Convert from gry to cable [U.S.]

Unit Definition (gry)
The gry is a proposed unit of distance in the English traditional system. The name was first used in June 1679 by the philosopher John Locke (1632-1704) as a unit equal to 0.001 foot, 0.01 inch, or 0.1 line in a decimalized distance system. (Thomas Jefferson, who was very familiar with Locke's writings, later proposed a similar system in the U.S., but he called 0.001 foot a point rather than a gry.) In 1813, the gry was revived in another decimal measurement scheme in Britain. All these ideas failed, but the gry had some limited use in the nineteenth century as a unit equal to 0.1 line or 1/120 inch (0.211 667 millimeter). Long forgotten, the gry recently came back into the limelight in connection with a puzzle, circulating on the Internet, which asked for three English words ending in -gry. The word "gry" is from the ancient Greek, where it meant "a trifling amount".

Unit Definition (cable [U.S.])
The cable is a unit of distance formerly used at sea. The traditional U.S. cable was equal to 120 fathoms, 720 feet, 0.1185 nautical mile, or about 219.4 meters. The British Admiralty, in 1830, defined the cable to equal exactly 0.1 nautical (Admiralty) mile, which is 608 feet or about 185.3 meters. The cable is also sometimes now defined as a metric cable, which is equal to exactly 200 meters.