我们的波士顿信。

我们的波士顿信。

(FROM OUR REGULAR CORRESPONDENT.]

Engine 44, Boston's new fireboat, has, for the last few days been going through crucial tests, to prove the speed steadiness, and capacity upon which her acceptance by the city is conditioned. Last Saturday was devoted to the builder's trial, and a party of nearly a hundred gentlemen and a few ladies participated in her triumph, The specificationt called for four hours steady work by the engines and boilers, and one hour's runniug of the pumps. She demonstrated, sufficiently, her sea going qualities and rode the water as steadily as a Cunarder. Mr. Dexter Brackett, assistant city engineer, was the expert to pass upon the conduct of Iter machinery, and while not entirely satisfied with the results of certain technical tests of iter pumps, he yet considered that they would deliver the full amount of water ealled for. To arrive more nearly at a certainty, however, a second and thoroughly satisfactorytest of the pumps was had on July 24, at the builder's wharf in East Boston. Special interest attached to this test, Inasmuch as this is the first experiment with compound pumps in the fire boat; but they worked to a eharm, showing an astonishingly small amount of jar aud vibration, considering the energy expended. All kinds of tests were applied to prove the water-throwing capacity of the boat. At one time the. twelve hose and three monitor streams were played with picturesque effect at once. Of course they would not all have been effective for tire purposes; hat they demonstrated beyond a peradventure the volume of water that the pumps would deliver, which was considerably in excess of the 4,000 gallons per minute called for by the specifications. Commissioner Iiusscll was exceedingly pleased with the results. It will be several weeks before she goes into commission, the painting and polishing requiring as much time as that. The following is a concise description of the new fireboat. She is 110 feet over all; beam 20 feet; depth of hold, 10 feet; draught, 8 1-2 feet. The engines have vertical, inverted cylinders, thehigh-pressnrecylinderbeing 18 inches and the low-pressure cylinder 30 inches in diameter; and the stroke 24 inches. There are two boilers, and two vertical fly-wheel duplicate fire pumps, double action. In the regular work the pumps will be seen with steam pressure of 95 pounds, the pumping pressure to be 175 pounds. The throwing capacity, on the basis of the contract requirement, means a projection of water equal to 8,640,000 gallons in 24 hours' pumping. The full speed of the boat requires 120 revolutions, with an indicated steam pressure of 110. Her maximum speed on the official trial was 18 knots an hour without pushing. Her pumps, with 175 pounds pressure attained,discharged 0,000 gallons of water per minute during one hour. This was accomplished with the 8 1-4 and 3 1-2 inch nozzles, and powerful streams were thrown from both the two bow towers and the pilot house tower, which were tested singly and combined. Streams were thrown at an estimated distance of 150 to 200 feet, the latter distance being that of the single three inch stream from the pilot house tower.