402 



NA TURE 



[February 22, 1906 



070 km. and 2000 km., the mean diameter being i"-g, or 

 about 1400 km. Figs. 2 and 3 illustrate the type of photo- 

 graph on which the measures were made. These were 

 taken with an interval of twenty-five seconds, and even 

 a cursory glance will show that during that time the 

 arrangement and forms of the granules have altered con- 

 siderably ; on this scale the diameter of the sun would 

 be about 3 metres. 



It seems probable that these researches will lead to most 

 important conclusions concerning the nature and the perio- 

 dicity of the changes in the granules themselves, their 

 influence on the solar spots and faculae, and, in general, to 

 the resolution of many outstanding problems concerning 

 the nature and action of the photosphere, which are at 

 present unsolved. Prof. Hansky intends, therefore, to 

 pursue this line of research, but, as he points out, it will 

 only be during the comparatively rare moments of atmo- 

 spheric calm, and with such a powerful equipment as he 

 now possesses, that fruitful results are likely to be obtained. 

 In any case, he is to be warmly congratulated upon those 

 he has already published. W. E. Rolstox. 



PRACTICAL SCIENCE FOR SCHOOLS. 1 

 pROF. PERRY said that in the early days of the society, 

 ■*■ when he had the honour of acting as a secretary, and 

 when Guthrie and Foster, Kelvin and Fitzgerald were 

 presidents, no presidential addresses were delivered, and 

 he questioned whether we were not overdoing the business 

 of requiring general addresses, which must almost always 

 have as their theme the progress of science. Seldom did 

 we find in such addresses new accounts of important 

 original work, and he felt the inappropriateness of such 

 an address in speaking before a society the Proceedings of 

 which were more intense with original work of the best 

 kind than any other society known to him with the ex- 

 ception oi the Royal Society. He thought that every young 

 reader of a paper before a scientific society made the mis- 

 take of assuming that his audience knew a great deal of 

 the subject so familiar to himself, and hence his paper 

 was not understood. Writers of books on physics assume 

 their readers to be all truly logical students; they use 

 words properly in a technical sense, and forget that many 

 of their readers may use them in the newspaper writer's 

 sense. For example, take the expression " adiabatic ex- 

 pansion." There are people who insist on finding that 

 Rankine, Maxwell, and all others of our most exact writers 

 are not only inconsistent with one another in the use of 

 the expression, but that each is inconsistent with himself. 

 If a portion of fluid expands slowly without gain or loss 

 of heat, we know the way in which its p, v, and t alter as 

 it changes state; this was originally called "adiabatic 

 expansion," and the term has become a technical term 

 for that kind of alteration of />, v, and /, however it ma) 

 occur. Steam or air may be throttled through a non- 

 conducting reducing valve, but the expansion is not 

 adiabatic, although there is no gain or loss of heat. Steam 

 or air passing along a pipe with friction, if it can only 

 be made to lose heal through the metal of the pipe at 

 exactly the proper rale at every place, is expanding 

 adiabatically. When it is assumed that steam or air flows 

 without friction from a vessel through an orifice, it is 

 said that the expansion is adiabatic although it is rapid. 



Referring to the teaching of physics to students entering 

 upon the engineering profession, the president remarked 

 that such teaching was nearly always slipshod. Many men 

 enter a science college at the age of eighteen or more, 

 knowing nothing of physical science. In the case of a 

 great percentage of such men, it is impossible that they 

 should" acquire the scientific habit of thought. It is be- 

 cause so much of this kind of material is dealt with that 

 much of our teaching is slipshod. Every pupil entering 

 a science college ought to have been experimenting and 

 working graphically and numerically on physical science 

 problems from a very early age, and then our science 

 classes would deal with them in a scientific way. The 

 causes of the unfitness of the average student are two: one 

 that his instincts and habits of thought were not trained 



1 Abstract of the presidential address delivered before the Physical 

 Society on Febtuary 9, by Prof. J. Perry, F.R S. 



from early youth : the other that his teachers in science 

 college have absurd and uninteresting courses of study 

 lor him. In physics we are dealing with ideas which are 

 not familiar to young students, ideas which can only be- 

 come familiar in the laboratory. For example, such a 

 simple mathematical idea as that of a decimal cannot be 

 given in elementary schools in less than five or six years, 

 whereas one week of weighing and measuring would give 

 voting children familiarity and clear ideas about decimals. 

 Numerous examples could be given to prove that the prin- 

 ciples oi physics cannot be understood unless there has 

 been early experimental training, and this is the reason 

 why the professors of science in colleges of university 

 rank and the professors in technical colleges obtain such 

 poor reward lor their labour. Referring to the many 

 hundreds who every year take science degrees at the 

 universities, and the thousands who pass the London 

 I niversity matriculation examination, Prof. Perry re- 

 marked that if that was the standard of excellence of 

 those present, his address could serve no useful purpose. 

 Nothing ought to be compulsory in schools except the study 

 ol English and of natural science. The object of a 

 matriculation examination is to test whether a student 

 entering a college will be able to benefit by the course 

 1 1 - ud) there. The only language which ought to be 

 compulsory in the science department of a university is 

 English. A professor of science ought to be allowed to 

 teach his students in the way that seems best to him, and 

 he should examine his students himself. Hedge him round 

 with rules and regulations framed by boards of studies; 

 tie him down to a syllabus, and the work he will do 

 might be much better, certainly much more cheaply, done 

 1>\ a grinder at low wages. There is no one general 

 elementary course in physics which all students ought to 

 take; neither by their previous training nor from the uses 

 which they will make of the principles of physics are they 

 fit to be taught together. What is wanted is more classes, 

 more rooms, and more teachers. 



NO. 1895, v O L - 73] 



THE NEW ORLEANS MEETING OE THE 

 AMERICAN ASSOCIATION. 

 ""THE New Orleans meeting of the American Association 

 ^ lor the Advancement of Science, as stated in our 

 issue for January 25 (p. 303), began on December 29, 

 1005, and continued for five days. At a meeting of the 

 general committee it was decided to hold a special summer 

 meeting at Ithaca, New York, to dose on or before Jul) 3, 

 [906, and an ordinary winter meeting in New York City to 

 begin on December 27, 1906. The presidential an. I vice- 

 presidential addresses will be omitted at the summer meet- 

 ing and given at the winter meeting. The officer- electi 

 at 1 lie New Orleans meeting will, therefore, hold office 

 until tie' dose of the New lork meeting. Chicago was 

 recommended as the place of the winter meeting oi 0107 



The following officers were elected for the [thaca ami 

 New York Hirelings : — President : Dr. W. H. Welch, Balti- 

 more, Mel. Presidents of sections : A, Dr. Edward Kasiier, 

 New York City; B, Prof. W. C. Sabine, Cambridge, 

 Mass.; (', Mr. Clifford Richardson, New York City; 

 1), Mr. W. R. Warner, Cleveland, O. ; E, Prof. A. C. 

 Lane, Lansing, Mich. ; F, Prof. E. G. Conklin, Phila- 

 delphia, Pa. ; G, Dr. D. T. MacDougall, Washingti 

 [).('.; II, Prof. Hugo Munsterberg, Cambridge, Mass. 

 I, Mr. ('has. A. Conant, New York City; K, Dr. Simo - 

 Flexner, New York City. General secretary : Mr. John F. 

 Hayford, Washington, D.C. Secretary of council : Presi- 

 dent F. W. MiNair, Houghton, Mich. 



The following resolutions were adopted by the associ- 

 ation : — (1) That the association instructs its president and 

 secretary to communicate to the president of the Senate 

 and to the speaker of the House of Representatives of 

 the United States its strong conviction that Niagara Falls 

 should be preserved as a natural wonder, and further 

 expressing the earnest hope that the congress now in 

 session will take prompt and energetic action looking 

 toward an international consideration of the impending 

 danger to Niagara Falls. (2) An Appalachian Forest 

 Reserve. — That the association again respectfully calls. 

 attention to the rapid rate at which the forests of the 



