Thus wrote John Wallis, Wren's fellow mathematical professor at Oxford, of his own introduction to mathematics at Cambridge around 1635. We can understand why the young Wallis, his undergraduate studies devoted to what was a mediaeval curriculum, should, by comparison, have seen contemporary mathematics as practical rather than academic – the province of merchants, navigators and surveyors. For there was, in England, a vigorous tradition of practical mathematics, linking mathematicians and mathematical teachers with the practitioners of the mathematical sciences – instrument-makers and their clients. While there was a sustained interest in theoretical developments, and here in time the University men would play an important role, this interest was an integral part of a subject whose overall character we would recognize as ‘applied’. The exploitation of mathematics to practical ends, particularly in the use of mathematical instruments, was a dominant force, and its focus was, appropriately, in London. Wren himself, in 1657, said that: