Radio room time only clock with a 12/24, 6 inch engraved dial made by the Chelsea Clock Co., Boston, Mass., serial number 221473 (serial number matches on both case and movement) which places it within the year dates 1935-1939. The serial number was originally 221454, but the 54 was stricken out and the 73 numerals added above. Cast brass case, cleaned and lightly polished. Fast/ slow adjustment is located on the middle right clock face. Second hand movement and white hand for indicating Greenwich Mean time, eight-day time-only mechanism. Screw bezel to facilitate the clock hands and key wind. Minor wear on clock face below the key wind. Marked Chelsea just below clock center. Good working order and keeps accurate time. Comes with vintage winding key.
The Radio Act of 1912, initiated after the sinking of the Titanic, mandated that all seagoing vessels must continuously monitor distress frequencies. A further result was the development of the radio-room clock. This design features two 3-minute periods (marked in red) which are designated silent periods-times when only distress signals may be transmitted.