i88 SCIENCE PROGRESS 



regardless of the fact that the same mathematical methods 

 are required in other branches of mechanics and physics. 

 Forsyth urges the need of an English book hke Weber's edition 

 of Riemann's Partial Differential Equations of Mathematical 

 Physics, and says : "It would be just a useful treatise of 

 natural philosophy, written by one who knows his mathe- 

 matics, his mechanics, and specially his physics." 

 The following papers should be noted : 



Buckingham, E., Notes on the Methods of Dimensions, Phil. Mag., (vi), 



42, 1 92 1, 696-719. 

 Delassue, E., Sur une consequence des lois de frottement, Comptes Rendus, 



172, 1921, 1335-7- 

 FucHS, S., Zur Theorie des Gleit- und Rollwiderstandes der festen Korper, 



Phys. Zeit., xxii, 1921, 173-7, 213-18, where the phenomena of shding 



and roUing friction are explained by hydrodynamical suction of the 



air-layer between the bodies. 

 Frontard, M., Cycloides de glissement de terres, Comptes Rendus, 174, 1922, 



526-9 ; see also 740-2, 930-3. 

 Guillaumin, G., Sur I'^quihbre des talus en terra coh6rente, ibid., 174, 



1922, 1165-7; see also 1278-80, 1410-13. 

 RliMOUNDOS, G., Sur les deformations planes et le probl^me de la pouss6e 



des terres, ibid., 174, 1922, 929-30 ; see also E. Goursat, ibid., 1049, 



and G. R^moundos, ibid., 1533-4. 

 Webster, A. G., On Steering an Automobile around a Corner, Proc. Nat. 



Acad. Sci., U.S.A., 8, 1922, 100-6, where the path is considered for 



turning through a right angle without skidding. It is shown that the 



safe speed is just less than 10 miles per hour. 

 Searle, G. F. C, An Experiment Illustrating the Conservation of Angular 



Momentum, Proc. Camb. Phil. Soc, xxi, 1922, 75-9. 

 Stokes, G. D. C, An Analytical Treatment of the Cam Problem, Proc. Edin. 



Math. Soc, xxxix, 1921, 7-12. 

 Baker, W. C, A New Gyroscopic Construction in Simple Vectors, Phys. 



Rev., xix, 1922, 323-8. 

 Le Rolland, P., Etude de I'oscillation du pendule par le m^thode photo- 



graphique (Influence de la suspension), Ann. de Phys., xvii, 1922, 165-381. 

 Jones, A. T., The Motion of a Simple Pendulum after the String has become 



Slack, Phil. Mag., (vi), 41, 1921, 809-13. 

 Jackson, L. C, Variably Coupled Vibrations : Gravity Elastic Combina- 

 tion II. Both Masses and Periods Equal, Phil. Mag., (vi), 40, 1920, 



329-42. 

 Barton, E. H., and Browning, H. M,, Triple Pendulums with Mutual 



Interaction and the Analogous Electric Circuits, ibid., (vi), 40, 1920, 



611-18; 42, 1921, 17-34- 

 Morton, W. B., and Tobin, T. C, Notes on Times of Descent under Gravity, 



suggested by a Proposition of Galileo's, ibid., (vi), 41, 1921, 225-39. 

 Harrison, W. J., Notes on the Theory of Vibrations : (i) Vibrations of 



Finite Amplitude, (2) A Theorem due to Routh, Proc. Camb. Phil. 



Soc, XX, 1920, 83-7. 

 Baker, B. B., and Ross, E. B., The Vibrations of a Particle about a Position 



of Equihbrium, Proc. Edin. Math. Soc, xxxix, 1921, 34-57. 

 TiERCY, G., Sur les courbes orbiformes, Leur utilisation en m6canique, 



Toh. Math. Jour., 18, 1920, 90-115; the curves are curves of constant 



width, 

 Upadhvaya, p. O., Tautochronous Motion, ibid., 20, 1921, 32-6. 

 Iwatsuki, T., On Plane Motions, ibid., 20, 1922, 131-60. 



