#23935
Malgus
Malgus
Survivalist
member8

Whirl,

No worries, bro… I’d probably mess my britches if I had to wear that thing… I’m hard on equipment too. Something so delicate and perfect wouldn’t last too long around here, I’m afraid…

Hey, found out something pretty cool from an engineering point of view.

Back in the late, great 17th century – and well into the 18th century – there was a problem with time-pieces, especially the ones that were being used to find longitude at sea. The tiny balance wheel would expand in the heat and contract in the cold. Tolerances were so fine that any change whatsoever would throw the chronometer off and thus, the ship’s navigation. It was such a problem that the English Parliament put up a bounty of 20,000 pounds sterling to whomever could solve the problem.

Enter one John Harrison, who won the prize in 1767. His solution? Differential expansion. Really an elegant engineering solution – and I admire the hell out of elegant engineering. (By the way, the 20,000 pound bounty stood for 53 years before Mr. Harrison found a solution to the problem).

The balance wheel, he created of steel, but then put a “tire” on the outside rim made of brass. The expansion of the brass was greater than that of the steel, and when done correctly, the two bands would reach stalemate in expansion/contraction and the tolerances would not change. The expansion of the brass “tire” would decrease the inner diameter, which would be resisted by the steel. Same with contraction. With the steel and brass in harmony, the chronometer would run regularly in heat or cold and thus, longitude could be calculated accurately…

Smart guy, that John Harrison…

Thought you might like that…

The wicked flee when none pursueth..." - Proverbs 28:1