Janice, my sister, had been pestering her husband, a carpenter, for more than a decade to build a screen door for the kitchen.
One day, to her delight, he built and installed one in less than two hours. It was both practical and pretty. She glanced towards the front door and wistfully remarked that one would look good there, as well.
"Are you kidding?" he gasped. "You can't just whip these things up, you know. It takes ten years to build a door like this."
Magnetising metalsIn 1744, Gowan Knight presented his research on magnetising metals to the Royal Society. The method he discovered for permanently magnetising hard steels. The use of steel instead of soft iron greatly improved the otherwise crude compass needles used by England's Royal Navy, which then had a much longer magnetized life. Knight took out a patent for his compass in 1766. He devised better ways to suspend compass needles, and introduced the rhomboid shape now common for compass needles.Reference: Philosophical Trans., No. 474, p. 161 |
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