iv CONTENTS. 



1920. 1,AGE 



April 12. — General Meeting ... ... ... ... ... 128 



„ L6. — H. Maxwell Lefroy — The Menace of Man's 



Dispersal of Insect Pests ... ... ... 131 



23.— Sib [srael < rOLL a: ncz— Shakespeare's " Shylock " 



and Scott's " Isaac of York " 132 



„ 30.— F. 0. Bower — The Earliest Known Land Flora... 133 



May 1. — Annual Meeting ... ... ... ... ... 147 



3. — General Meeting ... ... ... ... ... 148 



„ 7. — Lord Rayleigh — The Blue Sky and the Optical 



Properties of Air ... ... ... ... ... 152 



„ 14. — Karl Pearson — Sidelights on the Evolution of 



Man 1G0 



„ 21.— J. A. Fleming — The Thermionic Valve in Wire- 

 less Telegraphy and Telephony ... ... ... 161 



„ 28.— W. L. Bragg— Crystal Structure ... 190 



.June 4.— Sir Ronald Ross— Science and Poetry 206 



„ 7. — General Meeting ... ... ... ... ... 228 



July 5. — General Meeting ... ... ... ... ... 231 



Nov. l.— General Meeting 234 



Dec. 6. — General Meeting ... ... ... ... ... 241 



1921. 



1921. 



Jan. 21.— Sib Frank Benson— Shakespeare and Democracy 440 

 „ 28.— Sir James Dewar— Cloudland Studies 412 



