January 19, 191 i] 



NATURE 



38, 



The descent of a sphere in a viscous liquid was studied 



V Basset in 1887, but the equation of motion was only 



ntegrated by successive approximation. Since that time 



he subject has been discussed in the Alti dei Lincei for 



107 by Prof. Picciati and Dr. Tommaso Boggio. In the 



Juarterly Journal of Pure and Applied Mathematics, 



so. 164 (1910), Mr. Basset gives a general investigation 



f the problem, based on the work of the two Italian 



writers. One notable feature of the work is that the 



iscosity enters into the Stokes' current-function solution 



: a way that it did not enter in the earlier solutions of 



".e problems. 



In a paper on the imaginary in geometry-, contributed 



^ the University Studies, Lincoln, Nebraska, x., 1., Prof. 



Ellery W. Davis discusses geometrical properties connected 



with a mode of representing points in two-dimensional 



space the coordinates of which are both complex variables. 



He takes a so-called " black " point P' the coordinates 



: f which are the real parts of the variables, and from it 



iraws a " red vector " the compounds of which are the 



maginary parts, the extremity being a " blue " point P* 



he coordinates of which measure the real parts plus the 



laginary coefficients. 



I The Revue scientifique for December 31, 1910, contains 

 ||e address delivered by M. H. Le Chatelier at the College 

 France on December 18 in connection with the cere- 

 jnies commemorating the centenary of the birth of 

 Jnault. In the course of his address M. Le Chatelier 

 ferred to several facts in the early life of Regnault not 

 toerally known. An orphan without means, he spent his 

 juth as an assistant in a fancy bazaar, and at the age 

 twenty-two entered as a student at the Ecole des Mines. 

 |e rose immediately to a prominent position as one of 

 most promising pupils, and at the qualifying examina- 

 3ns in May, 1834, after two years only of study, he 

 ssed brilliantly. For some strange reason the Govern- 

 ent refused to nominate him student engineer along with 

 is successful fellow-students, but insisted on a further 

 vo years' course at the Ecole. During this period he 

 lised himself by his chemical researches to the front rank 

 chemists, and it was only on the appointment of a 

 jvernment commission on the steam engine in 1843 that 

 commenced that series of measurements in the domain 

 physics which for accuracy remained unique for half a 

 entur}-. 



In N.ature for August, 11, 1910, we directed the atten- 



>n of our readers to a communication to the Vienna 



|cademy of Sciences, which appeared in the Physikalische 



ilschrift for July 15, and gave a preliminary account of 



l»e measurements of quantities of electricity less than the 



Jectron or " atom of electricity," by Dr. F. Ehrenhaft, of 



"he University of Vienna. The complete account of the 



Measurements is now available in the Siizungsberichte of 



academy for May, 1910. Since our previous note, Prof. 



[illikan has published in Science for September, 1910, an 



count of his measurements of the charges on drops of 



il produced by an " atomiser " or sprayer. He concludes 



from them that the atomic charge of electricity is 



49x10-" electrostatic units. Dr. Ehrenhaft points out 



in his complete paper that many of Prof. Millikin's results 



do not fit in with his conclusion. The June (1910) number 



of the Sitzungsberichte contains Dr. K. Przibram's 



measurements of the charges on the fine particles of mists 



produced by electrolysis of a solution of potassium hydrate, 



by the spark discharge in moist air, by hydrochloric acid, 



or by phosphorus in moist air. His resuhs confirm those 



of Dr. Ehrenhaft, so that there is a serious diflference of 



<q)inion between the Viennese and other observers on the 



NO. 2151, VOL. 85] 



fundamental question of the existence of atomic charges uf 

 electricity. 



The paper read by Major O'Meara, C.M.G., on sub- 

 marine cables for long-distance telephone circuits, at the 

 Institution of Electrical Engineers on January 12, when 

 Mr. Herbert Samuel, the Postmaster-General, was present, 

 will be welcomed by electrical engineers. The paper gave 

 in the first place a brief description of the first telephone 

 cable of notable length ; and after touching shortly on the 

 differences in subsequent cables laid across the Channel — 

 which varied very little from the original — proceeded to 

 describe the latest telephone cable laid last }ear between 

 Dover and Cape Gris Nez. This cable was specially 

 designed to improve the clearness of speech over the line, 

 and also to enable more distant parts of the Continent to 

 be in direct communication with England. To overcome 

 the indistinctness, to which all long-distance telephone 

 cables are liable, small induction coils are inserted in the 

 cable. The theory of this was first propounded by Messrs. 

 Heaviside and Pupin, and is embodied in the present " coil 

 loaded " cable. Two double coils are required for the four 

 conductors and are inserted at a distance of one knot 

 (1153 miles) apart, each coil being just under six ohms 

 resistance. The two coils nearest the ends of the cable are 

 only half a knot from the terminal instruments, this having 

 been found to give the best results. It is essential, having 

 regard to the maintenance of these cables, that the coils 

 should be evenly distributed, as in repairing cables inter- 

 mediate lengths have to be inserted. So long as the coil 

 spacing is not altered beyond five per cent, on either side, 

 no noticeable impairment to speech will take place. The 

 importance of this fact will be appreciated when the list 

 of repairs on existing telephone cables is taken into 

 account. It was doubtful when the cable was designed as 

 to how the mechanical difficulty of securing the coils in 

 the cable would be overcome, owing to the increase of size 

 at the points where the coils are inserted, and also the 

 difficulty of the increased thicknesses passing over the 

 drums when laying the cable. These difficulties were 

 successfully overcome and a special paying-out drum was 

 employed, the cable being payed out without passing it 

 under the dynamometer wheel. The paper gives a full 

 description of the laying of the cable ; and the complete 

 specification of the cable is contained in one of the many 

 appendices attached thereto. L"nder the previous existing 

 conditions, conversation could be carried on over a 

 distance of 250 miles, but with the new " coil-loaded " 

 cable a distance of 850 miles is possible. 



TiTB current number (January 10) of the Comptes rendus 

 of the Paris Academy contains an account of a new general 

 method of preparing anhydrous metallic chlorides, bv Ed. 

 Chauvenet. The method recently proposed by Matignon 

 and Bourion, based on the use of a mixture of chlorine 

 and sulphur chloride, is efficient, but the method now^ 

 proposed is simpler in that phosgene is used, a substance 

 commercially obtainable in the liquid form in bombs. The 

 oxide of the metal is placed in a boat, and heated in a 

 slow stream of the carbonyl chloride ; the metallic chloride, 

 if it is volatile, sublimes a little in advance of the boat in 

 crystals, the temperature required varying between 350° C. 

 and 650** C. Of the numerous oxides tried only silica was 

 unacted upon, a fact which will be of seri'ice in separating 

 siilca from other metallic oxides, such as the oxides of 

 tungsten, tantalum, or titanium. Titanium and tungsten 

 furnished oxychlorides, but in all the other cases examined 

 the pure anhydrous chloride was obtained. 



At the students' meeting of the Institution of Civil 

 Engineers, held on January 6, Mr. G. F. Davidson read a 



