ClipArt ETC
"To measure the depth of; fathom; try or test, as the depth of water and the quality of the ground, by sinking a plummet or lead attached to a line on which is marked the number of fathoms...a, lead; b, counterpoised hooks which engage the loop at the top of the lead; d, wedge-shaped cup for specimens, attached by cord or wire to the pivot of the hooks; e, attachment for the sounding-line or wire. When the cup d touches bottom, the hooks b drop into the position show in E; the sinker or lead then drops over, releasing the cup, and this, with its specimen and the hooks, is drawn to the surface." —Whitney, 1889

British Navy Sounding Apparatus

"To measure the depth of; fathom; try or test, as the depth of water and the quality of the ground,…