August 9, 1883] 



NA TURE 



359 



these turbines, which are perforated, and the syrup passes 

 through the holes, while the sugar remains behind. This sugar 

 is cooled, and is called sugar No. I. The syrup is boiled over 

 again so as to obtain a second sugar called No. 2, and by a 

 similar process a sugar No. 3 is obtained. The time of crystal- 

 lisation, however, increases greatly, and for syrup No. 3 it is as 

 much as six months. The final resi lue is molasses, which con- 

 tains a large proportion of sugar that cannot be reduced by 

 boiling. It is sold to make alcohol, or subjected to osmosis, by 

 which the salts contained are drawn off and replaced by water ; 

 the sugar is then revivified and rendered capable of being crys- 

 talised. The paper concluded by giving careful analyses of the 

 juice and of the products in all the stages of manufacture. 



The next paper read was "On the Application of Electricity to 



the Working of Coal-Mines," by Mr. A. C. Bagot. The writer 



lied a system of electric signals replacing the old system of 



Ming from the bottom to the top of the shaft by a gong 



worked by means of a wire. Galvanised iron telegraph wire 



was found to form the best communication, and the most suitable 



batteries to be I2-cell Leclanche. The system used for signalling 



in underground haulage planes, which are frequently the scene 



of accidents, was also described. Electricity had also been 



ied to signal the indications of an anemometer placed in the 



return air-way up to the engine-room at the surface. By an 



arrangement of clockwork and revolving tape, the engineer 



ins an automatic and continuous record of the speed of the 



main air current at any part of the mine. Lastly the telephone 



might be applied with advantage for hearing the action of the 



pump-valves in the pumping shaft, without having to send the 



sinkers down. 



Electricity may, however, be brought to bear for other purposes 

 in mines, such as illumination and transmission of power. For 

 lighting the pit bank, powerful arc lamps are found very service- 

 able, and the ordinary staff of a colliery, after a week's instruc- 

 tion, is capable of maintaining the appliances in operation. 

 Alternating high-tension machines are very unadvisable on 

 account of the likelihood of accident, and the Edison low-tension 

 machine is said to be the best thai can be used. At Risca Col- 

 liery a cable is taken down the pit from a dynamo at the surface, 

 and is connectel with a series of Crompton incandescent lamps 

 at the bottom. These give an excellent light, and greatly facili- 

 tate the work of the men about the bottom of the shaft. But 

 Mr. Bagot's opinion is strongly against the use of electric lamps 

 in the working stalls and faces; partly because such lamps do 

 nit, like safety-lamps, indicate the approach of gas, partly 

 because the line-wires may easily be broken, and partly because 

 the hewer require; to be constantly shifting his light. With regard 

 to the transmission of power by an electric tramway, as now in 

 use at Zankerode, the writer holds that small locomotives worked 

 by steam or compressed air are at present far more economical ; 

 so that the question of electric haulage need not in his opinion 

 be considered at present. 



These latter opinions did not pass without challenge. M. 

 Tresca, who was present, pointed out that there was another 

 form of electric transmission, viz. by a fixed cable with a dynamo 

 at each end. Where work had to be done at some special part 

 of a colliery, especially on an emergency, he believed that this 

 would be found a handy and economical system. At the mines 

 of La Perroniere power was thus conveyed to a distance of 500 

 metres, and with a useful effect of about 30 per cent. This, in 

 spite of over-bold statements to the contrary, was about the 

 utmost which at present could be obtained in practice. The 

 various sources of loss in such transmission were enumerated as 

 follows : — First getting up the speed from that of the motor 

 engine to that of the generator ; secondly, loss within the gene- 

 rator itself; thirdly, loss in transmission along the cable ; fourthly, 

 loss within the receiver ; fifthly, loss in slowing down the speed 

 of the receiver to that of the main shaft. These defects were 

 all now fully recognised, and might gradually, he hoped, be 

 overcome. With regard to the amount of power which could 

 thus be transmitted, the well-known experiments of M. Deprez 

 showed 5 to 6 h.p. But within the last week he had succeeded 

 in transmitting 31 h.p. from a Gramme machine to a great dis- 

 tance. The facility of installation was a great advantage in this 

 system of transmission. It was far superior to that by an elec- 

 tric locomotive, as to which at present he had little to say ; but 

 on the whole he was more firm than ever in the view that a 

 negative conclusion with regard to the electrical transmission of 

 power was at any rate premature. 



The next paper was by Mr. Webb, of Crewe, upon "Com- 

 pound Locomotive Engines." It described the system devised 



by him, and now carried out in several engines running upon the 

 London and North-Western Railway. 



The last paper read at Liege was on the St. Gothard Railway, 

 by Herr Wendelstein of Lucerne. This paper gave an interesting 

 description of the works of the railway, and of the Brandt 

 h)draulic drill, which was used with great success for one of the 

 spiral tunnels. It then passed on to the question of ventilation, 

 which was very fully gone into. Tables were given of the tem- 

 perature in the great tunnel during and after construction, to- 

 gether with an account of the observations made on the 

 ventilation both of that tunnel and of the spiral tunnels. The 

 subject is as interesting from a scientific as it is important from a 

 practical point of view, the result being that artificial measures 

 of ventilation, the necessity for which was fully discussed, are 

 found to be wholly needless. We regret that space does not 

 allow us to reproduce this part of the paper. 



During a subsequent visit of the'Institution to Antwerp, a 

 paper was read by M. Royers, describing the great harbour 

 works which are now being constructed at that city, especially 

 the long quay wall which is being built far out in the river by a 

 special system of floating cofferdam designed by Mr. Hersent. 

 In addition to these papers a large number of notices of the 

 works to be visited, &c, had been prepared and were 

 distributed at the meeting. We understand that copies of any 

 of these, or of the papers above mentioned, may be obtained on 

 application to the Secretary, 10, Victoria Chambers, West- 

 minster, S.W. 



GEOGRAPHICAL NOTES 



In the Transactions of the Berlin Geographical Society (May- 

 June) is an intere ting paper by Herr Arthur Krause on South- 

 eastern Alaska, or that strip of coast stretching from Mount 

 Elias to Fort Simpson, comprehending about 120 miles breadth 

 of continent, and the numerous islands lying alongside of it. 

 Ilerr A. Krause passed the winter of 1882 with his brother at a 

 factory to the north of the Lynn Canal, making short tours the 

 following spring into the interior, as far as the Yukon district, 

 and Ilerr Krause's paper is the result of his observations. The 

 lower course of the Yukon River, as far as Fort Yukon, has 

 been traced and astronomically observed by Raymond in his 

 " Reconnaissance of the Yukon River, 1871." Its upper course 

 and sources, on the other hand, have only seldom been visited 

 by people of the Hudson's Bay Company and by gold seekers. 

 The most important head stream is the Polly River, which springs 

 from France's Lake on the west of the Rocky Mountains. From 

 the south the Polly receives a powerful current, figuring in 

 certain maps as the Lewis River. A northern offshoot 

 of the Lynn channel cuts so deeply into the interior that 

 in two short days' marches you can pass thence to the Yukon 

 river. To the north of the Lynn Channel is the varied district 

 of Chileat, forming the watershed between the coast and the 

 Yukon river, and parting two distinct zones of flora and fauna. 

 The Chileat district, like the whole of the west coast, is moun- 

 tainous, and its peaks condensing the vapour driven by western 

 winds from the warmer region of the sea, the whole western 

 tract is distinguished by its violent falls of rain in summer and 

 snow in winter, as also by its abundance of glaciers. Glacier 

 Bay, to the west of the entrance of the Lynn Channel, is quite 

 filled with ice in consequence of vast glaciers falling into it. All 

 the valleys, too, along the coast abound in glaciers. As soon, 

 however, as the watershed and the slope towards Yukon river 

 are reached, the glaciers disappear. With this change also 

 appears a corresponding change in vegetable and animal forms. 

 The low banks and islands along the coast are covered with pop- 

 lars, alders, willows, and thickets. Higher up on the slopes 

 you meet a thick belt of pine. A few green trees of diminutive 

 size, birch, maple, and mountain ash, may be observed, but these 

 are mostly interwoven in the enormous thick underwoods of the 

 pine forests. In some lower-lying spots an almost tropical 

 luxuriance of vegetation surprises the traveller. On the inland 

 side of the watershed the whole physiognomy of vegetation is 

 in striking contrast with that on the sea side — is barer, drier, 

 and lighter. Instructive particulars are also given by Herr 

 Krause regarding the fur and fishing trades of this region. 



In the Bulletin of the Italian Geographical Society for 

 July is a paper giving a historic survey of the Harar dis- 

 trict, Somaliland, by the Rev. P. Taurin Cahague. Great 

 interest attaches to this place since Frederick Muller has 

 shown that it forms a distinct ethnologic enclave allied to 



