Although Pell had nothing to do with the solution, posterity has termed the equation Pell's Equation, or Problem, when more rightly it should be the Hindu Problem, in recognition of the mathematical attainments of the Brahmans.
Chamberlain, the necessity of committing to memory two syllabaries, one of which has many variant forms, and at least two or three thousand Chinese ideographs, in forms standard and cursive ideographs, too, most of which are susceptible of three or four different readings according to circuinstance,add, further, that all these kinds of written symbols are apt to be encountered pell mell on the same page, and the task of mastering Japanese becomes almost Herculean.
Many of Pell's manuscripts fell into the hands of Dr Busby, master of Westminster School, and afterwards came into the possession of the Royal Society; they are still preserved in something like forty folio volumes, which contain, not only Pell's own memoirs, but much of his correspondence with the mathematicians of his time.
Our older boys will demonstrate their daily training at the pell using a broadsword.
Thus or otherwise he had become sufficiently known by 1645 to be chosen as a referee, with Descartes, Roberval and others, in the famous controversy between John Pell and the Dane Longomontanus over that problem of the squaring of the circle which was seen later on to have such a fatal charm for himself.