Page:The American Cyclopædia (1879) Volume III.djvu/103

 BOKIE BORING 97 carried on with no expense of fuel, and boric acid is obtained to the amount of 5,000,000 Tuscan pounds or more per annum. Since 1854 artificial soffionihave been produced by boring, and the yield from this source is very large. The product is of late years more impure than formerly, the foreign matters having increased from 8 per cent, to 25 per cent., which appears to have excited some apprehension lest the supply may give out. An analysis of the crude acid made by Vohl in 1866 is interesting, as showing the great variety of the associated sub- stances. It is as follows : Boracic acid crystallized 80-000 Hygroscopic water 4-500 Sulphuric acid 9-610 Silicic add 0-810 8and 0-800 Oxide of iron 0-120 Oxide of manganese 0-001 Alomina 0-670 Lime 0-010 Magnesia. 0-600 Potash 0-180 Ammonia 2-980 Soda. 0-002 Chloride of sodium 0-100 Organic matter and loss 0-217 100-000 Our knowledge of the Tuscan locality, and the process as there conducted, is derived from the treatise of Payen, who describes it in detail. Sir John Bowring and Durval have also furnished interesting data concerning it. Boric acid is of value principally for the preparation from it of borax. It is used in manufacturing a paste for artificial gems, and in making enamel. Its price in Tuscany is about 10 cents a pound. BORIE, Pierre Rose Drank Domonlln, a French missionary, born at Beynat, Feb. 20, 1808, put to death in Tonquin, Nov. 24, 1838. After com- pleting his studies for the priesthood, he sailed for Tonquin, Dec. 1, 1831, arriving just at the commencement of a bloody persecution of the Christian converts. He very soon learned to speak the language and accommodate himself to the habits and temper of the Tonquinese, and labored with great zeal and success for six years. In 1838 he was apprehended, severely beaten, and imprisoned, and after four months condemned to be beheaded. He bore his tor- tures with fortitude, and such was the venera- tion of the people for his character that no one was willing to deal the fatal blow. The soldier selected for that purpose intoxicated himself, and performed the task so awkwardly that sev- en strokes were necessary for its completion. After his death the heathens burned gold paper over his grave and honored him as a divinity. BORING, a name common to two distinct me- chanical operations, which bear different ap- pellations in most languages. The one consists in turning the inside surface of cylinders to make them true, the other in cutting holes through solid matter. Cylinders of a diameter smaller than four feet are bored on a lathe ; the cylinder is fastened to the slide-rest, and the tool is keyed on a mandrel or boring bar held between the centres of the lathe ; the cylinder moves lengthwise, and the tool revolves so that the cut is helical. Large cylinders of the thick- ness usual for steam engines are bored on a ver- tical machine, as their weight is sufficient to deflect them when resting on the side. This important tool is of modern invention, and is found only in those large establishments where huge steam engines are built. A boring ma- chine is generally placed in a corner of the shop formed by two solid walls. It consists mainly of a vertical shaft placed below the floors, sup- porting a vertical boring bar which carries a horizontal cutter wheel, and of a strongly rib- bed bed plate on which are four movable stan- dards or supports, with clamps to hold the cyl- inder in a vertical position. The lower end of the shaft rests in a socket on strong founda- tions ; the upper end is keyed loosely to the boring bar, and supports it. The boring bar is guided by two adjustable boxes, the lower one forming a part of the bed plate, the upper one part of an iron beam strongly bolted and brac- ed to the walls. The shaft and boring bar are made to revolve by a train of wheels placed under the floor. The cutter wheel, on which are bolted several tool-carriers, descends slowly along the boring bar. To operate with this machine, the boring bar is at first withdrawn, to make room for the cylinder, which is placed on the standards, and then the bar is put back in its place inside the cylinder. This last is then so adjusted as to have the same axis with the boring bar, and is firmly clamped. Cutting chisels are set on the tool-carriers ; these are adjusted for the depth of cut desired, and the ma- Fia. 1. Boring Machine. chine is put in motion. After the cutter wheel has come down the whole length of the cyl- inder, it is raised by means of a revolving crane