Donald Kershaw died on December 21st 2016 at the age of 88 following a brief stay in hospital. He had not been well for some time and suffered from chronic obstructive pulmonary disease. Has mathematical speciality was numerical analysis.
Donald was born in Dewsbury where he attended Wheelwright Grammar School whose alumni, remarkably, also include two other eminent mathematicians: Leslie Fox, who was Professor and founder of the computer laboratory at Oxford, and Tom Kilburn, Professor and head of the School of Computer Science at Manchester. Donald obtained his first degree at University College Hull, his studies being interrupted by travel to Switzerland for treatment for tuberculosis, and a PhD from the University of Edinburgh.
In July 1955 Donald joined Vickers-Armstrong (Aircraft) in Weybridge, where he worked on solving problems relating to aircraft design and operation. His interest in mathematics was sparked by his training as a navigator in the ATC. If the war hadn't ended when it did he said he would have joined the RAF. Donald gives a fascinating account of those early days of computing in the Bulletin of the Computer Conservation Society.
In 1957 Donald moved to the mathematics group of the Admiralty Research Laboratory, headed by Steven Vajda, who later became Professor of Operational Research at Birmingham University. The atmosphere at ARL was more of a research institute and it was there that he was introduced to numerical analysis in which he was later to make his academic reputation with contributions to the theory of QD algorithms, linear algebra, special function theory, approximation theory, splines, quadrature, and integral equations and their applications. It was also there that he published in a laboratory report a solution to an integral equation which was later rediscovered and applied to computerised tomography.
In 1964 Donald joined the Computer Unit at Edinburgh University, which had been set up the previous year by Sidney Michaelson, to lecture in numerical analysis. After establishing a strong publication record he moved in 1971 to a readership at Lancaster University, to strengthen a growing and influential numerical analysis group with professors Charles Clenshaw and Alan Talbot and senior lecturer John Gilbert.
Donald’s academic activities are to be found in the records of numerous meetings he attended at Mathematisches Forschungsinstitut Oberwolfach, the London Mathematical Society Durham Symposia and SERC conferences at Lancaster University. These are liberally sprinkled with the names of many of the contemporary pioneers in the mathematical sciences and Donald's “mathematical descendants”. He is credited with influencing, in his choice of speciality, Will Light, a PhD alumnus and later Senior Lecturer at Lancaster who became professor at Leicester University.
Donald retired from Lancaster University in 1988 but continued with academic research and some lecturing, including teaching at graduate summer schools in Perugia where he enjoyed an enthusiastic reception by the students. Latterly he was guest of honour at the Leslie Fox Prize meeting at Edinburgh in 2013 and may be seen among prize winners in a photograph on the meeting web site.
A singularly able yet modest and unassuming mathematician, Donald was a steadfast friend and will be sadly missed. His love of mathematics dominated, and his rank as Reader at Lancaster University might be compared with a professorship that lacked administrative duties. His hobbies included campanology and woodwork and he had a love of music. He made various musical instruments including an Irish harp, a crumhorn, various dulcimers and flutes and he also made toys for his grandchildren including trucks, a rabbit hutch, a doll house, and a swing. He is survived by his wife Carol, his sons Samuel and Edward, and grandchildren Rebecca, Thomas, James and Harry.