can be fully appreciated. Such a furnace will have passed through it in twenty-four hours the following materials:
|Ore||1,263,360||pounds or||564||gross tons.|
|Atmospheric air (blast)||2,331,840||""||1,041||""|
which is equal to ninety-two tons per hour, or 1·53 tons per minute. From this quantity of materials there will be produced in twenty-four hours 784,000 pounds or 350 gross tons of pig iron, which is at the rate of 32,666 pounds or 14·57 tons per hour, or 544 pounds per minute.
Heating the 25,000 cubic feet of air supplied per minute to a, temperature of 1,200 Fahr., its volume would be increased to 85,000 cubic feet; and, on the supposition that the furnace is blown by seven tuyères, each seven inches in diameter, this torrid air would rush through each tuyère (under a pressure of nine pounds per square inch) at the rate of 12,143 cubic feet, and having the enormous lineal velocity of 45,417 feet per minute. This velocity is over five times that of the most violent tornadoes, and the pressure is more than twenty-five times greater. Should a blast of equal pressure and velocity come from unfathomed space and envelop this earth, it is absolutely certain that no living beings or loose materials would be left upon its rock-ribbed skeleton, which, stripped of its flesh and blood, fields and forests, lakes and oceans, would be hurled into a new orbit and made to assume revolutions and rotations whose amplitude and duration it is impossible to imagine or describe.
[To be continued.]
- Perhaps the volume of materials required in the manufacture of pig iron may be more readily comprehended by considering that, for the making of a pound of that commodity from the best ore, there are required 1·612 pounds of ore; 0·786 pound of coke; 0·451 pound of limestone; 2·977 pounds of air, or a total of 5·876 pounds of materials for each pound of iron produced.