566 



NATURE 



[April 14, 1898 



should take place at the beginning of June. In addition to the 

 Paris, Strasburg, Berlin, and Petersburg stations, two new 

 stations will be established in Vienna at the expense of the 

 Minister of War, and in Brussels. The expenses will be sup- 

 ported by the Belgian-Deutsch Society of Astronomy, which 

 sent to Strasburg, as their representative, M. Fievre, one of their 

 secretaries. The next meeting will take place in Paris in 1900, 

 on the occasion of the forthcoming exposition. Among the 

 members present at the recent meeting were the director of the 

 Russian Meteorological Service ; Commander Kovanko, director 

 of the Russian Aeronautical Service ; Herr Assmann and Dr. 

 Berson, of the Berlin Meteorological Institute ; M. Cailletet, 

 member of the French Academy of Sciences ; M. Teisserend 

 de Bort ; Mr. Rotch, director of the Blue Hill Observatory in 

 Pennsylvania ; M. Besan9on ; and Prof. Heim, the Swiss geo- 

 logist, professor in the Zurich Polytechnicum. 



We regret to see that Mr. James I'Anson, an occasional con- 

 tributor to our correspondence columns, died a few days ago. 

 From the Engineer we learn that Mr. I'Anson was born at 

 Gateshead in 1845, ^""i came of an old North-country family. 

 Soon after leaving school he commenced his apprenticeship as a 

 mechanical engineer, and in 1866 he entered the engineering 

 works of the late firm of Charles FAnson and Co., becoming 

 subsequently a partner. Some time after he became managing 

 partner, a position which he held until his retirement in 1885. 

 Mr. I'Anson was for many years a Fellow of the Geological 

 Society, and he also sat upon the Council of the Mineralogical 

 Society of Great Britain and Ireland. He was a member of the 

 Iron and Steel Institute and of the North of England Institute 

 of Mining and Mechanical Engineers, to whose proceedings he 

 contributed papers, as also to those of the Cleveland Institute of 

 Engineers, the Mineralogical Society, and the British Archae- 

 ological Association. 



Among the problems interesting to the physicist and mathe- 

 matician which are discussed at the meetings of the Institution 

 of Naval Architects, few open up such a wide field of inquiry 

 as those which form the subject of Prof. H. S. Hele-Shaw's 

 paper, entitled "Investigation of the nature of surface-resist- 

 ance of water, and of stream-line motion under certain experi- 

 mental conditions," read before the recent meeting of the In- 

 stitution. In a previous paper, read last July, the author 

 showed how the flow of water in two dimensions past obstacles 

 of various cylindrical and prismatic forms could be investigated 

 experimentally by the use of water containing a quantity of air 

 flowing between two parallel plates of glass, the air rendering 

 the water turbulent where the motion was most rapid. The 

 photographs, which Prof. Hele-Shaw reproduces, show in every 

 case a clear line round the boundary of the solid, indicating a 

 thin film in which shearing motion takes place past the surface, 

 while outside this comparatively calm region streaks of air 

 are noticeable. The figures, moreover, show the presence of 

 regions of dead water behind obstacles with blunt edges, fully 

 confirming the view that to minimise resistance a solid must 

 be made to taper at its stern end rather than at its bow end. 

 In the present paper diagrams are given showing the vari- 

 ations in thickness of the entrained film according to the 

 smoothness or roughness of the surface of the solid, the addition 

 of soap to the water, and other circumstances. A second field 

 of experiment has been developed by the use of thin films of 

 water flowing between parallel plates, in which the stream-lines 

 are shown by the introduction of coloured bands. Unless the 

 film be very thin (about 05 mm.), the lines of colour become 

 blurred, especially after flowing round an obstacle. The most 

 remarkable result is the coincidence between the stream-lines in 

 these experiments, where we are probably dealing with a case of 

 laminated motion of a viscous liquid largely aff"ected by the 



NO. 1485, VOL. 57] 



bounding plates of glass, and the corresponding stream-lines 

 calculated mathematically for the irrotational motion of a perfect 

 liquid in two dimensions. It has been one of the great objections 

 to the mathematical theory of fluid motion that the conditions 

 imposed by the mathematician diff'er considerabfy from those 

 occurring in practice. Prof. Hele-Shaw's investigations, how- 

 ever, bid fair to bring hydrodynamics within the range of 

 experimental sciences, besides fulfilling the object for which they 

 were primarily undertaken — that of teaching naval architects 

 how to minimise the surface-resistance on ships. 



At the meeting of the Institution of Civil Engineers on April 

 5, Mr. A. H. Preece gave an account of the present state of 

 electricity supply in London. There are now in London eleven 

 important companies and five vestries supplying electricity, and 

 three other companies and three vestries are taking steps to start 

 works. Five companies and three vestries supply the alternating 

 current, and the remainder use direct-current systems. The 

 direct-current systems are divisible into two classes — the high- 

 pressure and the low-pressure. In the former, rotary trans- 

 formers are used to reduce the high pressure to a low pressure, 

 while the latter produces and distributes electricity at the same 

 pressure at which it is supplied to consumers. The direct-current 

 systems are applicable to compact areas, and, with the use of 

 high pressure, to scattered or isolated compact areas. The 

 chief advantages of the direct-current system are the possibility 

 of using storage-batteries, which can not be employed with the 

 alternating-current systems, greater efficiency in distribution, and 

 greater adaptability to motive power. The favourite methods 

 of distributing electricity are to transmit current at a high 

 pressure in heavily-insulated cables in iron pipes, and current at 

 a low pressure in insulated cable in stoneware conduits, or in 

 cables heavily armoured and laid direct in the ground. Rubber 

 is now little used, paper and jute, impregnated with insulating 

 compounds, having been extensively adopted. The electric 

 supply industry is rapidly growing, and no less than 40,000 h.p. 

 is now being installed in London in order to meet the demand 

 for electricity in the immediate future. 



The Times correspondent at Cairo makes the important 

 announcement that M. Loret has discovered and opened at 

 Thebes the tomb of Amenophis II , a king of the XVIII. 

 dynasty, who reigned some 1 500 years B. c. The tomb contains 

 the mummies of Amenophis and of seven other kings, besides 

 two mummies bearing no name, and four bodies which, though 

 they have not been embalmed, are all in a complete state of 

 preservation, with the features perfect. The hair upon each of 

 these bodies is luxuriant, and the features are said to resemble 

 to a marked degree those of the fellaheen of the present day. 

 M. Loret's find is amongst the most interesting ever made in 

 Egypt. 



The Central Physical Observatory of St. Petersburg has 

 published an interesting pamphlet showing, for the whole of the 

 Russian Empire, the absolute maximum and minimum tem- 

 peratures at about 230 stations, accompanied by three maps, 

 illustrating the above elements, and the ranges of temperature. 

 The observations at some of the stations extend over a long 

 series of years, e.g. St. Petersburg, 142 years ; Moscow, 90 

 years ; and Archangel, 80 years. The most remarkable tem- 

 peratures and ranges are recorded in the Province of Yakutsk, 

 in Siberia :— Verkoiansk, - 90° F. with a range of 182° 7 ; 

 Markinskoe, - 8s°-o, range i8s°-2; Yakutsk, - 84°-!, range 

 1 85° 7. All these extreme minima occurred in the month of 

 February, and the stations being a considerable distance apart, 

 testify to their accuracy and to the great rigour of the winter of 

 that locality. The work has been compiled by Mr. A. Varnek ; 

 but the text being in Russian only, detracts somewhat from its 

 general usefulness. 



