Ken Williams wrote: >On Nov 18, 2007, at 10:09 PM, Eric Wilhelm wrote: >>When you have a >>thermometer, you can take the onion out of the varnish. > >Say what?
As retold by Paul Graham <http://www.paulgraham.com/arcll1.html>: In The Periodic Table, Primo Levi tells a story that happened when he was working in a varnish factory. He was a chemist, and he was fascinated by the fact that the varnish recipe included a raw onion. What could it be for? No one knew; it was just part of the recipe. So he investigated, and eventually discovered that they had started throwing the onion in years ago to test the temperature of the varnish: if it was hot enough, the onion would fry. An onion in the varnish is a deleterious specification that is retained because it's always been done that way, even though the reason for it having been done in that suboptimal way no longer exists. There's a similar story somewhere about a flywheel design that included a small hole drilled in the wheel that made it slightly unbalanced. The hole was being faithfully reproduced from the prototype, which had been manufactured slightly unbalanced leading the design engineer to drill out some mass to correct it. -zefram
