“Shall I fetch the sand back?”
“No, we will use the coarsest emery now; I dare say that will dig out enough. Now then, number one.”
The large-stoppered bottle was fetched from its shelf, and a small portion of the most coarse ground emery taken out with a spatula, spread upon the fixed glass, the speculum carefully laid upon it, and turned a little to spread the material more equally, a few drops of water having been added, and the slow, tedious grinding went on again.
“Hard work, my boy,” said Uncle Richard, as they paused at last from their laborious work, the disc they moved to and fro and round and round, as they slowly changed their positions, being exceedingly heavy.
But Tom, as soon as he got his breath, was too much interested to mind the labour, and after helping 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.