XXVI CONTENTS. 



PAGE 



HuMFBEY, J. C. W. — Macro-etching and Macro-printing 385 



Hanson, D., & J. E. Hubst — Improvements in the Case-hardening Process .. .. 386 

 Andrew, J. H., & G. W, Green — The Manufacture and Working '.of High-speed 



Steel 386 



Arnold, J. O., & F. Ibbotson — The Molecular Constitutions of High-speed Tool 



Steels, and their Correlations with Lathe Efficiencies 386 



NOTICES OF NEW BOOKS. 



Chamberlain, Charles Joseph — The Living Cycads 300 



Gleichen, Alexander — The Theory of Modern Optical Instruments 387 



Strutt, R. J. — Scattering vf Light by Solid Substances 388 



SouTHALL, James P. C. — Mirrors, Prisms and Lenses 388 



Smith, Annie Lorrain — A Monograph of the British Lichens 389 



PROCEEDINGS OF THE SOCIETY. 



Meeting, December 18, 1918 83 



January 15, 1919 84 



„ February 19, 88 



March 19, ,. 187 



Aprilie, „ 191 



May 21, „ 194 



June 18, „ 302 



October 15, ., 391 



November 19, „ 393 



Eepoet of the Microscope Committee of the British Science Guild.. .. 199 



General Index to Volume .. ., 397 



