elder Siured energetically working the machine by which he finishes the soles for sandals. He thus maintains the vigorous health that has enabled him, for so many years, to devote some ten hours a day to science.
"The machine that so interested you is his special hobby and relaxation. The important improvements due to him have rendered that machine about as perfect in one way as can be desired. But he has set his heart on rendering the machine capable of solving completely the converse as well as the direct problem."
"What is that?" inquired I.
"At present the machine solves perfectly the direct problem,—Given a function, to describe its curve. He wishes to adapt it to the solution of the converse problem,—Given any plane curve, to write down its function."
"That seems to me difficult, if not impossible," said I dubiously.
"The simpler cases are already mastered, however," was the reply; "and he expresses great hopes in regard to the rest."
"But these pursuits of his must involve considerable expense," said I, remembering the comparatively small capital that each could inherit.
"All expenses are probably covered by the small contribution received from every educational institution throughout the world that makes use of his inventions. In return, he gives a full right to all improvements as he reports them. More than this he does not desire."
"You have, then, such things as patent rights among you," I remarked.
