“Saw brass!” exclaimed Will. “I never saw any such thing done.”

“Did you ever see a watch made?”

“I never did; but”—

“Then, you ought to believe that a watch can’t be made,” interposed the machinist.

“It looks absurd to me to talk of sawing brass, and I don’t believe it can be done,” persisted Will.

“Possibly I may be able to convince you that it can be done: in fact, I know I can, if you are not very unreasonable,” added Mr. Jepson, as he put the bar of brass into one of his iron vises, and screwed it up tight. “Now, stand by me, and see that I don’t deceive you.”

The machinist took a hack-saw from a hook in front of him.

“There is the brass in the vise, and here is the saw,” continued the instructor. “I shall saw the brass bar into two pieces, and I shall do it about as quick as an amateur would saw a piece of hard wood of the same size.”

“That thing don’t look like a saw,” Will objected.

The instructor took from a drawer a package of hack-saws, on which there was a label.