I recently did a repair on this Seth Thomas movement. Its the best looking one Ive come accross and it opens up a few questions about what progress was made over 100 years or so. Firstly Ill itemise what I like about the ST Movement…
- Has big cogs so they dont need to be cut as accurately and wear more efficiently.
- Uses a lyre arrangement for the top and bottom plates to save materials and improve access for assembly and maintenance
- Has loop end springs so that you dont need a spring barrel complicating things
- Has a simple accessible escapement mechanism front mounted so you can see it and get to it if required
- A fair amount of it is made by hand e.g. the levers controlling the chime sequence. Adjustments are manual and dont involve fixings – you just bend wires.
- The escapement cog is held in place with a bent bracket – hilarious, its supposed to be an area where things are particularly accurate but the USA seemed to have ignored this and its fine.
- Looks fantastic.
Ok all this is typical of an Amercan movement from Walsh or Ansonia or Thomas around 1850. I think this one is a little later at 1875 but lets say 100 years go by.
So lets compare this to the Perivale style movement of 1950. Its a very typical one of the period and Ive selected one with exactly the same chime features.
- Its machine made for the most part
- It uses probably the same amount of material
- The cogs are smaller and so wear out of tollerance more quickly than the ST clock
- The smaller cogs are particularly sensitive to dust and dirt. The forces at the end of the drive chain are very weak so a build up of obstacles such as pollen and airborne particles can stop the clock.
- The springs are in barrells which serve little purpose other than to hinder access to them.
- Its a nightmare to work on without taking it completely apart
- Non removeable rivets are used on components preventing replacment when worn. Its designed with a finite lifetime in mind.
- Its no oil painting
Overall its a win for simplicity and innovation on the part of the USA.
The Perivale is ok and in its defence is more compact, however, I know which one I would prefer in my wall or mantle clock.