THE foul water from the water main on One Hundred and Thirty-eighth street and Amsterdam avenue is said to be occasioned by a “dead end.” It has caused sickness of a serious character and death among the children of the Hebrew Orphan asylum. It is suggested that the water be circulated by the “ blowing off ” process, and, better still, by connecting with some other main to insure the certainty of constant circulation. The best of water will foul in a water pipe, if not kept in circulation; how much more needful, then, is circulation in water mains which furnish indifferent water—water, in fact, so fully charged with organic matter that, on the slightest error of engineering and mechanical judgment concerning its distribution, asserts its mal-odorous properties in unmistakable evidence —and to the supreme disgust of its users. How long will the inhabitants of the City of New York tolerate this state of things? Will its water-users content themselves by submitting to apologies and excuses, rather than insist that new sources of water supply fit to drink shall be provided ? The board of health, we hope, will pursue its duty and, acting with the highest degree of efficiency and fearlessness, and aid in determining substantial and permanent beneficial results.