A'^ TURK 



lMav 



2, 189: 



interjected a doubt, Imt next day 1 carefully examined a large 

 number of specimens here with a member of my staff, and we 

 totally faile<l to confirm Mr. Bateson"s statement.' 



\V. T. Thisei.ton-Dver. 

 Royal Cardens. Ke», April 29. 



The Unit of Heat. 



Mr. CiRiFKlTHS. in a recent communication lo the Royal 

 Society, has called attention to the indefiniteness attending our 

 present knowledge of the heat unit. In this connection I would 

 wish to suggest — what indeed has long been present in my mind 

 — that a unit of heat oiher than the present calorie is desirable. 

 The present thermal unit is highly arbitrary, as well as most 

 difficult of verification. This is true, whether we take the 

 temperature at which the calorie is to be measured as 4" C. or 

 15° C. or as the tem|H;rature of minimum specific heat of water. 

 The caloric owes its |ierpetuation to the method of mixtures — a 

 Jaborious and inaccurate method of calorimetry — and dates from 

 j» period when the variations in the specific heat of water were 

 not held of account. 



If we do .adhere lo a s(H;cific heat of water calorie, it will be 

 necessary to proceed as in the determination of the standard 

 metre ; obtain the more or less inaccurate mea.sureof the primary 

 unit in terms of some more accessible quantity. 



My suggestion is that we start with an accessible unit. I think 

 the latent heat of steam at the standard pressure has first claim. 

 One gramme of saturated steam at 760 m.m. might be assumed 

 to give up the unit quantity of heat in becoming water, without 

 change of tem|KTature. This unit might be called a ihenii, in 

 order to avoid confusion with the existijig unit. The specific heat 

 of water would then stand as about I '8 milli-therms. The larger 

 value of the new unit commends itself as being more applicable 

 lo the problems of applied science ; which, indeed, may be 

 inferred from the fact that engineers often understand by the term 

 calorie the kilogramme-ilegree. 



I am aware that the change proposed is a radical one ; but an 

 appreciable change is letter than a vexatious correction, and we 

 know now that revision and change are inevitable. 



In the definition of the proposed unit we repla e the unreliable 

 thermometer by one of the most trustworthy of instruments — the 

 barometer : and our quantities of heat may be determined by the 

 chemical balance, and, at 760 m.m., read directly upon the 

 weights. \Vc are sure of the purity of the material. 



Trinity College, Dublin. J. Jni v. 



The Study of Earthquakes in the South-East of 

 Europe. 



In two recent notes in Natl'RK (vol. li. pp. 180, 468) atten- 

 tion has l)een ilrawn to the foundation by the Ottoman govern- 

 ment of a geixlynamic section of the Imperial Meteorological 

 Olservatory at Constantinople. The new department has been 

 placcfl under the direction of l>r. ("■. .\gamennone, who for 

 several years held a similar office at Rome, and who is well 

 known lo seismologists for the valuable work performed by him 

 in Italy. 



Not content with the foundation of a seismological observa- 

 tory, Dr. Agamennone has also undertaken the organisation of 

 earthquake studies Ihroughoiil the Ottoman Kmpire, and he is 

 anxious lo extend this very important branch of his work so as 

 to include the entire district within and Ixirdering the eastern 

 end of the Mediterranean. .\s there must be many readers of 

 Nature who are able, either directly or indirectly, lo aid him 

 in this atlempt, I should Im; grateful if you would allow me 

 lo recommend it to their attention ami support. Dr. Agamen- 

 nonc's address Ls " Obscrvaloirc Im|KTiale Meteorologique, 

 Constantinople (Pera)." 



That OIK- • f '!■■ ',..••• seismic regions of the glolM." should at 

 last iiltr.icl r I sludy it deserves, and that the initia- 



tion of the I ^ ' rvations should have fallen into hands 



so experienced and capible, will Ije mailers of gratification to 

 lho<e who arc inlcresled in the progress of seismology. No 

 1 ' !■ would it be thai all the results of such observa- 



' >>c contained in the pages of a single journal, and 



!<.. 1 ' '■ 'iMi of a monthly seismic bulletin, 



of whi : > h.ive alreafly been issued, is an 



ad'liti.: ■nccnlralion of records from the 



'liffercnl countries concerned in the Turkish Office. 



Birmin'^h^m. April 19. ClIAKLES DavisoN. 



I Tl, 



Ihrriih 

 " Aniiiui^- 



NO. 1331. VOL. 52] 



n the frrnl form in the foliage of 

 principles laid down hy D.irwin in 



" vol. ii, pp. 3I7'»3D. 



Uniformitarianism in Geolog;y. 



In reference to I'rof. Judd"s excellent statement of the posirioa 

 of the uniformitarian, allow me to call attention to an arg<nnen« 

 which tends to show that, so far as earthquakes and volcanic 

 eruptions are concerned, catastrophes may be of greater magni- 

 tude now than in earlier geologic times. 



The \nolence of an explosion will depend largely on thi 

 amount of confinement and pressure to which the exploding 

 compounds are .subject, as well shown in the case of Kilauea 

 where there is a constantly open vent and no violent eruptions 

 as contrasted with the numerous catastrophic explosions of loni; 

 dormant volcanoes whose vents hati become sealed up with eort-- 

 of solid lava. Kut it is admitted that the crust <^f tlie earth h.i^ 

 been growing thicker during all geological time. It is thcrefort 

 almost certain that, in the remoter epochs volcanic phenomena 

 were more frequent but less violent than they have become no" 

 that the crust is thicker, .ind, in its lower ])ortions, at all event>. 

 denser and more consolidated. The usual argument, that, l>ecausi 

 the interic^r of the earth was somewhat hotter in early tinit.-- 

 therefore volcanic phenomena were more violent, appears to mc 

 to be entirely fallacious. The liquid matter immediately belo\s 

 the crust would have been at the .same temperature then as it i> 

 now : and if there were a more abuntlant sup]>ly of aqueous va|K)Ui 

 and other gases, the thinner and more permeable crust wouM 

 have allowed of their constant and comparatively easy esca|)e. 



I tlo not remember to have seen this consideration referred I" 

 in any discussion of the question, and I thereft>re submit tlu 

 argument to the judgment of physical geologists. 



.\i.KRKn K. Wai.ijwk. 



Research in Education. 



I'KOK. .Vrms'I RON(/s trenchant indictment ol the |>riseiu 

 methods of leaching science, is a little too much akin lo Carlyle^ 

 fulminations against things in general — destructive but not con- 

 structive. Probably all good teachers are agreed upon the [ler- 

 nicious futility of the text-book and lecture-room cram system, 

 and are in thorough accord as to the educational value of 

 practical w-ork ; and are waiting only to learn or discover the 

 best system of em|ik>\'ing it. To this end destructive criticism Itelps 

 but little. What is wanletl is some definite scheme of work cim- 

 strucledby mastersof practical instruction. I'rof. .\rnislrong iIck > 

 certainly advocate what may be termed the " research method "" : 

 but it does not elucidate the question much, for it is difficult in 

 understand how far he would extend this method. Would he. 

 for instance, never mention Dalttm's laws to students until, by \\ 

 series of analyses, they were in a position lo discover them fiM 

 themselves? Or in the case <jf specific heat, how much inforitia 

 tion should be given before the beginners are set to investigate 

 the phenomena alone ? There are two ways of learning practi- 

 cally physical and chemical truths, either by repealing methoils 

 which have been explained and demonstrated, and then verifying 

 e.ach step by .actual contact with real objects, and so acquiring 

 real knowledge of fact and the apjilication of theory, or by 

 struggling lo the truth by a process of trial and error. That the 

 latter process, when successful, is the more stimulating to the in 

 lellect may be admitted, but that it is practically |>(>ssilile must Ik 

 iloubted. In introducing any new subject to the mind, ^urely 

 broad outlines should be giveti first, antl details filled in .after- 

 wards ; observation re<|uires teaching as much as any other facidl v. 

 Tyndall tells this story of Karaday. .\s Tyndall k;ls about lu 

 show the l.itler an experiment, Karaday laid his hand on lii> 

 shoulder and said, " Walt a minute ; what am I lo look for ? " Tlu 

 application is plain even Karaday fell the advantage of having 

 ihe observer fore-armed. 



Heginners know nr)l what loobserve, and cannot fashion experi- 

 ments for themselves, and therefore it seems more rational, that 

 students should have Ihe recogniseil methods of science explained 

 and demonstrated lo them, and then be caused lo repeal the 

 nccessar)' operations practically, numerical rletails being varied 

 as in mathematical exercises. \\"la'ii tiius equi]i|>ecl with sound 

 Iheorelical knowledge and fair manipulative cleMerity. they wiU 

 Ix; in a position to embark upon "research'' ; for Ihey will Ihei 

 have nc(|uired some power of observation, .accuracy, and the 

 faculty of making inferences. The "research method" ah 

 initio ap|>ears like an attempt to teach a child to read 

 before he knows his leltcr.s. I am fully conscious of niT 

 aud.icity in venturing into the lists, and am not ignorant 

 of ihr sort of full, \ili.. ■■ iiiadlv rush wlicrt- .ingi-ls fc-.ir \u 



