Mercury Compensating Pendulum

Oldtime

Registered User
Jul 20, 2003
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Hi all, I have a crossed mercury tubes Compensating pendulum. I am not sure the unmarked clock that came with it was the original clock with this pendulum.I have read the 400 day repair guide,and it shows this pendulum with a Becker clock,but really does not say much else.The Horolovar collection book states, patentee,if any is unknow.I would like to find out what years this pendulum was made,and which clocks can this pendulum be properly used with. Does anyone know of any book,etc.other than the ones listed where I can find more information.I read this may be one the more rare 400 day pendulums made,I know that information on them is rare. Thanks for any help.
Joe Coppa
 

Oldtime

Registered User
Jul 20, 2003
30
0
0
Hi all, I have a crossed mercury tubes Compensating pendulum. I am not sure the unmarked clock that came with it was the original clock with this pendulum.I have read the 400 day repair guide,and it shows this pendulum with a Becker clock,but really does not say much else.The Horolovar collection book states, patentee,if any is unknow.I would like to find out what years this pendulum was made,and which clocks can this pendulum be properly used with. Does anyone know of any book,etc.other than the ones listed where I can find more information.I read this may be one the more rare 400 day pendulums made,I know that information on them is rare. Thanks for any help.
Joe Coppa
 

John Hubby

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Joe, there were two versions of the crossed tube mercury pendulum. The one shown in the Repair Guide is usually found with Gustav Becker clocks, and will not have a serial number on the bottom cover. Note that the disc has square edges.

The other one was made to be fitted to Kienzle clocks. The main difference is that the disc has the upper edge chamfered at a 45 degree angle. The topworks are identical to the GB version, as is the bottom disc cover, which will have a serial number stamped in it. These serial numbers usually match the serial number of the Kienzle movement. One of these was on eBay in December and the photos are still there today for everyone to look at item no. 6591987552.

Both designs use steel rings inside the disc to provide pendulum mass. These rings are interchangeable as the diameter of both pendulum discs is the same. The rings can be added or removed to change the weight of the pendulum and thus change the rate for timekeeping. In fact the supplier for these (and for the typical Kienzle disc pendulums) made a kit that was supplied to jewelers so they could regulate the clocks before sale. I have one of the original kits with instructions.

As to when these were made, the only reference I have come up with so far is from a 1926 article that indicates they were introduced around 1912. From matching Kienzle serial number data my estimate is they were made from around that date to as late as the early 1920's. So far we have not uncovered any patents for these.

If would be good if you could post a photo.

John Hubby
 

Oldtime

Registered User
Jul 20, 2003
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Hi John, Thank you for your reply,it is a big help. I will send a photo of my clock early next week. For now I can tell you that my clock looks the same as the one you refered me to on that ebay listing. My pendulum has a number,but does not match the clocks number.My clock and pendulum is equally very tarnished unlike the one on ebay.Also one of the mercury vials on mine is stained,or tarnished on the inside. Being that they are sealed vials,and mercury is bad stuff I think it will have to stay that way.I am looking foward to restoring this clock. I am grateful for your help. I will send photo's next week.
Joe Coppa.
 

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