Jefferson Integer

By Roger Russell

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Catalog Number 580-231

The Integer was also designed by Dave Chapman’s organization after the success of the Jefferson 500. Mr. Chapman’s design firm was respected internationally and served such clients as Alcoa, The Parker Pen co., The Hamilton Beach Co., The Corning Glass Co., Johnson Sea Horse Motors, International Harvester and Montgomery Ward. The Integer is referred to as a cordless electric clock. It is spring driven, but uses batteries for power. As the spring unwinds, a set of contacts closes and a solenoid then acts to rewind the spring. The contacts are then disconnected. This cycle repeats automatically with an audible "clunk" about every 2-1/2 minutes.

Both chrome and gold versions have been found and they each have the same catalog number. The dial cover is domed plastic and has black numbers at 3, 6, 9 and 12 o'clock with black dots for the other hours. The hour and minute hands are black and the second hand is red. The clock face is slightly conical rising to a peak at the center. It has a gold finish with 60 radial minute lines. The lines are white near the center and black near the edge. A plastic base raises the clock 7/16" above the mounting surface.

Because of the weight and color of the clocks, they could be thought of as being made of brass or steel. However they are made of the same die cast zinc alloy as the Golden Hour. See my page showing a cross section and a metal analysis. The cases are either polished chrome plate or gold on the outer surfaces and satin chrome plate or gold in the area immediately surrounding the dial. The base is high-impact plastic (Cycolac) with a satin surface. The base is black for the chrome version and white for the gold version.

The battery cover states "Use Jefferson #580-700 or Mallory #RM12R cells". These were 1.35V mercury cells and are no longer available. The picture shows the battery cover removed and two AA cells that can be substituted. They will operate the clock for about a year.

The Integer was introduced in the early 1960's. Size is 5-1/4" high and 4-11/16" in diameter at the widest part near the base. Weight is 2.1 lbs. In 1962 it retailed for $29.95