The author is a Professor in the Department of Mathematical and Computer Sciences, Colorado School of Mines, USA. Before moving there in 1999, he was a Reader in the Department of Mathematics, University of Manchester. He has been an Executive Editor of the Quarterly Journal of Mechanics and Applied Mathematics for 15 years. He is an Associate Editor of the SIAM Journal on Applied Mathematics and of the Journal of Integral Equations and Applications, and he is a member of the Editorial Board of the Proceedings of the Royal Society A. He has published about 100 papers in refereed journals and o...