.....In long pipe lengths swings of 1-5degrees can cause thermal expansions up to an inch. Its the length of material that becomes the driving factor- and not directly proportional, if my memory is correct. An interesting problem to be reviewed, none the less.
P.S.
That clock is both very impressive and beautiful- sadly in todays watch world these often two do not go hand-in-hand (too much impressive with too little beauty)