance of gravity, 

 the nature of colours, and the contact theory were 

 each severally discussed. Among the 49 Chemical 

 papers several theoretical matters were introduced — 

 specially the atomic theory, chemical nomenclature, 

 vapour densities, molecular weights, MendelettT's law, 

 and molecular attraction ; processes of analysis and 

 technical operations were described, and new experi- 

 ments were explained. Of course a good deal of the 

 geological work bore reference to Yorkshire, especially to 

 the evidences of glacial action which it presents. The 

 geological papers were of a very general and interesting 

 character, and embraced every branch c-f the subject, 

 from the vulcanology of Japan to the minerals found at 

 Laurium, and from the Cheshire salt beds to the evolution 

 of the Plesiosaurus. Section D furnished a larger number 

 of papers than any other Section except .^, but we must 

 bear in mind that it really consists of three sub-sections, 

 devoted respectively to Zoology and Botany, Anatomy and 

 Physiology, and to Anthropology. The latter subject 1 as 

 developed extraordinarily, more than half the papers con- 

 tributed to the Section w^ere read before this Sub-Sectior. 

 The report of the Anthropometric Committee, which 

 evoked a good deal of discussion, was read in the Section 

 of Economic Science and Statistics. In this section Mr. 

 Grant Duff delivered a very able address, which was 

 warmly received. A tendency to introduce matter which 

 has a political bearing and which may be discussed from 

 a political standpoint is sometimes apparent in this 

 section, and should be carefully guarded against by tl:e 

 Committee. The Mechanical Section furnished some 

 important reports on patet.t laws, wind pressure, tides in 

 the English Channel, and the steering of screw steamers. 

 Here also were papers on the different forms of electric 

 lamp, the electrical transmission of force, and the 

 illumination of lighthouses. 



Thus it will be seen that all the prominent subjects of 

 science have received their share of attention, and at the 

 hands of one or other of the sections have been either 

 expanded or discussed. The interchange of ideas has 

 been incessantly going on, and many men have become 

 acciuainted who might otherwise have remained unknown 

 to each other for years. Some 500 scientific men have 

 been gathered together from various parts of the British 

 Islands ; and some 2000 persons have been brought face 

 to face with the burning scientific questions of the day, 

 and have had new interests awaV.ened, or old knowledge 

 resuscitated. There can be little doubt as to the 



