A LARGE COMPRESSED-AIR PLANT.
The value of the Louisiana exposition in the promotion of commerce and manufactures is illustrated in one instance by the fact that the two large compressors in Machinery hall, which furnished all compressed air used at the exposition, were both sold before the closing day. The larger one goes to Shaft No. 3 of the Doe Run Lead company, at Central, Mo., and the smaller one to Columbia, Mo., for the air-lift water supply system. The first machine received the only grand prize awarded at the exposition to air-compressors. It has a capacity of 1,300 cubic feet of free air when running at 125 revolutions, and is distinguished by several novel features, the most important of which is the Cincinnati valve-gear, the opening and closing of the admission and the closing of the exhaust being controled mechanically, while the opening of the exhaust is determined by poppet-valves, thus permitting high speed without throttling of the air and wear and rattling of the valves. The smaller machine is fitted with mechanicallj-moved inlet-valves, and is rated at a displacement of 500 cubic feet per minute. Its good workmanship and perfect operation at the Exposition so much impressed the officials of Columbia that they countermanded an order on another manufacturer in order to take this compressor. Both machines were built by tin Laidlaw-Dunn-Gordon company, of 114 Liberty street, Manhattan, New York city.