KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 



TE AMSTERDAM. 



PROCEEDINGS 



VOLUME XX 

 N°. 8. 



President: Prof. H. A. Lorentz. 

 Secretary: Prof. P. Zeeman. 



(Translated from : "Verslag van de gewone vergaderingen der Wis- en 

 Natuurkundige Afdeeling," Vol. XXV and XXVI). 



CONTENTS. 



C. EASTON: "Periodicity of Winter Temperatures in Western Europe, since A. D. 760". (Communi- 

 cated by Dr. J. P. VAN DER STOK), p. 1092. (With one platei. 



W. J. A. SCHOUTEN: "On the Parallax of some Stellar Clusters." (First communication). Communi- 

 cated by Prof. J. C. KapTEIJN), p. 1108. 



A. H. W. AteN: "The Passivity of Chromium". (Second Communication). (Communicated by Prof. 

 A. F. HOLLEMAN), p. 1119. 



W. Reinders and L. Hamburger: "Ultramicroscopic investigation of very thin metalfilms obtained 

 by evaporation in high vacuum". II. (Communicated by Prof. J. BöESEKENi, p. 1135. (With one 

 plate). 



P. G. Cath and H. Kamerlingh OnneS: "On the measurement of very low temperatures. XXVII. 

 Vapour-pressures of hydrogen in the neighbourhood of the boiling point and between the 

 boiling point and the critical temperature. (Continued), p. 1155. 



P. G. Cath and H. Kamerlingh onnes: "Isothermals of monatomic substances and their binary 

 mixtures. XIX. Vapour-pressures of neon between the boiling point and the critical point", p. 1160. 



P.O. Cath, H. Kamerlingh Onnes and J. M. Burgers: "On the measurement of very low temperatures. 

 XXVIII. Comparison of the platinum and the gold resistance thermometers with the helium- 

 thermometer", p. 1163. 



Ernst Cohen: "The Allotropy of Cadmium". VI, p. 1177. 



J. BÖESEKEN and Chr. van Loon: "On the Hydrindene-1.2-diols". (Preliminary note), p. 1186. 



L. E. J. BROUWER: "On linear inner limiting sets", p. 1192. 



J. J VAN Laar: "On the Course of the Values of a and b for Hydrogen at Different Temperatures 

 and Volumes". II. (Communicated by Prof. H. A. LORENTZi, p. 1195. 



76 



Proceedings Royal Acad. Anislerdum. Vol XX. 



