"And last," he says. "We found this by the stove." He
lifts out a heavy brass bowl with calibration marks around the lip. From
inside the bowl he lifts out a heavy metal disk. "Some sort of pointing
"It's the Bath Compass," Claudia says immediately. "Captain
Torvey described it in an old letter I have. He was convinced it pointed
north more accurately than any other compass. I can tell
the full story, if you want."
"How does it work, do you know?"
She takes the device from William. "You fill the bowl
with mercury," she says, "up to this line. Then you float the disk in
it. When you're done, you use this spout to pour the mercury back."
"Into what?" William reaches down. "Into one of these,
eh?" he says, pulling one out one of the thick glass bottles. It's full
of shining silver liquid. "We found two of them next to the device, still
full of quicksilver. Heavy, aren't they?"
An Access Excellence
Science Mystery sponsored by Genentech, Inc.
Copyright © 1997 Genentech, Inc.; all rights reserved.