Rensselaer Republican, Volume 19, Number 34, Rensselaer, Jasper County, 28 April 1887 — MECHANICAL. [ARTICLE]

MECHANICAL.

At Vienna pipes are made of. paper designed for conveying gas and water under ground. They are rolled’ from sheets like fireworks cases, charged with asphalt during the rolling and lined with an insoluble enamel. They are only half an inch in thickness, and’ yet will resist an internal pressure Of 2,000 pounds. A Munich manufacturer formulates a compound consisting chiefly of common salt, alum., soluble glass, and tungstate of soda, yhich has been introduced with great success in Austria and Switzerland for the extinction of fires, and is now being used in Germany, where the admiralty have recommended it to their navy yards. An improved automatic steam engine of Erie, Pa., make claims to have obtained the same results with a single valve that it has heretofore required from four to six valves to accomplish.' The admission, compression, and release are constant at any and «U points of cut-off from nothing up to threefourths, and beyond if desired. Alexander E. Tucker, writing to Engineering, says that he has successfully edged grooving tools for chill rolls by dipping the actual cutting portion in mercury. No more of the steel than is actually necessary should l>e dipped, as, while imparting extreme hardness, it naturally makes the body of the tool extremely brittle. A steam engine that runs the electriclight system in the works of the Portland, (Me.) Stoneware Company is built on an entirely new principle. It has no piston rod, and is surprisingly compact, the one at the pottery occupying a space 16x19 inches, eighteen inches inheight, yet it does with ease the ordinary work of a ten-horse power engine of the old pattern. The cost of construction is estimated to bo about one-tliird less than that of an ordinary horizontal or upright engine. Sir Joseph Whitworth wa3 the first to , inaugurate a system of standard screw threads. The form of thread, and tlie number of threads per inch which he recommended, were based partly on the results of numerous experiments and partly on the average obtained by comparing the various forms of screwed bolts then in use. The Whitworth system has been very generally adopted in all parts of the civilized world except the United States. The Seller system introduced here in 1864 has the same number of threads per inch, but the form of the thread is different. There are machines now made which employ emery wheels in place of a tool to face off flatirons and other flush surfaces. Flatirons faced off on one of these machines will be fonnd truer than the majority of slide-valve faces as they come from the manufacturers. This result is better obtained by giving the wheel a right-angle movement to the feed motion as it is advancing. A flatiron five inches long and four inches wide can be finished in forty-five seconds, and it will not be so warm but that i,t can be handled. Now a tool which can give such a result in so short a time is a tool of great value, and in these days of close competition it must be taken advantage of. There are results obtained by an emery wheel which cannot be obtained otherwise at any cost.