NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Traverse board and the log.
From: Renee Mattie
Date: 2005 Dec 2, 19:11 -0500
From: Renee Mattie
Date: 2005 Dec 2, 19:11 -0500
Here is an example of a traverse board that looks like Duane Cline's drawing: http://www.mariner.org/educationalad/ageofex/images/traverse.jpg on http://www.mariner.org/educationalad/ageofex/navmethods.php You can see that the keeper pin for the speed pegs is in the middle of the speed peg holes. Here is an example of a traverse board that might be used according to the description given by Duane Cline on the same web page: http://home.comcast.net/~saville/traverse_board.htm http://home.comcast.net/~saville/tboard1640.jpg The first image is of a "replica of an Italian Traverse Board made in the 1640's". It shows 8 rows of 10 peg-holes. Four rows are on the left, four on the right. There are no "peg keepers" (though there is an empty hole that might do for a "peg belaying pin" in the center of the compass rose), and the pegs seem to be inserted randomly. On the same page, the second image is of a traverse board with an awful lot of speed-peg holes. The traverse board was "made for the Salem "Friendship": a replica of a 1797 merchant vessel out of Salem, Massachusetts" http://home.comcast.net/~saville/Straverse.jpg There are two columns of speed holes. Each column has 8 rows of 10 peg-holes -- 9 in a staggered line, plus one more (home?) peg-hole set apart from the others. The explanation of these holes from the proprietor of Backstaff Instruments (Gregg Germain?) is: "Each 4 hour watch was broken up into 8, 30 minute segments. At the start of a new watch, the log was hove. The measured speed was indicated in knots and eigths of a knot by placing pegs in the first two rows of holes at the bottom of the traverse board. The first row denoted knots; the second eigths of a knot. There are eight sets of two rows of holes at the bottom of the Traverse Board: one set per 30 minute "glass" of the watch." He does not indicate what he used for a model, or where he got the information on how it was used. It would seem that the right-hand column has more than enough holes for recording eighths. Speeds up to 9 + 9/8 (10 1/8) knots could have been recorded. But that sounds like a confusing way to do it. A traverse board was supposed to reduce navigational errors by making it easy to record sailings every glass. Would eighths of a knot really have been recorded in the 1790s? Again, there is a hole for a "peg belaying pin" in the center of the compass rose, but no pin, no strings, and no pegs. Renee Mattie