He looked at the figures again--more carefully.
The truth was that until that evening he had never given much attention to those figures: it was the word Wilchester that had fascinated him.
But now, summoning all his by no means small arithmetical knowledge to his aid, Stoner concentrated himself on an effort to discover what those figures meant.

That they were a calculation of some sort he had always known--now he wanted to know of what.
The solution of the problem came to him all of a sudden--as the solution of arithmetical problems often does come.

He saw the whole thing quite plainly and wondered that he had not seen it at a first glance.

The figures represented nothing whatever but three plain and common sums--in compound arithmetic.

Cotherstone, for some reason of his own, had taken the sum of two thousand pounds as a foundation, and had calculated (1st) what thirty years' interest on that sum at three and a half per cent.
would come to; and (2nd) what thirty years' interest at five per cent.
would come to; and (3rd) what the compound interest on two thousand pounds would come to--capital and compound interest--in the same period.
The last reckoning--the compound interest one--had been crossed over and out with vigorous dashes of the pen, as if the calculator had been appalled on discovering what an original sum of two thousand pounds, left at compound interest for thirty years, would be transformed into in that time.
All this was so much Greek to Stoner.