"Well?" he finally ventured.

"What do you make of it?" Firmstone asked.

Luna turned to the assay sheet.

"The average of two hundred assays taken twice a week, twenty-five assays each time, gives twenty-five dollars a ton for the month of May." Luna read the summary.

Firmstone wrote the number on a slip of paper, then took the sheet from the foreman.

"You understand, then, that the ore taken from the mine and sent to the mill in May averaged twenty-five dollars a ton?"

"Yes, that's right." Luna was getting puzzled.

"Very good. You're doing well. Now look at this sheet." Firmstone handed him another paper. "Now read the summary."

Luna read aloud:

"Average loss in tailings, daily samples, May, two dollars and seventy-five cents a ton."