Malted milk mixer or plunger style mixer. Glass container, cylindrical, with measuring line on front, marked in 2 ounce intervals between "12 oz." and "2 oz.". Line near top of cylinder is marked: "DO NOT FILL ABOVE/THIS LINE". Bottom of cylinder is marked: PATENT NO./H (over) A/5045/2/1890307". Bottom also has sticker with "421" handwritten on it. Accompanying metal cap fits on top, into lip in cylinder, does not screw on. Flattened top, angled sides, with hole in center to allow mixer to be moved up and down for mixing action. Mixer is comprised of cone-shaped metal plate with slits around perimeter, attached in center to bent wire shaft, with bent handle at top. Top of cap is embossed: "MALTED MILK/MIXER" and stamped: "PAT'D PEND". Mark on bottom is likely the "H over A" mark of the Hazel- Atlas Glass Company (H is worn at top), of Wheeling, West Virginia.
Patent Number US 1890307 A, December 6, 1932, Phillip B. Shailer and Harry P. Troendly, Wm D Gibson Company, Chicago, Illinois, for "Mixing device".
Maker is Hazel-Atlas Glass Company of Wheeling, West Virginia, which had manufacturing plants in Wheeling, WV; Washington, PA; Clarksburg, WV; Zanesville, OH; Grafton, WV; Ada, OK; Pomona, CA; Blackwell, OK; Lancaster, NY; Oakland, CA; Montgomery, AL; and Plainfield, IL.