The
boy who struggles with a difficult problem, working hard to apply correctly the rules he has already learned, or to understand those more advanced which may be necessary to complete his work; who turns back after repeated failure to begin again with the knowledge gained from these experiences, and who at last after earnest, careful, steadfast work arrives at the correct solution, has made a scientific demonstration as well as the more fortunate scholar who, with less time and labor, may have reached the same end.
