In the following Journal it is to be remembered that the Winds are by true Compass, the Dutch always having a moveable center Card which they set to true North and South as often as they discover the Variation to alter 2½ Degrees.
In every Watch also the Officer corrects the Course for lee way so that it is not to be supposed I have any judgement in finding my Long'd by Account.
They heave no Log, as such they say is not allowed by the Company. Their manner of computing their distance is thus— They have a distance of 40 feet measured along the Ship side from Aft forward, and laying over at the after part they take notice of the first remarkable patch of froth that is made opposite to the other extremity of the measured distance, they then count half seconds untill the mark of froth is abreast of them, with which number they divide 48 and it gives them the Dutch miles the Ship runs in 4 Hours, or the English miles in one hour. Example suppose they count 6, the sixes in 48 is 8 times which is 8 English Miles an hour; but I cannot learn from what principal it is founded on.
If we followed a similar plan of looking at the Sea we should mark a distance on the Ships side of 50 feet and count seconds, then 30 divided by the number counted would give the distance the Ship runs pr. Hour; but happily we have adopted a Log and Line which is the most exact at measuring distances at Sea for general use and by it the greatest error in long Voyages is not more than 3 Degrees, while we know the Dutch to be frequently out 10 Degrees.