How did we guard this bulwark of play? In the chief city of the land, up to half a dozen years ago, the lad had not one place where he might play, safe from the policeman. Not a single playground was there, even on that East-side where half a million tenants were pent up in the big barracks, out of sight and reach of a green spot. Not a school was there with a playground belonging to it. Yes! there was one; over behind the public school in First Street was a little patch in the middle of the block that had once been a graveyard, but had become a mere litter of tin cans and ash-heaps. It took three years and, I think, as many legislative bills to obtain this sorry boon for the living; but, when it was at last made into a playground, the “gang” in that block went out of business. What became of it? Where did it go? To school, probably. That school became the most popular one on the East-side, and the most orderly. For all that, however, this playground long remained the only one. It took years to make us see what a clear-headed man across the sea had made out many years before; namely, that crime in our large cities is, to an unsuspected extent, a question of athletics merely—of giving the boys a chance to play when that is what they need. Boys are like steam boilers with steam always up: the steam has to have a safe outlet, or it will find an unsafe one. Boilers have safety-valves with which it is best not to meddle. The boy’s safety-valve is his play. Let the landlord hang up his sign in the yard that he will have no ball playing there, and let the policeman refuse the lad the chance to play in the street, which is a bad place to play at best—let these two sit on the boy’s safety-valve, and you need not marvel at the explosion you will hear. You can read of it in the papers every day: such and such a “gang” waylaid the policeman on their beat last night and beat him with his own club. It is nothing to marvel at, no special depravity; it was just the boiler that went bang.