Because his method of working was very different from everyone else’s, it is more difficult to make a quantitative comparison, to set the numerical achievement of his work against that of the other great contributors. Perhaps at the end of the project he had actually sent in no more than ten thousand slips, which sounds a fairly modest number. But as virtually all of them proved to be useful, and because every one of them was wanted, and had been ordered, so his achievement as a contributor more than equals the effort achieved by some others in sending ten thousand slips a year.
