Messrs. Culbertson, McMillen & Co. of Cincinnati, have recently put in successful operation, a new machine, a description of which is given in a Cincinnati paper, as follows:
'A frame of fourteen moulds, one brick to each is drawn by the power of steam between two press rollers, the lower one of which enables the frame to support the pressure of the upper roller, and being run through backwards and forwards equalizes the pressure over the entire face of the brick. These, after undergoing in this mode a pressure of nearly one hundred tons to each brick, a pressure which covers clay, apparently perfectly dry, with a coat of glossy moisture, are raised above the surface of the mould by parallel levers, and are then delivered over to a bench or table by self-acting machinery, whence they are taken in barrows to the stacker at the kiln.
The dry clay is shoveled into a hopper, and if more of the material is pressed into a mould than serves to make a brick, a knife which ranges with the surface of the mould, shaves off the surplus.
Two hands shoveling, two more taking off, and one at the barrow, constitute a gang of five persons who turn out from 30,000 to 35,000 per day of ten hours. As brick makers' days are from sun to sun, say twelve working hours per day, during the season, from 46 to 50,000 bricks, per day, may be made by a single machine. This is, however, by no means the most important feature in the invention.
In the ordinary mode of making bricks, the manufacturer cannot begin operations for the season, until the spring has so far advanced that working in wet clay will no longer chill his moulders' hands. On the same account, he loses also morning hours, until the advance of summer enables his hands to put in the whole period of daylight. He loses, also, sometimes days together--from the entire stoppage of his operations in the rainy weather, which forbids the bricks being put out to dry. In making press brick, all these difficulties are obviated. As a theory, operations in this mode can go on throughout the entire winter, frost never extending into solid clay; but as a practical business, it can be conveniently carried on two months earlier and one month later than in the ordinary mode. Pressed brick, made by these machines, are also stronger than their competitive article, the last of equal hardness in burning, always giving way when struck by the pressed bricks, as I have witnessed. Indeed, it cannot be otherwise, the one being porous and the other as compact as the enormous pressure employed can make it.