Thursday, January 5, 2012

Here's Looking at You!

At left is an 18th Century, single draw, ten sided, terrestrial telescope made by Nairne & Blunt of London, made of brass and hardwood. Its objective lens is 7/8" in diameter; overall length when closed is 24" and about 27" in use. It is estimated at  the power at about 10X. It had state-of-art optics at the time of the American Revolution.

It was made by Nairne and Blunt of London, instrument makers who formed a partnership and conducted business from their shop at 22 Cornhill in London from 1774 to 1793.

In the early, 1770's, Nairne patented several electrical machines, including an electrostatic generator that supplied either positive or negative electricity, intended for medical use. He also constructed the first sucessful marine barometer that James Cook took on his second voyage to the South Pacific.

Nairne also is credited with creating the first rubber eraser! The earliest references to rubber in Europe were in 1770, when Nairne was selling cubes of natural rubber at his Cornhill shop, at an incredibly high price of 3 shillings per half inch cube! Interestingly enough, before rubber erasers, people used bread crumbs!

He was a regular contributor to the Philosophical Transactions of the Royal Society of London, and elected a fellow in 1776. He enjoyed an international reputation and corresponded with Benjamin Franklin, another scientific inventor of the times. Nairne made a set of magnets and a telescope around 1758 for Franklin, and on Franklin's recommendation, he was asked to supply instruments for the fire-damaged collection at Harvard University.

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