17

O.17

time and attention were devoted to it. Moreover, those problems that at first blush appear utterly insoluble receive, in that very circumstance,—as Edgar Poe remarked in his 'The Murders in the Rue Morgue,'—their smoothly-fitting keys. This particularly adapts them to the Play of Musement.

Forty or fifty minutes of vigorous and unslackened analytic thought bestowed upon one of them usually suffices to educe from it all there is to educe, its general solution. There is no kind of reasoning that I should wish to discourage in