“That was ever so long ago, William,” she said. “You’ve not been attending.”

William cleared his throat with a certain dignity and made no answer.

“Tell him, Henry.”

Henry ceased his enthralling occupation of trying to push a fly into his ink-well with his nib and answered mechanically:

“Two negatives make an affirmative.”

“Yes. Say that, William.”

William repeated it without betraying any great interest in the fact.

“Yes. What’s a negative, William?”

William sighed.

“Somethin’ about photographs?” he said obligingly.