542 



NATURE 



{April 19, 1877 



radiometer, by M. Neesen. — Researches on the motions of 

 radiating and irradiated bodies, by M. Zollner. — On the deter- 

 jnination of the principal and focal points of a lens-system, by 

 M. Hoppe. — On thermo-electric determinations of temperature, 

 by M. Rosenthal. — On the nature of gas-molecules, by M. 

 Boltzmann. 



Beibliitter zu den Annalen dtr F/iysik und Chemie, Bandi. Stiick 

 2. — We note here a useful paper on recent experiments with the 

 radiometer and their explanation ; also a doctorate-dissertation by 

 M. Lorentz, on the theory of reflection and refraction of light. 



From the Naturforscher (February) we note the following 

 papers : On the most refrangible part of the solar spectrum, by 

 T. L. Soret. — On the distribution of the electric current in con- 

 ductors under decomposition, by R. Lenz. — On the southern 

 shore of the noithern diluvial sea, by Herr Credner. — On the 

 mixed occurrence of different vegetations, by Oscar Drude. — 

 On the nature of the substance which emits light in the flames 

 of hydrocarbons, by Karl Heumann. — On a prehistoric steppe in 

 the Prussian province of Saxony, by A. Nehring. — On the 

 history of Tertiary deposits in South-eastern Europe, by M. 

 Tournoiier. — On ttie differences in the chemical structure and in 

 the digestion of higher and lower animals, by F. lioppe-Seyler. 

 — On a relation of chemical structure to the power of polarising 

 light, by G. J. W. Bremer. — On the conduction of heat by 

 liquids of different densities, by E. Sacher. — On the behaviour 

 of palladium in the alcohol flame, by F. Wohler. 



The Archives des Sciences Physiques et Nattirelles (January), 

 contains the following original papers : — On the tendrils of 

 climbing plants, by Casimir de Candolle (see our note on this 

 paper). — On the origin of the ancient alluvium, by Ernest Favre. 

 — On static electricity, by E. Mascart. — Description of Niphar- 

 gus puteanus, var. Forellii, by Alois Humbert (see our note on 

 this paper). — Some researches made in the physiological labo- 

 ratory of Geneva ; on the formation of pepsine before and after 

 death, by Prof. Schiff. — Note on the effect of the irritation of a 

 nerve through which a constant electric current is passing, by 

 Dr. B. F. Lautenbach. 



The yournal of the Russian Chemical and Physical Societies 

 (vol. viii., part 9, December, 1876), contains the following 

 papers : — On the action of bromine upon acetone, by N. Soko- 

 lowsky. — Synthesis of a oxybutyric acid, by S. Przibytek. — On 

 the pinacoline of mcthylethyl- acetone, by G, Lawrinowich. — On 

 the synthesis and properties of diallyl-carbinol, by M. Saytzew. 

 — On the action of the iodides of ethyl and allyl upon formiate 

 of ethyl, by the same and J. Kanonnikow. — On the synthesis 

 and the properties of dimethylallyl carbiuol, by the same and 

 M. Michail. — Theoretical researches concerning the distribution 

 of static electricity on the surface of conductors constituted of 

 heterogeneous parts, by D. Bobylew. — On electric rays, by O. 

 Chwolson. 



Reale Islitnto Lonibardo di Science e Lett ere, Rendiconti, vol. x. 

 fasc. 2. — On the co-ordinates of points and of lines in a plane, 

 and of points and planes in space (continued), by M. Casorati. 

 — Case of mammary hypertrophy, by M. Scarenzio. — Resalls 

 of observations on the amplitude of the daily oscillations of the 

 magnetic needle in 1875 ^"'^ 1876, at the Observatory of Brera, 

 in Milan, by M. Schiaparelli. — On some differential equations 

 with algebraic integral, by M. Brioschi. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, March 8. — "Notes on Physical Geology," 

 by the Rev. Samuel Haughton, M.D. Dublin, D.C.L. Oxon., 

 F.R.S., Professor of Geology in the Uuiversity of Dublin. 



No. I. — Preliminary Fortnuhe relating to the Interttal Change 

 of Position of the Earth's Axis, arising from Elevations and 

 Depressions caused by Geological Changes. 

 In this paper the author proves the following preliminary 



formulae, necessary for the further discussion of his subject : — 



- Tan 2© = 935-6 p sin 2 A. . . . . (i) 

 where p is the ratio of the weight of an elevated mass to the 

 weight of the whole earth ; 



A is the latitude at which the elevation takes place, and 

 Q is the final displacement of the earth's axis of rotation. 



- rO = 14*11 (cos^ A.' - C0b*A) ... (2) 



where r is the displacement of the pole in English miles, caused 

 by a continental slip of 5° longitude in breadth, and lying be- 

 tween the higher and lower latitudes of \ and \'. 



In proving the equations the author distinguishes between 

 three level surfaces, viz. — • 



1. The surface of the sea. 



2. The zero surface of the solid earth. 



3. The zero surface, corrected for the weight of the ocean. 

 The zero plane, from which the elevations are measured, is 



the surface of the ellipsoid similar to the sea surface, and con- 

 taining the same volume as the total solid matter of the globe. 

 It is thus found, assuming the mean height of the continents 

 above the sea-level at about 1,000 feet, and the mean depth of 

 the ocean at about two miles, we have, in miles, 



2'2L 



W -f L 



where x is the height of the zero plane above the present mean 

 sea-bottom, and L, W are the areas of land and water ; 



L = 52 millions of square miles. 

 W = 145 

 Substituting we find — 



X = 0*58 mile. 



The zero plane, therefore, or original surface of the solid earth, 

 before it became wrinkled by geological forces, lies at a depth of 

 I "42 mile below the sea-level. In using the equations we must 

 therefore write — 



Elevation = -f i "62 mile (continent). 

 Depression — — 0*58 ,, (ocean). 



In calculating the motion of the pole caused by the ocean ex- 

 cavations, the weight of the sea water must be considered, and, 

 by chance, it happens that the weight of the sea-water some- 

 what more than counter-balances the weight of the surface-rock 

 excavated ; so that the depression of the ocean-bottoms of the 

 earth beneath the zero plane have had little or no effect in shifting 

 the position of the pole. 



Assuming 1-026 and 2-75 as the densities of sea-water and 

 surface-rock, we have for the excess of weight of water added 

 above that of rock excavated ; expressed in depth of rock, in 

 miles — 



2 X 1-026 -0-58 X 2-75 ., 



~ =017 mile. 



275 



The introduction of the weight of the s?a will thus give us 

 (raising the zero plane by 0-17 of a mile) — 



Elevation = + i -45 mile (continent), 

 Depression = 000 ,, (ocean). 



No. II, — On the Amount of Shifting of the Eai-th's Axis, already 

 caused by the Elejation of the existing Continents. 



Having shown in the preceding note that the motion of the 

 earth's axis caused by the geological wrinkling of the earth's 

 surface depends (in consequence of the weight ot the sea- water) 

 only on the continents, it remains to calculate the numerical 

 amount of change of axis produced by each of the existing con- 

 tinents. 



For this purpose the author selects the following meridians for 

 the co-ordinates Y and X of the motion : — 



Reckoning the longitudes eastward, round the whole circum-j 

 ference of the earth, the equation (2) gives — 



rQ — — 14-11 (cos^A' — cos^A), 



in which the meridian of each 5" of longitude is used. A' and \\ 



being the lowest and highest degrees of latitude of the land oa^ 



each meridian. 



The expression cos^ A' — cos' A is found by observation on the^ 



globe, and resolved into its components X and Y, regarding thej 



North Pole as the axis moved. 



The equation (2) is then used (by quadratures) to determioe^ 



the total effect of each continent taken separately. The tables] 



of quadratures are given in the paper, and the final results are- 

 Displacement of North Pole caused by each continent. 



