June 20, 1878] 



NATURE 



207 



was successful also so far as demonstratinj the possibility of 

 motion ; but the apparatus was so imperfect that the balloon 

 moved very slowly indeed, and another apparatus has to be made 

 by the French experimentor. Instead of using common 

 lighting gas, Prof. Ritchel resorted to pure hydrogen. His 

 balloon had only 3,000 cubic feet measurement whilst Capt. 

 A rdisson's wanted about ll,oco. Capt. Ardifson's motor was 

 composed of two very imperfect fans worked with the hand. 

 Prof. Ritchel used a screw propeller moved with both feet, so 

 that he had his hands free for working a horizontal fan, for 

 ascending and descending at pleasure. Instead of constructing 

 a spherical balloon. Prof. Ritchel had prepared a cylindrical one 

 similar to the balloon Delamare tried fifteen years ago without 

 succes, in the open air. It is stated that Prof. Ritchel's success 

 was very great, and the experiment will be tried again in Phila- 

 delphia, and probably soon in Pari«. These experiments, M. 

 de Fonvielle thinks, disprove the scheme advocated by the head 

 of the French balloon service. Col. Laussedat, who, in a paper 

 recently referred to in Nature, suggested that the motive power 

 should be applied to the balloon instead of being annexed to 

 the car. 



A VALUABLE sketch of the development of the natural sciences 

 in Holland, has lately appeared in Leydea from the pen of Dr. 

 B. van Haan. 



The late investigations of Count Wurnbrand, en the loess 

 formations of the Danube in Moravia, lead him to the opinion 

 that these deposits are entirely of an alluvial origin, and not due 

 to diluvial disturbance^. A large variety of fragments of char- 

 coal, carved bits of bone and horn, flints, &c., accompanying 

 the collections of animal remains found in the e strata, point 

 with great certainty to the existence of mankind at the time of 

 their formation. 



An interesting archa:ological discovery is chronicled by the 

 Berne papers. A forest in the neighbourhood is found to grow 

 above a biuried Roman town. Numerous edifices have been 

 laid bare, and the various remains which have been unearthed 

 show it to have teen inhabited by the officers of the Roman 

 forces, who occupied the strong defensive positions on the river 

 Aar. 



Among the more important- scientific novelties in the German 

 book trade during the past month, we notice the following 

 works : — " Die Dolomit-Riffe von Sudtirol und Venetien," iste 

 Lief., Dr. E. von Mogsisovics (Vienna) ; " Die Reptilien und 

 Fische der bohmischen Kreideformation," Prof. A. Frie 

 (Prague) ; "Die Erdrinde und ihre Biliiung," J. Lippert (Prague) ; 

 " Vortrage iiber Geologic," F. Henrich (Wiesbaden); "Die 

 Geologic und ihre' Anwendung auf die Kenntniss der Boden- 

 beschaifenheit der oesterr. -ungar. Monarchie," F. von Hauer 

 (Vienna); " Exkursionsflora fiir Mittel- und Norddeutschland," 

 Exknrsionsflora fiir Suddeutschland," Dr. M. Seubert (Stutt- 

 gart) ; " Taschenbuch der deutschen und schweizer Flora," E. 

 Hallier (Leipzig) ; "Flora von Deutschland," Prof. A. Garcke 

 (Berlin) ; " Die Schule der Physik," J. Miiller (Brunswick) ; 

 "Grundziige der Elektricitatslehre," W. von Beetz (Stuttgart); 

 "Lehrbuch der Physik," F. J. Pisko (Briinn); "Sonne und 

 Monde als Bildner der Erdschale," J. H. Schmick (Leipzig) ; 

 " Ueber Meerstromungen," E. Witte (Pless) ; " Anleitung zum 

 Experimentiren bei Vorlesungen iiber anorganische C hemic," 

 Prof. K. Heumann, III. (Brunswick) ; " Anleitung z;ir quanti- 

 tativen chemischen Analyse," Prof. C. R. Freseni;i«, II. 2 

 (Brunswick). 



\ye have upon oiu: table the following books: — "Outlines 

 ■, of Physiology," by Dr. McKendrick (Maclehose, Glasgow); 

 "Choice and Chance," third edition, by W. A. Whitworth, 

 M.A. (Deighton, Bell, and Co., Cambridge) ; "A Library Map 

 ;- of London and its Suburbs," by J. B. Jordan (Stanford); "A 



Geological Map of England," by Prof. Ramsay (Stanford)' 

 "A Geological Map of Ireland," by Prof. E, Hull (Stanford) ; 

 "Grundziige der Electricitatslehre," by Dr. W. von Bertz 

 (Stuttgart) ; "A Candid Examination of Theism," by Physicus 

 (Triibner and Co.); "A School Flora," by Dr. Marshall Watts 

 (Warne and Co.). 



The additions to the Zoological Society's Gardens during the 

 past week include a Black-faced Spider Monkey (Ateles ater) 

 from East Peru, an Ocelot {Felis pardalis), a West Indian Rail 

 {Aremuies cayennensis), a Black Tortoise {Testudo carbonaria), 

 a Common Boa {Boa constrictor) from South America, presented 

 by Capt. J. Moir; a Himalayan Bear (C/rsus tibetanus), aii 

 Indian Crow (Corvus splendcns) from India, presented by Capt. 

 J. S. Murray; a Rufous Rat Kangaroo {Hypsiprymnus ru^es- 

 cens) from New South Wales, presented by Mr. Thos. Wick- 

 enden ; Six Herring Gulls {Lams argentatus) European, pre- 

 sented by Mr. Arthur Clarke ; two Black-crested Cardinals- 

 {Gubernatiix cristaielld) from South America, aii American 

 Thrush (Turdus migratorius) from North America, presented 

 by Mrs. Arabin ; a Black Saki {Pithecia satanas) from the 

 Lower Amazons, a Spotted Cavy {Ccelogenys paca), a White 

 Ibis [Ibis alba) from South America, purchased ; a Chimpanzee 

 ( Troglodytes niger) from West Africa, deposited ; a Reeves's 

 Muntjac {Cerz/ulus reez'esii) born, six Upland Geese (Bemicla 

 magillanica), a Brazilian Teal {Querquednla brasiliensis) bred in 

 the Gardens. 



THE MICROPHONE^ 



A LATE member of the pre.-ent ministry, at a dinner given 

 ■^ by the institution whose hospitality we experience in this 

 hall, implied, on the authority of one of the leading members of 

 the engineering profession, that invention, like cocktails and 

 Colorado beetles, had taken root in America and had deserted 

 old England. It is therefore to me, as I am sure it is to you» 

 a great gratification to have brought before us an invention 

 which is the offspring of British soiL During the last few months 

 the science of acoustics has made marvellous and rapid strides. 

 First of all we had the telephone, which enabled us to transmit 

 human speech to distances far beyond the reach of the ear and 

 the eye. Then we had the phonograph, which enabled us to- 

 reproduce sounds uttered at any place and at any time ; and now 

 we have that still more wonderful instrument, which not only 

 enables us to hear sounds that would otherwise be inaudible, but 

 also enables us to magnify sounds that are audible ; in other 

 words, the instrument which I shall have the pleasure of bring- 

 '\a.'y before you to-night, is one that acts towards the ear in the 

 same capacity as the microscope acts towards the eye. 



I may point out, in the first instance, that the telephone and 

 the phonograph depend essentially upon the fact — and a great 

 fact it is — thit the mere vibration of a diaphragm can reproduce 

 all the tones of the human voice. In the telephone the voice 

 is also made to vibrate a diaphragm, which, by completing an 

 electric circuit, or by varying a magnetic field, or by altering the 

 resistance or electromotive force of the circuit, produces effects 

 at a distance which result in the reproduction of the motion of 

 the diaphragm. Bat in this new instrument diaphragms are cast 

 aside, and we have the direct conversion of sonorous vibrations, 

 or sound waves, into forms of electrical action. 



Now, if it had been the habit or the custom of this Society to 

 give to the papers and discussions delivered here sensational 

 titles, I should have been inclined to call the few remarks I am 

 going to make to-night, "A Philosopher Unearthed." Prof. 

 Hughes is well known to us all ; he has been more or less asso- 

 ciated with this Society since its first inception. Whenever he 

 is in London he is amongst us. His instrument is well known 

 to us as one of the most exquisite pieces of mechanism ever in- 

 vented ; and his works, though few, are known because they are 

 sound. ITie chief characteristic of this philosopher whom I 

 have succeeded in unearthing, is his extreme modesty. If he 

 had been left to himself, I do not think we should ever have had 

 the microphone here ; but, by a lucky chance, he admitted me 

 into his secret, and following, as I have done, all his steps, I am 



I A lecture given before the Society of Telegraph Engineers, on May 

 23, by W. H. Preece, V.ce-President Soc. T.E., Memb. Inst. CE., &c., &ci 



