I forgot to say , note the fusee compensator cone on the axis of the
lower pulley. This takes/supplies the perforated tape, winding around
that pulley. The fusee offesetting the varying weight of the suspension
band. Also the large float about 2ft 6 in diameter is shown on the
floor. The suspension must cope with the possibility of that float
puncturing, filling with water, and jamming unsupported by seawater.
Other models of the same make used a simple wire suspension and
returning the counterweight down the sampling well, which then
transfered silt and slime onot the recorder, not the case with the type
pictured.
2 inches on the traverse represents 2 foot of water level change, 1 in
to 1 foot scaling in the gear train.