“Do, uncle, please. Yes, do! The whole top revolves easily enough, and will do so more easily when there are no sails or fan.”

“Do you mean for defence, uncle?” stammered Tom.

“Defence?—nonsense. Attack, boy. The roof will only want modifying, and a long narrow shutter fitting, one that we can open or close easily from within. The place when cleaned, scraped, painted, and coloured will be all that one could wish, and is strong enough to bear anything. We can mount a monster here.”

Tom looked more puzzled than ever. Monster?

“In the floor below make our laboratory, and keep chemicals and plates.”

“Yes, uncle,” said Tom; for he could understand that.

“And on the ground-floor do our grinding and fining.”

“But the millstones are on the floor above,” said Tom.

“Yes, I know, my boy, for the present; but I’ll soon have them lowered down. There, the place will do splendidly, and Mrs Fidler will be at peace.”

Tom did not see how Mrs Fidler could be at peace if the corn was ground on the basement-floor of the mill, but he said nothing.