gra,—"Fifteen knots an hour " is clear English. It conveys the fact that a ship can pass through or over fifteen nautical miles of sea in one hour. Mr. J. Burroughs' letter is learned enough, but it is neither clear nor le Informative, My Ency. Brit. is silent and my O.E.D. is obscure about the maritime "knot."
I have used the " hand log" hundreds of times. The rough-and-ready CM apparatus was a wooden reel with 150 fathoms of thin line, on the end which was the " log ship," a sector of wood weighted to make it float se ertically until a strain on the line pulled out a peg and thus allowed t to be hauled in easily. Ninety feet from the "log ship" the line was re arked with white bunting, and this length was called the " stray line " 0 carry the "log ship" clear of eddies. Forty-seven feet three inches m the bunting was a "knot " on the line, and then a "knot" for
every length of 47 ft. 3 in. A twenty-eight-second sand-glass completed the outfit.
The "log ship " was dropped overboard and the line ran or was helped from the reel held over his head by one of the "reelers." As the bunting passed over the stern rail, the man in charge called " turn " to the " reeler " with the sand-glass, the line continued to run out without slack or strain ; the " sand-glass " man said " stand by," and then " stop "; when the line was instantly checked and the nearest "knot " noted.
It will be seen that the computations are inexact and there are variables such as the sand-glass, the moisture in the line and many others. Hence the expression " near enough for a sailing ship."
Trims was provided a record of the " knots " covered in twenty-eight seconds and their relation to nautical miles in one hour. The nautical mile is 6,o81 feet. To " heave the log " for speeds over eight knots is difficult. I was knocked out when a " reeler " let go the heavy reel while I was trying to pull off 200 yards of line in twenty-eight seconds ; say a good twelve knots.
All modern ships are fitted with " cherub " or other speed and distance meter type logs marked in nautical miles or "knots ": why not?
I am less certain of my grammar than of my facts.—Yours faithfully,