He opened the railing gate, passed through the office, and entered the
laboratory. Firmstone glanced at the foreman, but he met only a stolid
face with no sign of confusion.

"Pan these samples down."

Without a word Luna emptied the sacks into little pans and carefully
washed off the crushed rock, leaving the grains of gold in the pans.
Eight of the pans showed rich in gold, the last two hardly a trace.

Firmstone placed the pans in order.

"What do you make of that?" he asked, sharply.

Luna shook his head.

"That's too much for me."

"What batteries did these two come from?" Firmstone pointed to the two
plates.

"Nine and Ten," the foreman answered, promptly.

"Who works on Nine and Ten?"

"Clancy day and Long night," was the ready answer.

"Did Long work last night?"

"No. He was sick. I told you that, and I asked you if I should put on
Morrison. You didn't say nothing against it."

"Did Nine and Ten run all night?"

"Except for an hour or two, maybe. Nine worked a shoe loose and Ten
burst a screen. That's likely to happen any time. We had to hang up for
that."

"You say you can give no explanation of this?" Firmstone pointed to the
empty pans.

"No, sir."

"Look this over." Firmstone went to his desk in the office and Luna
followed him. He picked up a paper covered with figures marked "Mine
Assays, May," and handed it to the foreman.

Luna glanced over the sheet, then looked inquiringly at Firmstone.

"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."

"You understand from this, do you not, that the gold recovered from the
plates should then be twenty-two dollars and twenty-five cents a ton?"

"Yes, sir." Luna's face was reddening; beads of perspiration were oozing
from his forehead.