The Challenge: Build accurate clocks
Page: 1 2 3 4 5 6 7 8
was the portable clock made?
Making a portable
clock or wrist watch, with no small springs, no battery and no precision
tools ruled out making a mechanical clock, so we opted for a mini-sundial.
To make sure that the sundial wristwatch was accurate, the gnomon had
to point at the correct angle. This meant that the wristwatch had to be
kept level using a plumb line or spirit level. The gnomon also had to
face north so a compass was needed.
Roll up Mike Leahy's
'compact two-piece time-piece': a ridiculous contraption that looked like
a miniature radar station. Amazingly, it worked, and even more incredible is
the fact that during the sixteenth to eighteenth centuries people actually
used to carry portable sundials around, complete with compasses and they're
still made in India! No doubt they looked a little smarter than the Rough
Science creation though!
The producers are not responsible
for the content of external websites.
a sundial from the book on the Web "From Stargazers to Starships"
by David P. Stern on the International Solar-Terrestrial Physics page
on the NASA site
Links about sundials
on The North American Sundial Society site
Sundials on the Internet
- information about all aspects of sundials
about sundials on Jack Aubertís webpage
from Reesís Clocks, Watches and Chronometers, 1819 on Gordon T.
Uberís Home Page
do Clocks Keep Time? on the Physical Science Lessons page on the Reach Out! Michigan website
Theory and Practice by RRJ Rohr, Dover Publications 1996, ISBN 0 4862
Making a Clock-Accurate Sundial Customized to Your Location (for the
Northern Hemisphere) by Sam Muller, Naturegraph Publishers, 1997;
Time by A.
Waugh, Headline 1999; ISBN: 0747221782 Longitude by Dava Sobel, Fourth
Estate 1998 ; ISBN: 1857025717
Longitude by Dava Sobel Fourth Estate, 1999 ; ISBN 1841152331
by E. G. Richards, pub Oxford 1998, ISBN 0 19 286205 7
Albert Waugh, pub Dover 1973, ISBN 0 486 22947 5 Sundials by Christopher
St J. H. Daniel, pub Shire Album 1986, ISBN 0 85263 808 6
Challenges main menu