Unique Floating Log and Current Meter – Edward Massey, London, ca. 1850
This very rare instrument in original chest, designed by Edw. Massey is for messuring the speeds of tides or curents. It can also be used in boat surveys for messuring lakes. It consists of a cigar-shaped brass float and registering wheelwork with a very light rotator which will revolve in the slowest currents. When in use the instrument should be secured to a stationary boat or buoy or to a pole driven into the bed of the stream. Before taking the readings in rapid streams it is important to see that the instrument is balanced to float horizontally and tendency in the float to rise at either end should be corrected by sliding the register underneath. The measurement begins and ends with the operation of two strings attached to the small handle on the front of the clockwork. The registration is shewn on five dials, the three to the left giving the current in nautical miles and parts thereof. The remaining two shewing the current in feet. With the two associated lines, the mechanism can be switched on and off from the boat.
The arrangement with a standard on the chest suggests that this has been a demonstration model. Manufactured by Stanley London. No space has been reserved for the standard in the box. The standard is packed in wax paper and lays loose in the chest.
Another one, without chest and standard, is described in Sharp’s Distance Run (see cat.nr BK.1-14), p 139, manufactured by T. Walker & Son.
Date: ca. 1850
HWL chest: 9,5x66x19 cm (3.8x26x7.5 in)
LD Log: 66×6,5 cm (26×2.5 in)
Signed: Stanley London