The larger mixer (not pictured) has a capacity of 60 or 80 quarts and is adjacent next to the coppers, where the cooks could easily transfer boiled potatoes to the mixing bowl to make mashed potatoes. The baker used this mixer to mix his nightly run of bread and breakfast pastries.
Here's a description of the mixer from a later mess management specialist rate training manual:
Food-mixing machines are furnished in 20-, 60-, 80-, 110-, and 140-quart sizes with the necessary attachments, paddles, and beaters. The wire whip is used for eggs, cream, and lightweight mixing; the flat beater for cake batters and medium-weight mixing; the dough hook for mixing bread dough; and the wire beater for medium-stiff dough.
One part of the machine revolves through the use of a set of transmissions and differential gears. Various shaped paddles and mixers can be attached to this revolving unit.
The lower part of the mixer contains two extended, adjustable arms. A bowl, containing the foods to be mixed, is placed on these arms and the arms are then moved up so the paddles will revolve throughout the mixture. The machines have either three or four speeds. Usually they have an attachment hub that can be used for a vegetable slicer, juicer, and meat grinder.