Mark Frank | Astro-skeleton, Seconds hand correction @MarkFrankclocks | Uploaded 2 years ago | Updated May 12 2024
This video shows how a two second period can be converted to a one second readout on the dial It is the reverse of what is commonly known in horology as a Coup Perdu escapement where a 1/2 second pendulum is made to show a one second readout on the dial. Coup Perdue is French for lost beat, where every other beat of the 1/2 second pendulum is skipped to get the one jump second readout from the seconds hand on the dial.

The action on the video is uneven because it is the first trial, the escapement is not moving at a constant speed and before adjustments were made on the pallets to get a perfect one jump second. It is simply a concept demonstration.

This was created because during the current debugging process the seconds hand was moving erratically, coasting past the designed two second intervals, and even sometimes moving backward. The reasons for this are discussed in detail here: http://www.my-time-machines.net/astro_04-21.htm .
One of the serendipitous consequences of this fix is that the clock face now looks "correct" in that the second hand jumps each second instead of every two seconds which was the intended consequence of the slower two second compound pendulums. I had decided on the slower pendulums as they have a more hypnotic, pleasant visual effect than a one second period, which to me looked too busy and distracting.