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Lab Animal Feeder


The portion of the apparatus, deemed the “front”, consists of two pieces of flat metal that have been attached. These plates will be referred to as the “front left plate” and the “front right plate.” The “front left plate” is mostly covered by a large metal gear with small teeth on the outside and small holes that form a circle around the inside edge of the gear. In the middle of the gear, there is a round knob with a black plastic head that is screwed on to the gear. A label has been attached to the knob with a string, which reads “BISHOP.” On the part of the knob that has been screwed to the gear someone has written the word “LEFT” in red. On the top right corner of the “front left plate” a University of Toronto label has been screwed down. On the bottom left of the “front left plate” a manufacturing label has been screwed to it. To the right of this label are four more screws and a much smaller corroded metal gear that fits into the larger gear. This small gear is attached to a rectangular piece of metal that protrudes outward.

The “front right plate” is similar but is missing the large gear. However, there are machine made holes and scratch marks that indicate that a similar gear was once attached to it. This side also has a manufacturing label screwed to the bottom left corner and a smaller gear on the right corner with a rectangular piece of metal that protrudes outward. The other main difference is that this side has 7 discolored screws.

The portion of the apparatus, deemed the “back”, will again be referred to in terms of the “back left plate” and the “back right plate.” On the top of “back left plate” there is a protruding metal rectangle. This rectangle has three holes in it. The largest hole is open, and inside is a small light bulb. On either side of this hole, there are two smaller holes, which connect to plastic tubing. These tubes connect to a small rectangle screwed into the plate on each side. From the light bulb section four wires protrude. The largest two are black, and the two smaller ones are green and white. Each black wire connects to two brown plastic pieces with a label reading “USE ASTATIC NEEDLE N4-3” on each. The green and white wires connect to the light. These wires then connect to a small black box on the left side of the apparatus. From this box run two black wires and two purple wires. These wires connect to rounded rectangular protruding boxes on the bottom left of each plate. One black and purple wire connects to the left side of each box. Additionally, each plate has a rounded cylinder protruding from its center, which has been screwed in where the knob is located on the front. Below these cylinders is a metal bar that is most likely holding the two plates together. There are two small holes located on the bottom edge of each plate that have residue around them as if they were both once connected to something else. The right edge of the “back right plate” has a long metal rod protruding from its center.

Accession Number: 2014.psy.152

Alternative Name: Unknown

Primary Materials:

Aluminum alloy, other various metals, plastic tubing, coated wiring, a light bulb, plastics, and tape


Two manufacturer’s labels on the front of the apparatus read, “Manufactured by Ralph Gerbrands, 96 Ronald Road, Arlington, MASS”. There is also a University of Toronto label on the front that reads, “Department of Psychology Research Equipment No. 395 FP 71, University of Toronto”. On the base part of the knob on the front the word “LEFT” has been written and an old label tied to this knob reads “BISHOP.” A metal bar on the back of the apparatus reads 70T6 ALLOY 6061. On the back of the apparatus, the lower right rounded rectangular metal object to which the black and purple wires connect reads 116 VOC and 748. The yellow material the wires connect to on the back this metal object reads VMFP. The two brown plastic parts on the back of the apparatus by the plastic tubing and the light bulb have labels reading “USE ASTATIC NEEDLE N4-3.”

Dimensions (cm):

Height = 24, Width = 32.5, Length = 38.5


Based on the type of lab equipment Ralph Gerbrands manufactured, it is possible this is an operant conditioning animal feeder. Operant conditioning is a method which teaches animals to learn through behavioral rewards and punishments.


Overall, the apparatus is in fair physical condition. The majority of the condition issues include slight corrosion on some metal parts, yellowed plastic tubing, slight scratches that were sustained from use, and adhesive residue. It is important to note that this apparatus is incomplete and has many parts missing making it hard to determine the original function of the object. Additionally, the apparatus is both dusty and dirty.

Associated Instruments: 2011.psy.26


Ralph Gerbrands Company, 96 Ronald Road Arlington, Massachusetts

Date of Manufacture: mid 20th-century


Department of Psychology, University of Toronto.

Additional Information and References:

The date of manufacture is based on the address of the manufacturer and ads in Journal of the Experimental Analysis of Behavior.

Historical Notes:

Ralph Gerbrands was born in 1905 and began making psychological equipment in 1929 for the Department of Psychology at Harvard. The following year, Gerbrands received permission to create custom-designed apparatuses for other laboratories. He soon went into business for himself and founded the Ralph Gerbrands Company, which became a major supplier of experimental psychology equipment, mostly used for operant conditioning. He expanded his business in 1940, when he set up a shop in his home and began publishing a catalogue. About 1954, he began working in a rented shop space on Warren Street and later moved to a plant on Beck Road in 1967. His most well known product is the cumulative recorder. He advertised his products in the Journal of the Experimental Analysis of Behavior for 37 years from the time the journal started in 1958 until 1994. Gerbrands retired in 1973. The Gerbrands Corporation, formerly the Ralph Gerbrands Company, closed in September 1994.

This information is based on the following sources:

1994. “A Farewell to Gerbrands.” Journal of the Experimental Analysis of Behavior 62: 445.

Dinsmoor, Kay. 1987. “A Special Tribute to Ralph Gerbrands.” Journal of the Experimental Analysis of Behavior 48: 513-514.