July 17, 1890] 



NATURE 



287 



agreement with what has been stated above, an expansion of 

 three or four times usually sufficed to convert the ordinary water 

 surface into one upon which superficial viscosity was tending to 

 disappear. 



I propose to make determinations of the actual tension of sur- 

 faces contaminated to various degrees ; but in the meantime it 

 is evident that the higher degrees of purity do not imply much 

 change of tension. In the last experiment, upon a tolerably 

 pure surface, if we cause the needle to oscillate rapidly backwards 

 and forwards through a somewhat large angle, we can clear 

 away the contamination from a certain area. This contamina- 

 tion will, of course, tend to return, but observation of motes 

 shows that the process is a rather slow one. 



The smallness of the forces at work must be the explanation 

 of the failure to clean the surface in Plateau's apparatus by mere 

 expansion. For this experiment the end wall was removed from 

 the tail-piece (Fig. 3), and a large flexible hoop substituted. 

 By this means, it was hoped that when the whole was placed in 

 the bath it would be possible, by mere expansion of the hoop, 

 to obtain a clean surface in the well. The event proved, how- 

 ever, that the purification did not proceed readily beyond the 

 earlier stages, unless the passage of the contamination through 

 the long channel of the tail-piece was facilitated by wind.] 



UTILIZATION OF NIAGARA FALLS. 

 A SYNDICATE in the United States have acquired a con- 

 -^*- siderable area of land on the American side of the Niagara 

 River, at some distance above the great Falls. They propose to 

 use it for mill sites, and to supply the mills with power by utiliz- 

 ing a small fraction of the water-power which is available on 

 the Falls. The actual fall of level at Niagara is about 200 feet. 

 Suppose that about 4 per cent, of the water going over the Falls 

 is taken, and an effective fall of 140 feet, irrespective of losses 

 in the tail race, obtained, there might be utilized i20,cx3o horse- 

 power. It is proposed to take the water by a short lateral canal, 

 fo allow it to descend vertically in shafts in which turbines will 

 be placed, and then to discharge it by a tunnel tail race passing 

 beneath the present town of Niagara, at a point below the 

 Falls. It is part of the plan to transmit a portion of the power 

 to the important manufacturing town of Buffalo, eighteen miles 

 distant. 



The project involves problems of very great complexity. The 

 hydraulic motors will be of a size not hitherto constructed, and 

 the governing conditions are different from those commonly met 

 with where water power is utilized on streams of variable and 

 limited flow. Then in the distribution of the power further 

 problems arise. Power can be distributed to great distances by 

 Hirn's system of wire ropes, as at Schaffhausen ; by water or air 

 under pressure, as in the compressed air systems of Paris and 

 Birmingham and the Hydraulic Power Company's system in 

 London. In Switzerland and America progress has been made 

 in distributing large power to great distances electrically. The 

 choice amongst such methods of those which are most economical 

 and most likely to suit the wants of mill-owners, requires very 

 careful consideration. 



Hence the Cataract Company have resolved to invite from 

 certain selected engineers and engineering firms, plans for the 

 utilization at Niagara of 120,000 horsepower, and to submit 

 the plans for an authoritative opinion to the judgment of a 

 Scientific International Commission. The Commission will 

 consist of Sir William Thomson, F.R.S., as President; Prof. 

 Mascart, Member of the Institut, and Director of the Bureau 

 Central Meteorologique, Paris ; Colonel Theodore Turrettini, 

 who was director of the works of the Saint Gothard Tunnel, 

 and is dhector of the works for the utilization of the motive 

 power of the Rhone at Geneva ; and, lastly. Dr. Coleman 

 Sellers, formerly of the • firm Of Messrs. Sellers and Co., of 

 Philadelphia, atid iTow Professor of Engineering at the Stevens 

 Institute, Hoboken," and at the Franklin Institute of Pennsyl- 

 vania. Prof. W. C. Unwin, F.R.S., is the Secretary to the 

 Commission. 



SOCIETIES AND ACADEMIES. 

 London. 

 Linnean Society, June 19.— Prof. Charles Stewart, Presi- 

 dent, in the chair.— Mr. W. H. Beeby exhibited a specimen of 

 Rumex propinquus new to Britain, and procured in Shetland. 

 NO. 108 1, VOL. 42] 



— Mr. Thomas Christy exhibited and made remarks upon a 

 specimen of Callistemon rigidum. — Mr. E. M. Holmes exhibited 

 some marine Algae new to Britain, including Ascocyclus reptans, 

 Halothrix lumbricalis, Harveydla mirabilis, Sorocarpus 

 uvcefoi-mis, and Vaiicheria liiorea ; also specimens of Rhody- 

 menia palmata with antheridia, and Pundaria teniiissima in 

 fructification, the last two not having been previously recorded 

 to occur in this state in Great Britain.— The following papers 

 were then read : — Observations on the protection of buds in the 

 tropics, by M. C. Potter.— On the distribution of the South 

 American Bell-birds belonging to the genus Chasviorhynchus, by 

 J. E. Harting.— On the vertical distribution of plants in the 

 Caucasus, by Dr. Gustav Radde.— Notes on the Forficulidce, 

 with descriptions of new genera and species, by W. F. Kirby. — 

 This meeting terminated the Session of 1889-90. 



Entomological Society, July 2.— Prof. J. O. Westwood, 

 Hon. Life- President, in the chair. — Lord Walsingham ex- 

 hibited some rare Micro-Lepidoptera collected by himself 

 at Cannes, including Eudemis helichrysana, Conchylis rubri- 

 cana, Milliere ; a new Depressaria from Opoponax cheironium, 

 which is about to be described by M. A. Constant, and 

 Bucculatrix helichrysella ; and also a volume of drawings 

 of larvre of the genus Eupitheda, by Mr. Buckler, which 

 formerly belonged to the late Rev. H. Harpur Crewe.— Mr. 

 McLachlan exhibited larva; and cocoons of Mecyna depj ivalis. 

 Walk., sent by Mr. W. W. Smith, of Ashburton, New Zealand ; 

 the species feeds commonly on Genista capensis, an introduced 

 plant.— Mr. S. Stevens, in speaking of a tour which he had 

 lately made in Devonshire, remarked on the extreme scarcity of 

 insects on the coast of that county as compared with the coasts 

 of Kent and Sussex ; there were very few larvas, and the 

 vegetation was very luxuriant and very little eaten : he thought 

 it possible that the reason of the scarcity was the heavy rainfall 

 of South Devon, which washed off and destroyed the young 

 larvoe. Mr. Barrett said that his experience had been the same, 

 and that he put it down to the violence of the winds which beat 

 the insects from the trees. Mr. Blandford remarked that he 

 had found Coleoptera abundant on the Braunton Burrows, near 

 Barnstaple, but very scarce in other localities. Mr. Mason and 

 others took part in the discussion which followed. — Prof. 

 Westwood read a paper on a species of Aphis affecting the 

 bread-fruit tree, which he had named Siphonophora artocarpi : 

 at the conclusion of his paper he alluded to the use of Paris- 

 green as a destructive agent for insects. Mr. Blandford then 

 made some remarks as to the use of London-purple (another 

 arsenic compound) as an insecticide in the place of Paris-green ; 

 he stated that the compound was a waste product, and one-tenth 

 the cost of Paris-green, and further that it was more soluble and 

 more easily applied ; he was also of opinion that arsenic 

 compounds do not greatly affect sucking insects, such as 

 Aphides, the ordinary kerosene preparations being more suitable 

 for their destruction. Several Fellows took part in the discussion 

 that followed. 



Edinburgh. 



Royal Society, June 16.— The Hon. Lord M'Laren, V.P., 

 in the chair. — A list of West Australian birds, showing their 

 geographical distribution throughout Australia, by Mr. A. J. 

 Campbell, Melbourne, was communicated. — Dr. Buchan dis- 

 cussed a difference between the diurnal barometric curves at 

 Greenwich and at Kew. — Dr. Sang communicated a paper on 

 the general formulae for the passage of light through a spheric- 

 ally arranged atmosphere. — Dr. Buchan gave an account of a 

 remarkable barometric reading at the Ben Nevis Observatory 

 on April 8, 1890.— Prof. Crura Brown read the third part of a 

 paper, written by himself in conjunction with Dr. James Walker, 

 on synthesis by means of electrolysis. 



July 7.— Sir William Thomson, President, in the chair.— The 

 Victoria Jubilee Prize for 1887-90 was presented to Prof. Tait 

 for his work in connection with the Challenger Expedition and 

 his other researches in physical science. The Keith Prize for 

 1887-89 was presented to Prof Letts for his researches into the 

 organic compounds of phosphorus. The Neill Prize for 1886-89 

 was awarded to Mr. Robert Kidston for his researches in fossil 

 botany. — Sir W. Thomson read a paper on the submarine cable 

 problem, with electromagnetic induction. The solution of the 

 problem with intermittent or alternating currents of period so 

 long that the distribution of current over a given cross-section 

 of the core is uniform, is already well known. Sir W, Thom- 

 son extends the solution, through all intermediate stages, to the 



