Mechanical log, comprising a brass rotator with 4 fins that is attached via three jointed brass rods and a universal joint to a register with two fins. The top of the register has a single circular dial divided to 60 with a pointer. On the underside are four more circular dials marked: to 100 (top); to 10; to 6; to 10 (bottom). An inscription beneath these four dials reads, 'Massey LLL Patent / London / 112'.
Patent No 2601 1802
Patent No 7113 1836