,2 J. 2 



NATURE 



[May i6, 1918 



function can be ascribed to such enlargements, other 

 than " the normal one of transmission and reflex action 

 in an unusual degree." The discussion involves in- 

 teresting remarks on the mode of life of the large 

 Dinosaurs. 



An interesting review of field observation and labora- 

 tory work on the problems of dynamic metamorphism 

 in rock masses is given by Sir Jethro Teall in the 

 Proceedings of the Geologists' Association (vol. xxix., 

 p. I, 1918). The famous Scourie dyke is again con- 

 sidered, and the flow of the Lizard rocks under pres- 

 sure is imitated experimentally in blocks of hetero- 

 geneous clay. 



An important memoir by Messrs. A. S. Kennard and 

 B. B. Woodward on "The Post-Pliocene Non-marine 

 Mollusca of Ireland " appears in the Proceedings of the 

 Geologists' Association (vol. xxviii., p. 107, 1917). The 

 authors conclude that, "with the exception of two or 

 three species which may have been accidentally intro- 

 duced by man, all the species existed in Ireland in pre- 

 Glacial times and survived the Glacial period." The 

 Chara deposits often found beneath peat are held to 

 indicate a warm epoch, when they were formed in 

 shallow meres liable to desiccation in the hot summers. 

 Under such conditions the plants become white and 

 brittle, and break up to form a "marl." The raised 

 beaches of the north-east belong to the same epoch. 

 A damper time followed; but the cold epoch postulated 

 in Prof. F. J. Lewis's series is not recorded by the 

 mollusca. A just tribute is paid to the unflagging 

 work of Mr. R. Welch, of Belfast. 



The Boletin oficial de minas y metalurgia publishes 

 a report on the mineral production of Portugal (quoted 

 in Le Ginie Civil for April 27). The minerals ex- 

 ploited have been particularly uranium (1307 tons), 

 wolfram, tin, copper, and iron. The total production 

 of metals in Portugal in 19 14 was only 455 tons, as 

 against 845 tons the previous year. 



Elektrotechnik und Maschinenbau for October 24, 

 19 17, describes new types of platinum-iridium thermo- 

 couples for recording rapid changes of temperature. 

 One type consists of wires 0-02 mm. in diameter, in 

 the proportion of sixty-five parts platinum and thirty- 

 five parts iridium. The maximum range of the com- 

 bination considered is 1850° C. 



In the Zeitschrift des Vereines deutscher Ingenieure 

 for December 8 last, Max Berlowitz discusses the im- 

 provements that have been made in the design of 

 micromanometers. He also gives a detailed descrip- 

 tion of a recent instrument invented by Rosenmuller, 

 which has the great advantage of a fixed zero. The 

 author also describes a new method of standardising 

 the micromanometer, and gives a table of simplified 

 calculations for use with the instrument. 



Prof. Doelter, in Die Zeit (March 13), describes 

 the phosphate deposits of the Ukraine. These deposits 

 occur in the Silurian formation, chiefly in Podolia and 

 Bessarabia, and also to a great extent on the banks 

 of the Dniester and the Ladova, where it is obtained 

 in lumps. The mineral is phosphorite, and contains 

 considerable calcium phosphate, which yields 27I per 

 cent, of phosphoric acid. There are numerous phos- 

 phorite deposits in other districts. 



A German patent has been granted {Elektrotechnik 

 und Maschinenbau, April 25, 19 17) for manufacturing 

 electric condensers by covering a surface of metal with 

 an elastic medium that adapts its shape to that of 

 the metal. The tissue is then impregnated with a 

 substance to render it dielectric, and a second sheet 



NO. 2533, VOL. lOl] 



of metal forms the other plate. German Patent 

 No. 291,923 (Zeitschrift fiir Mechanik und Optik, 

 February i, 1917) describes a condenser formed by a 

 glass dielectric upon which a very fine film of lead 

 is squirted. 



Messrs. Blackie and Son, Ltd., are publishing in 

 two volumes, under the title of " Applied Optics : The 

 Computation of Optical Systems," an edited transla- 

 tion, by J. W. French, of Steinheil and Voit's " Hand- 

 buch der angewandten Optik." Vol. i. is ready. 

 Vol. ii., which is in preparation, will deal with the 

 determination of refractive indices and dispersions 

 and the computation of achromatic prisms, with the 

 cornputation of doublet objectives ; also with the dis- 

 cussion of the aberrations of different combinations. 

 In addition, it will contain appendices on "The Deter- 

 mination of the Refractive and Dispersive Powers of 

 Various Media" and on "The Trigonometrical For- 

 mulas for the most General Case of the Refraction of 

 Light by a System of General Surfaces." 



OUR ASTRONOMICAL COLUMN. 



Nova Monocerotis.— Additional particulars of the 

 new star in Monoceros, which was discovered by Wolf 

 on Februarv 4 (Nature, vol. ci., p. 52), are given in 

 Popular Astronomy for April (vol. xxvi., p. 2S2). The 

 position of the star for 19180, as determined by Prof. 

 Barnard, is given as R.A. 7h. 22m. 46-933., decl. 

 — 6° 30' 347". According to observations made at the 

 Lick Observatory, the spectrum has reached the 

 nebular stage, consisting of extremely broad bright 

 bands of hydrogen, with the nebuHum lines moderately 

 strong and absorption near the centres of the' green 

 bands'. Photographs taken at Harvard on February 2 1 

 show the bright hydrogen lines a to t,, and bright 

 lines also appeared at wave-lengths 4363, 4520, 4686, 

 5007, 5440, 5630, and 5750. 



The Atomic Weight of " Nebulium." — In a more 

 complete investigation of the periods of vibration of a 

 single-ring atom, takmg account of the magnetic and 

 associated mechanical forces on an electron due to its 

 motion. Prof. J. W. Nicholson has made a more precise 

 calculation of the atomic weight of "nebulium" 

 (Monthly Notices, R.A.S., vol. Ixxviii., p. 349). Adopt- 

 ing Wright's values for the two lines A 500689 and 

 A 4363-37, it results that m/M = oooo4i5, where m is 

 the mass of the electron and M that of the atom of 

 nebulium. Since the mean of the best determinations 

 of the corresponding ratio w/H for the hydrogen atom 

 is 0000545, it results that the atomic weight of 

 nebulium is 1-31, the possible error being unity in the 

 last figure. From observations of the limiting order 

 of interference for the line A 5007, Prof. Fabry had 

 previously shown that the atomic weight was probably 

 between those of hydrogen and helium. 



Hyderabad Astrographic Catalogue. — ^The work 

 on the astrographic- catalogue at the Nizamiah 

 Observatory, Hyderabad, has been carried on with 

 extraordinary vigour since the appointment of the 

 present director, Mr. R. J. Pocock, in 1914. The 

 seven zones from 17° to 23° south declination were 

 originally assigned to the Santiago Observatory, but 

 on account of the long delay in commencing operations 

 the Hyderabad Observatory was afterwards invited 

 to undertake the zones. -17° to —20°. Little was 

 done before Mr. Pocock took charge, but the telescope 

 was got into working order and regular work on the 

 catalogue commenced in December, 1914. The first 

 volume of the catalogue has just been issued, com- 

 prising measures of rectangular co-ordinates and dia- 

 meters of 63,436 star^mages on plates with centres 



