Charles Krug wrote:

On Sun, 01 May 2005 18:28:29 GMT, Steven and Gail Peterson
wrote:
The recommended method quickly gets into trouble. A swinging pendulum on
a
moving boat, with pitch, roll and yaw accelerations, isn't a reliable
measure of time. See: Longitude : The True Story Lone Genius Who Solved
Greatest Scientific Problem his Time by Dava Sobel.


I thought the Vikings sailed by latitude alone, hoping their food would
last until they got to Nova Scotia (whichever name they called it)

While they didn't have the compass, they did have a Sun compass which would
tell them where North was during the day. it was a sundial used in reverse.

They didn't really sail by latitude becasue they had no angular measurement
instrument to tell them what latitude they were on. The Arabs did (Kamal),
but the Vikings hadn't seen that.


--
Saville

Replicas of 15th-19th century nautical navigational instruments:

http://home.comcast.net/~saville/backstaffhome.html

Restoration of my 82 year old Herreshoff S-Boat sailboat:

http://home.comcast.net/~saville/SBOATrestore.htm

Steambending FAQ with photos:

http://home.comcast.net/~saville/Steambend.htm