ping to lift one disc from the other, he looked
on eagerly at his uncle's busy fingers, as he carefully sponged and
cleaned both glasses.

"See how the coarse emery we began with has become ground down."

"Yes, into a slime," said Tom.

"Partly glass," said Uncle Richard, as he drew attention now to the face
of the speculum, which was scratched more deeply already, and displayed
a different grain.

Fresh emery out of the bottle was applied, moistened a little more, and
the grinding went on for a while. Then there was a fresh washing, more
of the coarse emery applied, and so the task went on hour after hour
that day and the next, when in the afternoon when the zinc mould was
applied to the surface it fitted in almost exactly, and Tom gave a
cheer.

"Yes, that will do," said Uncle Richard, whose face glowed with the
exertion.

"What next then?" said Tom eagerly.

"The next grade of emery, boy," was the reply; "our task is of course
now not to grind the speculum deeply, but to grind out all these
scratches till it is as limpid as the surface of pure water."

"Don't look possible," said Tom. "Well, we will try."

The next morning they worked for an hour before breakfast in precisely
the same way, gave a couple of hours to the task after breakfast, two
more in the afternoon, and one in the evening--"a regular
muscle-softener," Uncle Richard called it; but when for the last time
the finely-ground emery number two was washed off, and the speculum
examined, its surface looked much better, the rougher scratchings having
disappeared.

Tom was all eagerness to begin the next day, when the number three emery
was tried in precisely the same way. Then came work with the number
four, very little of which was used at a time; and when this was put
aside for number five, Tom again cheered, for the concave surface had
become beautifully fine.

"Two more workings, and then the finishing," said Uncle Richard. "Think
we shall polish out all the scratchings?"

"Why, they are gone now," cried Tom.

"Yes, it shows what patience will do," said Uncle Richard; "a man can't
lift a house all at once, but he could do it a brick at a time."

The speculum was carefully placed aside after its cleansing, and the
pair of amateur opticians locked up the place after hanging up their
aprons.

"Wouldn't do to break that now, Tom, my boy."

"Break it?" cried the boy; "oh, it would be horrible. Why, we should
have to make another, and