30 



NATURE 



[March 3, 192 1 



calated in bands in the gneisses of portions of the 

 hundred of Lincoln is a series of dolentes which have 

 suffered a metamorphism of the highest grade. 



Zoological Society, February 8. — Prof, E. W. Mac- 

 Bride, vice-president, in the chair. — Dr. C. F. Sonntag : 

 The comparative anatomy of the tongues of the Mam- 

 malia, family Simiidse.— D. M. S. Watson : Basis of 

 classification' of the Theriodontia. 



Royal Meteorological Society, February i6. — Mr. R. H. 

 Hooker, president, in the chair.— M. de Carle S. 

 Salter : A new method of constructing average 

 monthly rainfall maps. For the present purpose 

 a new series of isomeric maps for the period 

 1881-1915 has been prepared, on the scale of 

 20 miles to i in., from 550 records. A map 

 showing the distribution of average annual rain- 

 fall for thirtv-five years has been compiled on the 

 same scale (i) frorn Dr. H. R. Mill's survey maps 

 on the scale of 2 miles to i in. prepared fVom all 

 available data, and (ii) by computing 1700 additional 

 average values for the districts not yet surveyed. The 

 twelve monthly isomeric maps and the annual map 

 were ruled in a network of squared lines 10 miles 

 apart, and values interpolated at each of the points of 

 intersection The twelve percentage evaluations for 

 each point were collected and severally applied to the 

 value from the annual map, thus obtaining twelve 

 monthlv rainfall values applicable to the point in ques- 

 tion. The latter were plotted on a fresh series of 

 ruled maps, together with the actual average values 

 for the 550 stations originally utilised, and the whole 

 were used as a basis for isohyetal lines. The whole 

 gave 2573 values for each month, and left no space 

 of more than 10 miles without some means of control- 

 ling- the drawing of the lines. The paper discusses 

 the limits of error introduced by the method. — G. A. 

 Clarke : An unusual pilot-balloon trajectory. A bal- 

 loon observed by one theodolite was found to pursue 

 a course so erratic that its results, if calculated by 

 the method applicable to the one-theodolite ascents, 

 would have shown a wind of more than 1 10 miles per 

 hour from W.S.W. at 2.<oo ft., with a return wind of 

 similar velocity from E.N.E. only 500 ft. higher. 

 Such conditions in the atmosphere being extremely 

 improbable, an endeavour was made to deduce the 

 magnitude of the vertical currents, and it was found 

 that the path described could be accounted for by a 

 descending .current of about 6 miles per hour, fol- 

 lowed by an ascending one of somewhat similar 

 velocity. 



Cambridge. 



Philosophical Society, February 7. — Prof, Seward, 

 president, in the chair. — G. E. Brlggs : The develop- 

 ment of photosynthetic activity during germination. — 

 Prof. G. H. Hardy : A theorem concerning summable 

 series. — E, A. Milne : Vectors and tensors. The usual 

 intuitive concept of a vector useful in three dimen- 

 sions no longer serves in four dimensions, and a more 

 precise definition is required, in which, however, the 

 notion of a permanency independent of any particular 

 co-ordinate system is preserved. Consider the class 

 of co-ordinate systems and the class of representa- 

 tions of a particular vector (by means of sets of com- 

 ponents) associated with them : it is suggested that a 

 vector be defined as the class of such correlated sets. — 

 H. C. Pocklington : (a) Standing weaves parallel to a 

 plane beach, (b) A kinetic theory of the universe.— 

 Prof. H. F. Baker : (a) A configuration in four dimen. 

 sions. (b) The representation of a cubic surface on a 

 quadric surface, (c) Delaunay's method in planetary 

 theory, (d) A periodic motion in dvnamics. 



February 21. — Prof. Seward, president, in the 

 chair.— Dr. Hartridge : The present position of the 

 Helmholtz theory of hearing. 



NO. 2679, VOL. 107] 



Manchester. 

 Literary and Philosophical Society, January 11. — Mr* 

 Francis Jones, vice-president, in the chair. -^Dr. A. A. 

 Mumford : Testing and grading of health and physical 

 fitness. The author urged the necessity of fresh 

 physical fitness tests for school-children — the present 

 tests mainly dealt wirii exceptional children, such as 

 the deformed, diseased, and mentally unfit — based on 

 the capacity to put forth effort, and thus considering 

 the work of the heart, lungs, and the nervous system. 

 The tests, brought into prominence by the work of 

 the Air Force, mainly concerned breathing, and were 

 now being adapted to boys in the Manchester Gram- 

 mar School. The first test, dealing with the amount 

 of air used in respiration, was measured by the spiro- 

 meter ; the second, dealing with the force of respira- 

 tion, was measured by pressure against a columa of 

 mercury ; and the third concerned the movements of 

 the chest, which could be examined bv means of a 

 specially designed waistcoat. 



January 25. — Sir Henry A. Miers, president, in the 

 chair. — W. E. Alkins, M. Cook, and J. Harwood : 

 Variation in Sphaeria — (i) S. lacustre, Muller; (ii) 5. 

 corneum, Linnd ; (iii) 5. pallidum, Graj'. These three 

 papers were mainly confined to the presentation of 

 results and a comparison of species, a general dis- 

 cussion of the significance of the results being re- 

 served for a fourth and concluding paper on 

 S. rivicola. Two hundred specimens of 5. lacustre 

 from Three Lows, North Staffordshire, and five 

 hundred each of S. corneum and S. pallidum from 

 the Ashton and Guide Bridge Canal, near Dukinfield 

 Station, had to be examined. The authors have 

 studied the variation of width, length, and thickness. 



Paris. 

 Academy of Sciences, February 7. — M. Georges 

 Lemoine in the chair. — G. Gouy : Systems of prisms 

 with parallel edges. — R. Birkeland : The resolution of 

 the general algebraic equation by hypergeometric 

 functions of several variables. — E. Jouguet : The case 

 of Poincar6 in the theory of elasticity. Poincare has 

 studied the small deformations of an elastic solid, 

 starting with an initial state in which the tensions are 

 not zero. The author examines some thermodynamic 

 properties of elastic solids with similar deformations. 

 — A. Guillet : A chronograph recording photo- 

 graphically for the measurement of short periods in 

 harmonic motion or with circular uniform movement 

 by means of Lissajous's figures. — C. Fery : A battery 

 depolarised by air. A modification of the Leclanche 

 cell. The zinc is in the form of a horizontal disc 

 placed at the bottom of the cell ; the carbon is a 

 cylinder the lower flattened edge of which is imme- 

 diately above the zinc plate. The removal of the 

 polarising hydrogen by the air causes currents between 

 the upper and lower ends of the carbon cylinder. It 

 is claimed for this battery that no peroxide of man- 

 ganese is required, local action is absent, and its 

 e.m.f. during use is very constant. It has received 

 practical application in the French Posts and Tele- 

 graphs Department, and it has been shown that it lasts 

 three times as long as the old form. — P. Chevenard : 

 The expansion anomaly accompanying the magnetic 

 transformation of pyrrhotine and magnetite. In the 

 neighbourhood of 320° C. pyrrhotine suddenly in- 

 creases in length, corresponding very probably to a 

 true allotropic transformation analogous to the change 

 of o-iron into 7-iron. This hypothesis is confirmed by 

 the fact noted by Weiss, that the magnetisation co- 

 efficient of pyrrhotine is nearlv independent of the 

 temperature round about 320° C. Magnetite also 

 shows an anomaly in expansion at 570° C. — a tem- 

 perature near the magnetic Curie point determined by 



