TERRA-COTTA, BRICK, ETC.
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in their report upon pottery at the Exhibition of 1851, give a very full list of works, publications, and patents connected with brick-making machinery. ^ Those specially interested in this branch of the subject may find in the above-cited authorities the most accurate available information, at least from the European point of view.*
Hoffmann’s Furnace.
The great establishment for the manufacture of bricks in Vienna now has thirty-three of Hoffmann’s patent " ring- ovens” or annular brick-kilns in use. They are said to mark a new era in the history of the works, effecting a great saving of fuel, and consequently increasing the profits. They are equally applicable to burning brick, lime, earthenware, cement, and gypsum. The inventor states that over one thousand are now in use, and claims to effect a saving of two-thirds of the fuel required by the old methods of burning. Inasmuch as a very good description of the apparatus has been given by Dr. Barnard in his report on the Paris Exposition,f it is sufficient to direct attention to this furnace, which does not appear to have found favor in the United States. One objection given against its use is the greater scale upon which our brick manufacture is conducted. When a kiln of the ordinary form is opened there is room enough for carts and horses to drive in and load with brick of any desired kind,—either hard- burned, pressed, or soft, or " salmon brick.” This objection might, however, be readily overcome by making the chambers of greater size.
Clay Pifes.
The manufacture of clay pipes is a branch of ceramic art of no small importance, industrially. The establishment of Messrs. McKlroy & Co., in Philadelphia, turns out about a thousand gross of pipes weekly. About twenty different styles are made, ranging in price from 85 cents to $1.35 the gross. A clay of peculiar excellence is required.
* Pottery—Terra-Cotta Stoneware, Fire-Brick, etc. Van Nostrand, 1872. t Industrial Arts, by Frederick A. P. Barnard, LL. D.