5IO 



NATURE 



[April 2^, 1878 



that I venture to differ from him, for it seems to me, 

 from dynamical considerations, that a second equal im- 

 pulse following a first, at some time within 306 days, 

 might either double the wabble, alter its amount, or 

 annihilate it, according to how it was timed to take 

 place. 



If I am correct in this view, I cannot but think that 

 the estimate of geological time falls to the ground. For 

 even if the elevation of continents took place impulsively, 

 we can have no possible data for judging of how the 

 earthquakes were timed with reference to the position 

 of the axis of rotation, and unless they were properly 

 timed the radius of the wabble could not increase ; and 

 the increase of the radius is, I imagine, essential to Dr. 

 Haughton's method. 



But if we set aside the impulsive theory of elevation, 

 the work contained in my paper, " On the Influence of 

 Geological Changes on the Earth's Axis of Rotation," 1 

 will be applicable ; for I there considered the effects of 

 a slow continuous elevation of continents. In that paper 

 I show that such a mode of elevation would set up a 

 wabble of 306 days' period in the earth's motion. But 

 this wabble is of quite a different character from that 

 contemplated by Dr. Haughton, for it is unsymmetrical, 

 so that the axis of rotation coincides with the axis of 

 figure every 306th day. 



By a very simple application of a formula given in that 

 paper, it will be found that, supposing the continuous 

 elevation to take place at such a rate that the axis of 

 rotation is 5 feet distant from that of figure when at 

 its greatest distance, then the axis of figure must be 

 travelling with reference to the solid earth at the rate of 

 -f^ of a second of arc per annum. Thus, in 19,200 years 

 it will have travelled over i""' or 69 miles. That is to say, 

 Europe- Asia might have been elevated in 19,200 years 

 without the axis of rotation ever having described a circle 

 of more than 5 feet in diameter. If the elevation were 

 then to stop suddenly a symmetrical wabble would be set 

 up (such as that considered by Dr. Haughton), and the 

 radius of this wabble could not be greater than 5 feet, and 

 might be zero, according to the exact time of the 

 stoppage. 



This investigation makes no reference whatever to the 

 effects of tidal friction, and there are certain considera- 

 tions which lead me to believe that even the above 

 estimate of time might be largely reduced. 



The conclusion at which I arrive therefore is that the 

 elevation of Europe and Asia might have taken place in 

 very much less than 20,000 years without leaving behind 

 any wabbling in the earth's motion traceable by astro- 

 nomical observations. Dr. Haughton's views, if generally 

 accepted, are of the very greatest interest to geologists, 

 and they therefore merit the strictest examination ; as I 

 have devoted a good deal of time to this subject I thought 

 it might perhaps be useful to write this note. Should my 

 present criticism be incorrect, there is little doubt but 

 that it will meet its just fate of refutation,^ 



G. H. Darwin 



EARLY ELECTRIC TELEPHONY 



TN 1 861 the first successful attempt at the construction 

 •»■ of an electric telephone was made by Philip Reis, a 

 teacher in a school at Friedrichsdorf, near Homburg. 

 On October 26, 1861, Reis showed his instrument, which 

 he termed a "telephone," to the Physical Society of 

 Frankfort-on-the-Main ; and on that occasion he suc- 



1 Phil. Ttans., vol. 167, Pt. i. 



^ Since this has been in type TDr. Haughton has read another paper 

 before the Royal Society, in which he concludes, from purely geological 

 evidence, that ''the hypothesis of a shifting pole (even if permitted by 

 mechanical considerations) is inadmissible to account for changes in 

 geological climates." Therefore whether he agrees or not in the justice of 

 my mechanical criticism, he seems to be of opinion that the wabbling of the 

 earth will not give geologists much light as to the duration of geological 

 time. 



ceeded in electrically transmitting various melodies, 

 which were distinctly heard throughout the room. In 

 the paper he read before this Physical Society, pub- 

 lished in the annual report of the Society for i86r, 

 Reis states : — " Melodies were sung, not loudly, into the 

 transmitting apparatus placed in a hospital some 300 feet 

 away from the audience, care being taken that no 

 sound could be heard, by direct transmission, or by con- 

 duction along the wires. The sounds of various musical 

 instruments were clearly reproduced, as the clarionet, 

 horn, organ- pipe, and even harmonium and pianoforte 



Fig. I. — This and Fig. 2 show the usual but imperfect form of Reis's tele- 

 phone. Fig. I is the transmitting apparatus, t represents the mouth- 

 piece, tri the membrane closing the upper portion of the box K, a portion 

 of which is cut away to show the movable lever, a b c, resting by a 

 projecting point b, on the platinum disc o, fixed to the centre of the 

 membrane and connected with the binding screw 2. The arm ab c\i 

 metallicly connected with the binding screw 2. The key t closes the 

 circuit when the instrument is in use, and the electro-magnet ee is for 

 the purposejof receiving communications. 



when the transmitter was placed on their sound-boards, 

 provided the tones were within the compass of f to f". 

 Articulation was not reproduced equally well. Conso- 

 nants, however, were in general pretty clearly heard, but 

 not the vowels." In this report, which is entitled 

 " Telephony by Means of Electric Currents," Reis shows 

 how he was led to the construction of his instrument by 

 a study of the mechanism of the organ of hearing, and of 

 the manner whereby sounds are perceived by the human 

 ear, and he gives a series of diagrams representing the 

 resultant curves that would be produced by the combina- 



FlG. 2 IS the receiving apparatus, b and d are resonant boxes, g is the coil 

 through whicn the current pa-:ses magnetising t.he iron wire d, -x and 4 

 are binding screws to which the line and return wire are attached the 

 circuit being closed by the key i. 



tion of various concords and discords. Thus, he was led 

 to perceive that " if it were possible to create, in any 

 manner, a mode of vibration whose curve resembles that 

 of any tone or chord, then a sensation would be produced 

 similar to that given by the tone br chord itself." This 

 principle, he affirms, guided him onwards. 



The first instrument he made was constructed of very 

 homely materials. The bung of a beet-barrel was pierced 

 through with a conical hole, the smaller end was then 

 covered by a membrane, the skin of a German sausage 

 being used for this purpose ; to this was fixed, with a drop 

 of sealing-wax, a little strip of platinum joined up to one 



