Dec. 12, 1878] 



NATURE 



121 



History of the Speaking Telephone 



As the writer of the article on the history of the telephone, 

 to which so eminent an authority as Prof. Watson takes excep- 

 tion in the long and interesting letter he has contributed to your 

 columns, perhaps you will allow me to say a few words. Prof. 

 Watson expresses his " astonishment at the claim now made that 

 ' e (Mr. Gray) anticipated Mr. Bell in the invention of the 



peaking telephone," and speaks of the "erroneous statement of 

 acts" contained in the article in question (Nature, vol. xviii. 



. 696). Unfortunately Prof. Watson has not specified the 



atements which are erroneous, and appears to have overlooked 

 :,e fact that the article is a review of the works of Mr. Prescott 



.d M. dn Moncel on the telephone, and that the " statements of 

 acts" are chiefly quotations from those works. At the same time, 



-ing all the materials within my reach, careful inquiry had led me 

 J concur, and in that article I expressed my concurrence in the 

 following opinion, quoted from Count da Moncel's book : — "Si 

 M. Bell a ete le premier a construire et a rendre pratique le tele- 

 phone parlant, M. Elisha Grayavait le premier con9U leprincipe 

 de cet instrument." 



Gray and Bell were both exhibitors at the Philadelphia Exhi- 

 bition, and Prof. Watson, ^vl•iting as one of the judges of the 

 scientific instraments exhibited, shows that whilst Gray merely 

 submitted to the judges an apparatus for the multiple transmis- 

 sion of musical notes, and no speaking telephone. Bell not only 

 exhibited a speaking telephone, but towards the end of June 

 (1876) the judges. Prof. Watson and Sir William Thomson, 

 obtained with Bell's instrument the clearest evidence of the 

 electric transmission of speech ; ^ whereupon Mr. Gray was both 

 surprised and incredulous, and even after the publication of 

 Prof. Bell's discovery, he delivered a lecture exhibiting his 

 musical telephone, but making no mention of a speaking 

 telephone. 



If the Philadelphia Exhibition were the only means for scien- 

 tific publication during the year it^existed. Prof. Watson's letter 

 would effectually dispose of Gray's claim. An exhibition, how- 

 ever, is not the place for conceptions, but for accomplished 

 facts, and I believe no one denies that to Mr. Bell is due all 

 the credit of having been the first to construct, and that entirely 

 independently of Gray, an articulating electric telephone. 

 Gray's claim, as I take it, rests on his having registered in the 

 American Patent Office, on February 14, 1876, " a means of 

 transmitting and receiving vocal sounds telegraphically," and 

 the drawing he gives of his invention shows a correct apprecia- 

 tion of the true principle of an articulating telephone, to which 

 his previous researches had been gradually leading him. 



I should be sorry to appear in any way to depreciate the 

 splendid achievement of Prof. Bell through having referred to 

 other workers in the field of electric-telephony. In fact up to 

 tlie time the article in Nature appeared, I fear that, through 

 ignorance, I had done but scant justice to Mr. Gray, having 

 attributed the conception of the principle of an articulating tele- 

 phone solely to Prof. Graham Bell. 



There are two points in the history of the telephone upon 

 w hich I should be very glad to have authoritative information 

 from Prof. Watson or other of your American readers ; the first 

 relates to the claim made by Prof. Dolbear, and the second to the 

 introduction of the ferrotype diaphragm. W. F. Barrett 



Royal College of Science, Dublin, December 9 



The Formation of Mountains 



In the account of M. Favre's experiments in Nature vol 

 XIX. p. 103, I find the following passage :-"It is, in fact,' verj^ 

 probable that our globe is at the stage when, according to Elie 

 de Beaumont, ' the mean annual cooling of the mass exceeds 

 that of the surface, and exceeds it more and more.' It must 

 follow that the external strata of the globe, tending always to 

 rest on the internal parts, are wrinkled, folded, dislocated, de- 

 pressed at certain points, and elevated at others." 



The whole theory of these dislocations, &c., thus depends on 

 the assumption that the interior of the globe is coolin<^ more 

 rapidly than the crust. This has always seemed to me an im- 

 possibility, and even an absurdity, and I shall be very glad if 

 any of your correspondents will explain how it is possible. I 

 have always understood that the surface of the earth does not 



m^-i^™!^'*^"''^^™'''" ^^^'^' ^3'« <^f tf'e trial m question, which was 

 given as August la the artcle. 



now derive any appreciable portion of its heat from the in- 

 terior ; but if the interior is cooling rapidly, to what can it part 

 with its heat but to the crust ? Volcanoes and hot springs no 

 doubt allow a certain portion of heat to escape, but it most be 

 an infinitesimal part of the heat of the entire mass. If the 

 meaning of the statement is, that the heat received from the sun 

 now keeps the surface at a permanent mean temperature, quite 

 irrespective of central heat or cold, and that therefore the loss 

 of heat by volcanoes, &c., causes the centre to cool while the 

 cmst does not — this may be admitted, but it is doubtful whether 

 it can have any bearing on the effects observed. For, on this theory, 

 all the compression would take place in that shallow superficial 

 layer which is kept above its normal temperature by the sun's 

 radiation; and as we go back into past time this superficial layer 

 would be thinner and thinner. But all geological evidence goes 

 to show that folded and contorted rocks were subject to com- 

 pression at considerable depths ; and further, that such contor- 

 tion w as greater in comparatively early than in very late geo- 

 logical times — both facts directly opposed to the theory in 

 question. Will any one of our great physicists enlighten us ? 



Alfred R. Wallace 



After reading yovu: resume of Prof. Alphonse Favre's inter- 

 esting experiments on the formation of mountains by lateral 

 thrust, it occurred to me that it would be easy to devise a mode 

 of experimenting which would more nearly correspond with 

 what takes place in nature. In M. Favre's experiments the 

 lateral thrust was simply in one direction. In nattire it is in 

 aU directions. 



If a disk of india-rubber were stretched by means of a sted 

 ribbon bent into a circular spring, on letting the spring slowly recoil 

 there would be a lateral contraction of the india-rubber in all 

 directions. A layer of clay upon that disk would, I think, show- 

 not the transverse inequalities of M. Favre's drawings, but a 

 diversified unevenness more nearly resembling the actual surface 

 of the earth. ARTHUR RANSOM 



Leicester, December 



New Galvanometer for Strong Currents 



I OBSERVE in Nature (vol. xviii. p. 707) an article on a ne^v 

 galvanometer for strong currents by Mr. Eugen Obach. I pub- 

 lished a paper on the same form of galvanometer seven years 

 ago, and inclose a copy of my paper which was published in 

 the American Journal of Arts and Sciences, vol. ii., August, 

 1 87 1. John Trowbridge 



Harvard College, Cambridge, Mass., U.S.A., November 23 



Explanatory 



I must ask you, in common fairness, to allow me to protest 

 against P. G. T.'s mistaken statement (vol. xix. p. 71) respecting a 

 sentence which he quotes without the explanatory context. The 

 moving force exerted by the earth on the moon as a whole is of 

 course precisely equal to the moving force exerted by the moon on 

 the earth. I had not to learn this from P. G. T., but had said so in 

 so many words. But the moving force exerted by the earth on a 

 given amount of matter in the moon is eighty-one times greater 

 than the moving force exerted by the moon on an equal amount 

 of matter in the earth. P. G. T. will scarcely deny this, and 

 he cannot deny that the w hole statement from which he quotes 

 one sentence meant this, and this only. Nor, if he did, would 

 any one who has read the chapter on the moon's motions in my 

 treatise on the moon, believe such a statement. 



He quotes a passage from my last book without comment, 

 but, unfortunately, not without serious alteration. Apart from 

 the undue emphasis which he thus gives to certain parts of 

 it, the passage expresses my honest opinion. That I may be 

 mistaken is quite possible. Men are always misunderstanding 

 each other. If I find I have erred, I will acknowledge as 

 much. 



Until the word "heat " ceases to be used in common speech 

 in two senses, or I am shown that when used for "temperature" 

 (as when we say blood heat, boiling heat, a heat of 90" F., and 

 so forth), it can be understood to mean "caloric," I intend 

 always so to use it in familiar writing about science. I deliber- 

 ately struck out the word "temperature" wherever I had used 

 it, and replaced it by the word "heat," in the same way and for 

 the same reason that I often replace the word " velocity " by the 



