I hope this isn't a stupid question, I have only recently got interested in Horology and last year began building a clock. It has a one second pendulum driven by an electronic interpretation of a Hipp Toggle. I have plenty to learn. So the question is about the pendulum and bob. I bought 1 metre of 8 mm dia Invar and had a bob made from steel 8" high x 2" dia. With the bob supported at the bottom I had to extend the invar rod with steel (1.5" 8mm steel stock and the rest steel 4ba threaded rod.) I understand that ideally the bob should be supported half way up it's height. But have I inadvertently incorporated approximate temp comp for the bob with the 4" of steel at the bottom of the rod ? It SEEMS to me that with the bob expanding upwards, its centre point will go higher, but be lowered by the same amount due to expansion of the steel element in the rod ??