A gentleman direct from Baltimore, and who has seen the steam-gun (about which considerable has been said) operate, has furnished us with the following description of it:  

It is on four wheels; the boiler is like that of an ordinary steam fire engine, the cylinder being upright. There is but one barrel, which is of steel, on a pivot, and otherwise is like an ordinary musket barrel. It is fed or loaded through a hopper entering the barrel directly over the pivot. The barrel has a rotary motion, and performs the circumference, by machinery attached, at the rate of about sixteen hundred times a minute. The balls are let into the barrel through a valve at will, and every time the barrel comes round to a certain point, another valve, self-operated, lets out a ball, which is propelled solely by the velocity of the barrel in revolving.