Convert from palm [Britain, Roman minor] to cable [British]

Unit Definition (palm [Britain, Roman minor])
A palm, when used as a unit of length, is usually four digits or three inches, i.e. 7.62 cm (for the international inch). The width of an adult human male palm is indeed about 10 centimetres.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (¼ palm), finger (7/24 palm), hand (4/3 palms), shaftment (2 palms), span (3 palms), cubit (6 palms) and ell (15 palms).

Unit Definition (cable [British])
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.