Logboard

1659, Navigation by the Mariners Plain Scale New Plain'd, by John Collins Every Noon the Master and his Mates take the reckoning off the Log-board, and double the Knots run, and then divide the Product, which is the number of Miles run by three, the quotient is the Leagues run since the former Noon, and according to custom the Log is thrown every two hours, and I never knew the course nearer expressed on the Log-board, then to half a point of the Compass.