Calendar: 1973-1974 Page 455

lxxxii Annual Report of the Delegacy linear theory of plasma waves He attended symposium in Norway on plasma waves and instabilities and presented paper on Cyclotron resonance in an inhomogeneous plasma' Dr Erdos spent the academic year at the University of British Columbia Vancouver and gave lectures at the Universities of Toronto Edmonton and Simon Fraser π Dr Robinson gave seminar and colloquium at the Univer- sity of Newcastle Mathematics Department on 'Black Holes' in December 1971 He gave joint seminar with Muller zum Hagen at the Department of Applied Mathematics and Theoretical Physics at Cambridge University on 'Static Black Holes' in February 1972 He gave talk on 'Static Black Holes' at the Brussels Conference on Relativity in December 1971 He received grant from the Royal Society for travel and subsistence to spend July visiting the International Centre for Theoretical Physics in Trieste Italy Dr Crampin resigned his position as lecturer in the Department to take up an appointment with the Open University and he will be replaced by Dr Davies of the Institute of Theoretical Astron- omy Cambridge Dr Milne gave postgraduate course on the 'Arithmetic of Elliptic Curves' in the University of London He gave short postgraduate course on 'Zcta functions of algebraic varieties' in the University of Nottingham and he addressed the Mathematics Colloquia in the Universities of Cambridge Oxford London and Newcastle Apart from Dr Milne the following people visited the Department during the year Professor Goldhaber for the whole year-University of Maryland and for shorter periods Dr Ε Clark Florida Dr Muller zum Hagen Hamburg Professor Jehne Koln Professor Kasch Munchen Professor Kne- busch Saarbrucken Professor Koch Berlin Dr Lloyd Evans Cambridge Dr Stachel Boston Professor J-P Serre Paris department of physics Number of Students Sc Broad-based 87 Sc Ancillary subject 27 Sc Major subject 70 Postgraduate 23