I have a waterbury mechanical mantel clock from late 1800s. Family heirloom. Works. 8 day clock, needs winding every 7 days, the last day, it starts to lose time, especially the last 1/2 day. Well, the last 1/2 hour, probably - it works pretty well overall.

I have the pendulum that I inherited, and with adjustment it keeps time fairly well. However, it runs at about 72 beats per minute.

How hard would it be to change it to 60 beats per minute. What would need changed. I don't expect to change it, or that it would be easy, just wondering if anyone knows much about them.

Maybe more importantly, or of more interest - why would the clock be built to run at 72 rpm to keep time instead of 60 rpm? Is that something to do with music? Human heartbeat?

just seems to me that if I went to the trouble to manufacture a clock, I would make it 60 rpm beat for so that the beat would be equivalent to seconds.

The smaller the clock the faster the pendulum will swing.
There is any logical way to make it swing ounce a second.
In watches a wheel takes the place of the pendulum.
It's all in the gearing.
Their intentions weren't to make the pendulum swing every second but to keep time.
The spring gives the pendulum the forse it needs to swing the other direction.

Here's a link to a guy that makes clocks and all manner of things.
I'm sending the link for the clock he made from raw materials.

I don't think it would be hard especially nowadays to size a clock so that the pendulum swings at 60 RPM. I don't think it would have been that hard back then either. Even if it wasan iterative process to do it. I wonder how much of the parts simply relied on what they could make the size they could make with simple metallurgy. And reusing the same machinery for a lot of years. These clocks go back to like the 1870s I think. The earliest I saw mentioned was the 1840s.

I would have tried to make that tick talk right on 60.