ClipArt ETC
"The falling weights EE turned a paddle-wheel stirrer inside the cylindrical vessel G, which was filled with water and was much like the common ice-cream freezer. The friction of the stirrer heated the water; and when distance was measured through which the weights fell, it was possible to calculate the relation between the work done by the falling weights and the heat developed in the water." Louis Derr, 1911

Thermodynamics Apparatus Showing the Relationship between the First and Second Principals

"The falling weights EE turned a paddle-wheel stirrer inside the cylindrical vessel G, which was filled…