Well, there is the thermal expansion property of steel. If I recall, it's something like .0000065 inch per inch per degree Farenheit. I remember learning that back when I was a land surveyor. The 300' steel tape we used would expand or contract and we needed to figure that in. Also, sometimes, curvature of the Earth. This stuff gets important when you have to close a survey to less than 3/100 of a foot and a degree or so in several miles line distance.
I suppose that could affect the clock during large temperature swings. I'm sure the same kind of thing affects brass, but I haven't committed it's properties to memory.
My shop is only heated with a small space heater and is a fairly large shop, so I see cold temps out there in winter. I haven't noticed a difference when I bring the clocks into the warm house, but I haven't been looking for that small of a difference.
I'm at the point where I'm usually just very happy they keep ticking. :biggrin:
Plus, I must have latent obsessive/compulsive tendancies. I actually like fussing around with them. I guess I'd be dissappointed if they all just kept perfect time. It's almost like each one has it's own "timekeeping personality".