the stroke. With the two separate sets of automatic machinery required
by engines of the Corliss type, the piston does not always receive its
steam at the beginning of the stroke, and the supply may be cut off
partially or entirely at any point in its passage along the cylinder, as
the work to be done requires. The economic value of such an arrangement
is manifest. No attempt is made here to explain by means of elaborate
diagrams. It is believed that if the reason of things, and the principle
of action, is clear, the particulars may be easily studied by any reader
who is disposed to master mechanical details.




THE AGE OF STEEL


In very recent times the processes of civilization have had a strong and
almost unnoted tendency toward the increased use of the _best_.
Thus, most that iron once was, in use and practice, steel now is. This
use, growing daily, widens the scope that must be taken in discussing
the features of an Age of Steel. One name has largely supplanted the
other. In effect iron has become steel. Had this chapter been written
twenty, or perhaps ten, years earlier, it should have been more
appropriately entitled the Age of Iron. A separation of the two great
metals in general description would be merely technical, and I shall
treat the subject very much as though, in accordance with the practical
facts of the case, the two metals constituted one general subject, one
of them gradually supplanting the other in most of the fields of
industry where iron only was formerly used.