Page:Collier's New Encyclopedia v. 07.djvu/70

ORDNANCE 40 OBE matter of fact real progress in ordnance has been comparatively modern. In spite of the fact that gunpowder was known to China and the far east for years before it was known in Europe, credit should go to the West for the first use of guns as they are now understood. Little attention was paid to the design of the gun or to the strength of the charge in early days, and the first models were frequently more dangerous to their crews than to the targets. , Early guns were made of wrought or cast iron or bronze, and gradually in- creased in size and weight in order to secure greater strength. They were of course loaded at the muzzle and fired by many devices using springs, air or water have been introduced and many per- fected. In the French 75 millimeter gun, acknowledged the most successful field piece of the World War, its outstanding superior feature was its hydro-pneu- matic recoil mechanism. OBDOVICIAN, a name sometimes given to a geological formation inter- mediate between Cambrian and Silurian ; otherwise accounted the Lower Silurian strata. It is so called from the Ordo- vices, an ancient British tribe. ORDWAY, SAMUEL HANSON, an American lawyer, bom in New York (4^%i^ AMERICAN 4,7 HOWITZER a fuse. The modern gun is made of steel, and only selected parts of special ingots are used. The ingot is cast in the rough form of the gun, bored on a special lathe, then heated and forged on a mandrel, then annealed, then turned and bored to size, tempered and again annealed. The inside of the gun or tube is bored and reamed by a special machine which assures straightness. The outer part or jacket is heated and consequently ex- panded and dropped over the tube, where it cools and shrinks to position. The several parts of the gun are assembled in this fashion. The assembled gun is then^ rifled, turned to final size on the outside, the powder chamber and breech rest are finished, and the gun fitted with a breech lock of either a sliding or in- terrupted screw type. The function of a gun carriage is to support the gun as it is fired, and in the case of mobile guns to furnish a means for transportation. A means for com- pensating the enormous force of recoil has been the subject of much study on the part of designers of ordnance, and City in 1860. Graduated from Brown University in 1880 and took a post-grad- uate course in Harvard. He was ad- mitted to the bar in 1884, and from that time practiced law in New York City. He was a member of many important commissions, including one appointed by Governor Hughes to investigate specula- tion in securities and commodities. Ac- tive in civil service reform work and for years chairman of the executive com- mittee of the Civil Service Reform Association. He wrote many articles and delivered many addresses on civics and economics. ORE, substances found in the earth from which metals are obtained by var- ious processes, but chiefly by roasting and smelting. Ore consists of metals mineralized by chemical combination with one or more of the non-metallic ele- ments. Generally speaking, however, all mineral substances containing metals, combined or free, are called ores. They are found in veins or lodes, in bedded masses, and also disseminated in rocks of all ages, both igneous and stratified