IATIONS FOR TIIK ADVANCEMENT OP SCIENCE. (Bitni,ii., 



27 



we may profitably restrict our attention on the 

 it ocraMon, and wherein we may see how 

 the leading principles that were proclaimed in 

 tliis city a hundred yean ago have germinated 

 and borne fruit all over the world." 



It is impossible to give the various points dis- 

 riis-ed by him, but the following is of special 

 iiitciT-t : " There is no reason to think that the 

 rate of organic evolution has ever seriously va- 

 ried ; ;it Icust no proof has been adduced of such 

 variation. Taken in connection with the testi- 

 mony of the sedimentary rocks, the inferences 

 deducible from fossils entirely bear out the opin- 

 ion that the building up of the stratified crust 

 of the earth has been extremelv gradual. If the 

 many thousands of years which have elapsed since 

 the fee Age have produced no appreciable modi- 

 fication of surviving plants and animals, how 

 vast a period must have been required for that 

 marvelous scheme of organic development which 

 is chronicled in the rocks ! After careful reflec- 

 tion on the subject, I affirm that the geological 

 record furnishes a mass of evidence which no 

 arguments drawn from other departments of 

 Nature can explain away, and which, it seems to 

 me, can not be satisfactorily interpreted save 

 with an allowance of time much beyond the 

 narrow limits which recent physical speculation 

 would concede." 



He closed with : " In this marvelous increase 

 of knowledge regarding the transformation of 

 the earth's surface, one of the most impressive 

 features is the power of perceiving the many 

 striking contrasts between the present and for- 

 mer aspects of topography and scenery. What 

 is seen by the bodily eye mountain, valley, or 

 plain serves but as a veil, beyond which, as we 

 raise it, visions of long-lost lands and seas rise 

 before us in a far-retreating vista. Pictures of 

 the most diverse and opposite character are be- 

 held, as it were, through each other, their linea- 

 ments subtly interwoven and even their most 

 vivid contrasts subdued into one blended har- 

 mony. On every side of us rise the most con- 

 vincing proofs of the reality and potency of that 

 ceaseless sculpture by which the elements of 

 landscape have been carved into their present 

 shapes. Turn where we may, our eyes rest on 

 hills that project above the lowland, not because 

 they have been upheaved into these positions, 

 but because their stubborn materials nave ena- 

 bled them letter to withstand the degradation 

 which has worn down the softer strata into the 

 plains around them. Inch by inch the surface 

 of the land has been lowered, and each hard 

 rock successively laid bare has communicated its 

 own characteristics of form and color to the 

 scenery." 



A. Mathematics and Physics. The presiding 

 officer of this section, Prof. Arthur Schuster, 

 Ph. D., F. R. S., F. R. A. S.. opened his address 

 with a brief review of the progress of physical 

 science, in the course of which he said : " No 

 event has ever happened so striking as that which 

 took place on Jan. 1, when the mantle of Sir 

 William Thomson fell on the infant Lord Kel- 

 vin. Those who have attended these meetings 

 will feel with me that the honor done to our 

 foremost representative an honor which has 

 been a source of pride and satisfaction to every 

 student of science could not altogether remain 



unnoticed in the section which owes him HO 

 much." 



He discussed somewhat fully the subjects of 

 moving matter and electrical action, and the sun 

 spots and the atmosphere. In closing, he said : 

 "The statement of a problem occasionally helps 

 to clear it up, and I may be allowed, therefore, 

 to put before you some questions the solution of 

 which seems not beyond the reach of our pow- 

 ers: 1. Is every large rotating mass a magnet 1 

 If it is, the sun must be a powerful magnet. 

 The effect of a magnet on the discharge is known, 

 and careful investigations of the streamers of 

 the solar corona ought to give an answer to the 

 question which I have put. 2. Is there sufficient 

 matter in interplanetary space to make it a con- 

 ductor of electricity? Its conductivity can only 

 be small, for otherwise the earth would gradual- 

 ly set itself to revolve about its magnetic pole. 

 Suppose the electric resistance of interplanetary 

 space to be so great that no appreciable change 

 in the earth's axis of rotation could have taken 

 place within historical times, is it not possible that 

 the currents induced in planetary space by the 

 earth's revolution may, by their electro-magnetic 

 action, cause the secular variation of terrestrial 

 magnetism f 3. What is a sun spot! The gen- 

 eral appearance of a sun spot does not show 

 any marked cyclonic motion, though what we 

 see is really determined by the distribution of 

 temperature, and not by the lines of flow. But 

 a number of cyclones clustering together like 

 the sun spots in a group should move round 

 each other in a definite way, and it seems to me 

 that the close study of the relative positions of 

 a group of spots should give decisive evidence 

 for or against the cyclone theory. 4. If the spot 

 is not due to cyclonic motion, is it not possible 

 that electric discharges setting out from the sun 

 and accelerating artificially evaporation at the 

 sun's surface might cool those parts from which 

 the discharge starts, and thus produce a sun 

 spot? 5. May not the periodicity of sun spots 

 and the connection between two such dissimilar 

 phenomena as spots on the sun and magnetic 

 disturbances on the earth be due to a periodical- 

 ly recurring increase in the electric conductivity 

 of the parts of space surrounding the snnf 6. 

 What causes the anomalous law of rotation of 

 the solar photosphere 1" 



Several very important subjects were discussed 

 before this section, including one "On a Nation- 

 al Physical Laboratory," in which several distin- 

 guished German physicists took part, among 

 whom was Hermann L. F. von Helmholtz, of the 

 University of Berlin. Another discussion was 

 " On Nomenclature of Units," and reports " On 

 Underground Temperature." "On the Discharge 

 of Electricity from Points," and " On Electrical 

 Standards " were discussed. The important pa- 

 pers included " Wire Standards of Electrical Re- 

 sistance." by Dr. Lindeck; "On the Clark Cell." 

 by Dr. Kahle ; " Preliminary Accounts of Oceanic 

 Circulation, based on the' Challenger Observa- 

 tions." by Dr. A. Buchan: " Physical Condition 

 of the Waters of the English Channel," by II. V. 

 Pickson ; "On Primary and Secondary Cells in 

 which the Electrolyte is a Gas," by Dr. Arthur 

 Sdni-ter: "On Leaky Magnetic Circuits," by Dr. 

 DuBois; "Experiments on the Electrical Resist- 

 ance of Metallic Powders," by Dr. Dawson Tur- 



