124 



SCIENCE 



[Vol. IV., No. 79. 



necessary in the wires by sixty per cent; but this 

 figure is probably too high. If the electromotive 

 force of the dynamo is too high for the lamps, a third 

 wire between the two principal conductors may be 

 used, and the lamps inserted between this and the 

 two principal conductors. 



Fig. 2. 



Fig. 2 represents an arrangement invented by Mr. 

 J. S. Beesman: it is composed of two dynamos, con- 

 nected as shown, the two circuits of the dynamos 

 being joined crosswise by the lamps. It will be seen 

 that this arrangement permits each lamp to have the 

 same difference of potential between its extremities, 

 because, as each lamp is nearer one of the dynamos, it 

 is the more distant from the other. If the lines are 

 considered as rails, or other conductors on an electric 

 railway, the speed will be the same at all points of 

 the line ; for the difference of potentials between the 

 conductors will be constant: consequently, if several 

 trains of the same weight run over the same line, 

 they will not strain to go by each other. 



— Among recent German patents is one issued 

 to D. French St. George of London, for a novel 

 form of phonograph. The cut shows a round photo- 

 graphic plate a, upon which a ray of light falls 

 through the opening at e. A slide over this opening 

 is connected with the vibrating plate in the mouth- 



piece g in such a way, that, with the vibrations of the 

 plate, the size of the opening is varied. The result 

 is, that on the photographic disk, which is kept in 



rotation at a constant rate, there is produced, after 

 development, a dark circle of varying width. In order 

 to reproduce the tones of the voice, a ray of light is 

 sent through this photographic image upon a selenium 

 transmitter of the form invented by A. Graham Bell, 

 and used in his radiophone. 



— The Berlin African association despatched an 

 expedition to the Kongo during July, of which Lieut. 

 Schulz is to be the leader. News has been received of 

 the two travellers for this association, — Dr. Richard 

 Bohm, and the engineer, P. Reichard, — of the date 

 of last August. They had crossed Lake Tanganyika 

 with the Belgian agent at Karema, Lieut. Storms, to 

 Qua Mpara, and started across unexplored country 

 for Lake Moeso. The Illustrirte zeitung states that 

 Dr. Bohm is to succeed Lieut. Storms in command at 

 Karema. The International African association has 

 founded thirty-two stations in addition to Leopold- 

 ville. Ten of these are on the Niadi-Kwilee, twenty 

 on the Congo, and two on the coast. During his last 

 journey, Stanley acquired a considerable length of 

 the river-bank. By means of the steamers and the 

 new roads round the rapids, the journey to Stanley 

 Pool can now be made in fourteen days. Col. Win- 

 ton has taken the command between Vivi and Stan- 

 ley Pool. 



— M. J. B. Morot, lately deceased, left to the 

 Societe de geographie a sum of two thousand francs, 

 the interest of which is to form an annual prize for 

 the French navigator who shall approach nearest 

 to the north pole during the year ; or, in default of a 

 suitable receiver, the prize may, at the discretion of 

 the society, accumulate for two years. In the absence 

 of an arctic navigator, it may be awarded to the dis- 

 coverer of an unknown island or country. 



— Capt. Sorensen has determined that the north- 

 ern point of Europe is not Cape North, as usually 

 assumed, but a promontory called Knivskjoerodde, 

 about ten minutes of longitude west from Cape 

 North, and reaching nearly a thousand metres in a 

 northerly direction beyond the extremity of Cape 

 North. 



— Three important memoirs on the geology and 

 geography of eastern Europe have lately appeared. 

 The first, by Dokuchaeff, treats of the distribution 

 of the black loam (chernoi zemlia) of Russia, famed 

 for its fertility. Another, by Paul Veniukoff, con- 

 siders the distribution of the Devonian rocks of Rus- 

 sia. The third, by Vitikin, discusses the formation 

 of the valleys of central Russia. These, according 

 to the author, are due to a gradual elevation of the 

 land, which left the edges of a shallow sea trans- 

 formed into plains, across which brooks made their 

 way, cutting out ravines and channels, growing in 

 importance and volume as the area of land enlarged, 

 and finally becoming rivers. There was no lake- 

 period, as in the Baltic region. With few exceptions, 

 the lakes of central Russia are ancient river-beds, 

 cut off by changes in the course of the stream. Behr's 

 law is exemplified in the valleys, of the principal 

 streams, which, like the Volga, Viatka, and others, 

 have a general parallelism with the meridian. 



