As he spoke the future speculum was carefully lifted off the lower one, sponged with clean water, and on examination proved to be pretty well scratched in the middle in a round patch, but the marks grew less and less, till at the edge of the glass it was hardly scratched at all.
“There, you see where we bite hardest,” said Uncle Richard; “now we’ll give it a rest, and ourselves too.”
“But we shall never get done like this,” cried Tom.
“Oh yes, we shall, boy; and I’m not going to leave off our work. Let’s see: this we must call the workshop, the floor above our laboratory, and the top of course the observatory. Now then, let’s go up into our laboratory, and I’ll give you a lesson in elutriation.”
Chapter Thirteen.
“I haven’t got a dictionary here, uncle,” said Tom, with a smile, as they stood at the massive table under the window in the laboratory. “I don’t know what elutriation means.”
“I dare say not. I didn’t till I was nearly fifty, Tom, but you soon shall know. Fetch that tin off the shelf.”
Tom obeyed, and found a label on the top, on which was printed “Best Ground Emery.”