RECENT ADVANCES IN SCIENCE 531 



Hydrodynamics and Sound 



Delage, Y., Sur un tube de Pitot int^grateur pour le mesure de la vitesse 



moyenne des courants variables, Comptes Rendus, 170, 1920, 213-8. 

 Cook, G., An Experimental Determination of the Inertia of a Sphere moving 



in a Fluid, Phil. Mag. (vi), 39, 1920, 350-2, obtains an addition to the 



inertia of 0-46 times the mass of an equal volume of fluid, the theoretical 



value being o-5. 

 Metzner, p. {Phys. Zeit., 20, 1919, 536-42), discusses stream motion in 



fluids caused by rotating bodies. 

 Scheuerman, R. [Ann. Phys., 60, 1919, 233-59), discusses the jet of falling 



liquid . 

 ViLLAT, H., Sur certains mouvements cycliques avec ou sans tourbillons, 



Comptes Rendus, I7O, 1920, 449-51. 

 ViLLAT, H., Sur le mouvement variable d'un fluide ind^fini avec sillage en 



presence d'un corps solide, ibid., 170, 1920, 653-5. 

 Hicks, W. M., Mass carried Forward by a Vortex, Phil. Mag. (vi), 38, 1919. 



597-612. 

 Nagaoka, H., Vibration of Cylinder in Fluid Flow, Proc. Phys. Math. 



Soc. Jap., 1919, 277-83. 

 Cowley, W. L., Fluid Motion and Viscosity, Engineering, 109, 1920, 101-2. 

 DuTT, B., On the Steady Motion of a Viscous Fluid due to the Rotation of 



two Rigid Bodies about Arbitrary Axes, Bull. Calc. Math. Soc, x, 1919, 



43-61. 

 Pol, B., On the Motion of an ElUpsoid of Revolution in a Viscous Fluid, 



ibid., X, 1919, 81-94, 

 Harrison, W. J., The Hydrodynamical Theory of the Lubrication of a 



Cylindrical Bearing under variable Load, and of a Pivot Bearing. Trans. 



Camb. Phil. Soc, xxii, 1920, 373-88. 

 Dasgupta, S., Some Cases of Tidal Oscillations in Canals of Variable 



Section, Bull. Calc Math. Soc, x, 1919, 105-16. 

 Banerji, S., On Surface Waves and Tidal Waves near a Promontory, ibid., 



X, 1919, I-IO. 

 Raman, C. V., and Dey, A., On the Sounds of Splashes, Phil. Mag. (vi), 



39, 1920, 145-7. 

 Raman, C. V., and Kumar, S., Musical Drums with Harmonic Overtones, 



Nature, 104, 1920, 500. 

 Rayleigh, Lord (the late). On Resonant Reflexion of Sound from a Per- 

 forated Wall, Phil. Mag. (vi), 39, 1920, 225-33. 

 Wilson, H. A., The Theory of Receivers for Sound in Water, Phys. Rev., 



XV, 1920, 178-205. 

 Waetzmann, E., Theoretisches uber den Schalldruck, Phys. Zeit., xxi, 1920, 



122-8. 



ASTRONOMY. By H. Spencer-Jones, M.A., B.Sc, Royal Observatory, 

 Greenwich. 



The Angular Diameters of the Stars. — In these notes recently 

 (Science Progress, 15, 180, 1920) reference was made to the 

 appUcation of interference methods, at the Mount Wilson 

 Observatory, to the measurement — with the aid of the 1 00-inch 

 telescope^ — of the separation of the components of Capella. It 

 was also shown that the same principles are adapted to the 

 measurement of the angular diameters of small satellites or 

 asteroids, and the application of the method to the determina- 

 tion of the angular diameters of stars was foreshadowed. This 



