arnock, who went to open the
door.

Kerr came in and after a time began to talk about the fastenings for the
main tie-beam.

"As the rock is sound and can be thawed, I think we could use a bolt on
the Lewis plan. Give me some paper and I'll make a sketch you can take
to the smith."

Charnock examined the drawing and noted that the holding part of the
bolt was shaped like the letter Y, except that the stalk was split.
A wedge was sketched to fit the split, and would obviously expand the
upper arms to fit tightly into a fan-shaped hole with a narrow mouth.

"I've not seen this kind of fastening before," he said. "It ought to
grip well, but something depends upon the wedge."

Kerr nodded. "The wedge must be properly forged and fit tight, but
there's a cross bolt to stop it backing out. So long as it doesn't break
under the hammer, it can't come loose. Something depends on the way the
hole is cut and the rock, but the stuff you're working is hard enough."

Next morning Charnock took the drawing to the smith, and calling at
the forge a day or two later, found Wilkinson sitting on a box. He had
brought a pick to be mended and made a few ironical remarks, until the
smith showed Charnock some irons he had forged.

"I guess that's what you want, but I haven't finished the Lewis yet.
Reckoned I'd wait until I could get a bit of horseshoe iron for the
wedge when the new stores come along."

"What's that bar in the corner?" Charnock asked.

"Steel," said the smith. "A bit off the end would make a wedge, but you
want to be careful you don't overheat the steel in the forge if it's to
stand hammering after. Horseshoe iron's better for your particular job.
Come back in a day or two and I'll have the thing ready."

Charnock left him and one afternoon soon afterwards helped Festing to
notch and bore the heavy cross-tie to fit the post and the ends of the
timbers it was to hold in place. These were intended to strengthen the
frame, of which the post and tie were the most important members, and
Festing had waited until their other ends were securely fixed. When the
light was fading he beckoned Charnock.

"You might get the Lewis bolt. The smith sent word it's ready and I want
to fasten the tie before we stop."

When Charnock reached the forge the smith was absent, but he blew the
fire until the light flickered about the shop and looked for the
bolt. He found it in a corner and took the wedge to the hearth. It was
properly sh