Here is a working vintage Jefferson Golden Minute \"mystery\' clock. These are late 50\'s and made of 24K gold plated zinc.
from Number 580-121This clock is the same as the Golden Helm but without the spokes around the periphery of the dial frame and with different hand styling. Because of the weight and color of the clock, it could be thought of as being made of brass. However it is made of the same die cast zinc alloy as the Golden Hour. See my page showing a cross section and a metal analysis. The base and dial frame are plated with 24kt gold in a brushed satin finish. See my Gold Reference Page for information about gold and karat ratings. Two different inner dial frame rings have been found. They are also made of a die cast zinc alloy and plated with either chrome or 24 kt gold. They are engraved at 3, 6, 9 and 12 o\'clock as well as radial lines at the other hours and filled with luminescent paint. A luminescent line is also painted on the hour and minute hand. These can be seen in the photo above as a very light greenish white. The luminescent material is actually radium paint and is still radioactive but now glow very little or not at all in the dark. However, the radium is still active and has a half life of 1600 years.The glass is mounted in a steel, nickel plated ring gear. It is single strength select grade glass and is 3/32\" thick. Replacement glass instructions are available including the purchase of shatter resistant acrylic instead of glass. The retainer ring on the back of the clock is steel, plated with 24 kt gold. The hand assembly is brass plated with 24 kt gold. The plastic bottom cover is Eastman Chemical Products Corp. “Zenite II” also known as cellulose acetate butyrate. The clock measures 7-3/8\" high and the outside diameter of the dial is 6\". Depth is 4-5/8\". It has a UL approval indicated on the base plate. The cord and plug are brown plastic. Weight is 2.1 lbs. First date of manufacture was 1955 and it sold for $24.95.The date of manufacture for most Golden Minutes is stamped on the inside of the base. The clock at the left is dated 4-6-55. This can be found by removing the two screws that hold the base plate. Sometimes the numbers are a little smeared.The clock is often powered with an International Register Company synchronous motor located in the base. Other motor sources are the Haydon Mfg. Company and Bowman Electrical Products Corporation. The output gear from the motor gearbox has 36 teeth and rotates at 1/12 rpm. This mates with the ring gear that has 180 teeth. This 5:1 reduction results in the clock face turning at the required 1/60 rpm, or one revolution per hour. he picture shows the rear of the hands and the pear shaped counterweight assembly. The minute hand is located at front of the glass and is attached to it by friction so that it can be easily turned to set to the desired minutes. The hour hand and gear assembly is located behind the glass and can turn freely. A shaft attached to the center of the glass has a gear on it that\'s in the counterweight gear assembly. The counterweight always stays in a vertical position. It provides a fixed location needed to drive other gears that advance the hour hand as the glass turns.A small counterweight of metal is attached to the rear portion of the hour hand. It\'s the same shape as the hand and can be seen in upper left portion of the picture. It serves to hold the hour hand in proper position relative to the minute hand.
