A MODEL FIRE RISK.
The Boston store at Providence, R. I., is looked upon by insurance men as a most perfectly secured fire risk. Automatic sprinklers cover every room, closet, stairway, and elevator shaft in the entire building. The water supply for the sprinklers is taken from two six-inch connections with the city mains, which gives a pressure of about seventy pounds at the curb. A second supply is obtained from an elevated tank of 10,000 gallons capacity, located fifteen feet above the highest sprinklers. As the new addition to the store on Fulton street necessitated a third source of supply, and it was also desirable to increase the pressure on the systems so that the sprinklers should be made more effective, it was decided to place on the roof two steel pressure-tanks, with a capacity of 6,000 gallons each. All of these supplies connect with a general tieup pipe, so that, should sprinklers open in any part of the building, they would have the advantage of all three sources of supply. The cylindrical pres sure-tanks are six feet in diameter and thirty feet long; they are set horizontally; and are filled two thirds full of water. An air-pressure of seventy-five pounds pumped in over the water gives over fifteen pounds pressure on the highest line of sprinklers, when all the water has been discharged from the tank. Should the system open, there would im mediately be a large volume of water at highpressure to supply the sprinkler system. When the pressure-tank is exhausted or the pressure reduced to the pressure of the city, or gravity-tank, then these sources of supply will be brought into action, and will deliver water to the heads. This pressure tank equipment is one of the largest ever installed, and weighs when completed and filled with water, about fifty-five tons, in addition to the automatic sprinklers inside the building, there is a system of open sprinklers under the cornice on all sides of the risk. These are turned on by hand, and form a water curtain which is an effective protection against fire in an exposing building. Another interesting feature in the new addition is the use of windows in which glass, with wire netting imbedded in it. is used. The glass is set in metal frames, and forms an effective fire-stop.