Made by Thomas Walker, this depth sounder was the type made for larger, commercial vessels. The spinner is inscribed with an anchor and the initials T.W. and includes the original whipped line for attaching a lead line. Although it would appear to place the device upside down the whipped line attached to this example is apparently the lead for the lowering/hoisting line. The sounding weight would attach to the opposite eye.
This Walker patent improvement over the earlier Massey system incorporates a locking level to prevent the spinner from rotating as it descends. Contact with the bottom releases the locking lever and the depth is recorded on two calibrated dials as the device is hauled in. One dial is calibrated from 10-30 fathoms and the second is an integrated meter that records from 30-150 fathoms requiring five times as many revolutions of the spinner as the first dial.
Signed T. Walker, Patent 6821K with Anchor.
