Bishop, J. Leander (John Leander), 1820-1868 / A history of American manufactures from 1608 to 1860 : exhibiting the origin and growth of the principal mechanic arts and manufactures, from the earliest colonial period to the adoption of the Constitution : and comprising annals of the industry of the United States in machinery, manufactures and useful arts, with a notice of the important inventions, tariffs, and the results of each decennial census
Volume 3 (1868)
Manufactures of Pittsburgh, pp. 96-112
1 ) The O'Hara Glassworks-Jas B. Lyon & Company, Proprietors, Is probably the best representative that could be selected of the many excellent establishments of the same description for which Pittsburgh is famous. Established for nearly a quarter of a century, and enter- prising in originating novel designs, they have accumulated an immense stock of patterns, or metal moulds, some of which have cost two and others three hundred dollars each. The Glassware made here is re- markable for its clearness, smoothness, and purity of color, and the designs are excellently adapted to the material and mode of production. The silex used is a sand of a beautiful quality, found in Berkshire county, Massachusetts, and the minium is manufactured by the firm from pig-lead brought from the State of Illinois. The Glasshouse, an extensive structure, one hundred and fifty by fifty feet, contains three large furnaces, each of which is capable of accommodating ten pots, that hold a batch of three thousand pounds of metal. These pots are all made on the premises, of a clay obtained from Missouri, which is found preferable to the imported. Contiguous to the furnaces are five annealing ovens for tempering the glass after being made; and opposite are four furnaces, known technically as "glory holes," where the glassware is revitrified and polished, by which it obtains that clear, elegant, and gem-like appear- ance that is so desirable and pleasing to the eye. On the ground-floor are also the mill room, for grinding the clay; the pot room, where these huge receptacles are made ; the lead house, where the lead used in making the glass is converted into litharge; a blacksmith shop, and other apartments of more or less importance in the operations of the establishment. Ascending to the second floor, we come first to the pattern shop, where the moulds are designed and prepared, first in wood, then in plaster of Paris, and finally in iron. Adjoining this is the turning and repairing room, which is a miniature machine shop,.provided with lathes and all the requisite tools for repairing, turning, and polishing the interior of the moulds to the smoothness and delicacy of a mirror-the importance of which will be readily understood when we state that any defect in the mould reappears in a blemish in the glass. The grinding and final polishing of the wares are done in the third story, where there are a dozen or more grindstones revolving with immense velocity, and driven by steam power. On the second floor are also the receiving and pack- ing rooms, each forty by seventy-five feet. Here the final operations of inspecting, assorting, and packing the wares of the firm are carried THE O H1ARA OLASSWORKS.
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