Egg Scale

Reliable Egg Scales

San Lorenzo Valley Museum Collection

These are early 1900s examples of egg scales made by the Reliable Manufacturing Company, Los Angeles, California. 

 
The minimum weight for a specific sized egg varied over time. At one point the weight of a medium egg was 1-7/12 oz (19 oz per dozen) and for a large egg it was 1-5/6 oz (22 oz per dozen).

Note: Modern USA egg sizes are 1-3/4 oz

for a medium egg and 2 oz for a large egg.



San Lorenzo Valley Museum Collection

"Speed, accuracy and endurance are built into every feature of this scale. The shift weight can be reversed to weight [sic] pullets or extras merely by the flip of a finger. Steel bearings, finely grounds [sic] to a knife edge, eliminate friction and insure [sic] rapid operation. Notched board base fits across top of egg case to facilitate packing."


The original cost of the scale was $2.90.

The eggs were graded using a combination of a flip weight on the beam and loose weights, usually two,  that hung on a notch in the beam  - the hook weight - or sat on the egg cradle -  the ring weight.

 

Hook Weight
San Lorenzo Valley Museum Collection

The Reliable Egg Scale
San Lorenzo Valley Museum Collection

Here is a transcript of a copy of one of the sets of instructions:

DIRECTIONS FOR OPERATING RELIABLE EGG SCALE

1 – Set scale level. 2 – Do not use oil in bearings. 3 – Handle carefully, keep clean. 4 – When egg lowers cup half way it is one of the following grades:

    

	FLIP WEIGHT	HOOK WEIGHT	RING WEIGHT
Small	Toward Cup	None	ON CUP
Medium	Toward Cup	None	None
Large	Away From Cup	None	None
Extra Large	Toward Cup	Large Wt. On	None
Jumbo	Away From Cup	Large Wt. On	None

Our scales are set for minimum weight requirements. If one ounce heavier eggs are desired, use small hook weight.

SIZE SPECIFICATIONS

“Jumbo”: ... Uniform in size: not less than 2-5/12 oz. each and 30 oz. per doz.

“Extra Large”: ... Uniform in size: not less than 2-1/6 oz. each and 27 oz. per doz.

“Large”: ... Uniform in size: not less than 1-11/12 oz. each and 24 oz. per doz.

“Medium”: ... Uniform in size: not less than 1-2/3 oz. each and 21 oz. per doz.

“Small”: ... Uniform in size: not less than 1-5/12 oz. each and 18 oz. per doz.

“Peewee”: ... Less than 1-5/12 oz. each

Due to the fact that many eggs in each grade weigh more than the minimum requirement, the average will automatically be according to law.

This scale has been adjusted to comply with the Agricultural Code of California, and of the U.S. Department of Agriculture.

RELIABLE MFG. Co. LOS ANGELES 33, CALIF.