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Spider silk crosshairs, even when properly sealed, were often less durable than other crosshair materials. “I have with great difficulty, and patience, placed a reticule of spider’s web (the first ever executed), in the focus of this instrument!” Not one to break the chain of claiming the discovery, Andrew Elliot - another astronomer - would go on to write to Thomas Jefferson in 1802:
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I have hitherto found no inconvenience from the use of it, and believe it will be lasting, it being now more than four months since I first put it in my transit telescope, and it continues full extended, and free from knots and particles of dust.” “I have with no small difficulty placed the thread of a spider in some of my instruments, it has a beautiful effect, it is not one tenth the size of the thread of the silkworm, and is rounder and more evenly of a thickness. įrom a report read to them in 1785, we hear: He was an active member of the American Philosophical Society in Philadelphia, and quite frequently gave reports to them on his various discoveries and lightbulb moments (.lightbulbs to be invented later). Instead, even later than Gascoigne, Malvasia, and Fontana, another astronomer would claim credit for spider silk crosshairs.ĭavid Rittenhouse, as you may remember from The Incident with Charles Peale, was a famous astronomer at the time.
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However, news of all the preceding inventions did not travel far and fast enough. Unfortunately, this author is not fluent in Italian. Experiments aplenty ensued.Ī while later, in 1755, an Italian named Felice Fontana wrote a proposal for using a spider web inside a leveling instrument, as recorded in the “Catalogue of the Royal Cabinet of Physics and Natural History” (“ Saggio del real gabinetto di fisica e di storia naturale ”). The silver wires of the time were far too thick for the system to work accurately, and he was in need of thinner lines. His was meant to be combined with a pendulum, to time the movements of planets and stars across empty pockets of space. In 1662, detailed in the Ephemerides, Marquis Carlo Malvasia experimented with creating a grid reticle. Many of his papers were destroyed during the Great Fire of London twenty years later. Gascoigne and his fellow astronomers all died before or during the English Civil Wars, with Gascoigne himself dying in 1644.
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While he may have been the first to see spiderwebs in his telescope and the first to dream about its utility, he may never have discovered how to purposefully install the fine threads of spider silk. “This is an admirable secret which, as all other things, appeared when it pleased the All Disposer, at whose direction a spider’s line drawn in an open case could first give me by its perfect apparition, when I was with two convexes trying experiments about the sun, the unexpected knowledge.” He wrote to his friend William Oughtred , He noticed at once the thinness of the web, and set about to make the first astronomical micrometer. During the day, a spider had spun a web inside the tube of his telescope. In 1639, about 30 years after the first telescope patent, an Englishman named William Gascoigne saw inspiration. They tried silk, hair (human or animal), thin brass plates, wires of precious metals (silver being most common, platinum to come later), and probably other stuff that they didn’t want written down. For decades, researchers tried finding thinner and thinner wires, so they could line up the stars without crossing them out of view. Unfortunately, those same wires appeared incredibly magnified inside a telescope. These innovations included such advancements as a tube with some metal wires crossed inside, both to form a crosshair and control the user’s sight alignment. This was especially important for the sextant. When using the architectural and astronomical tools of the time, travelers and tradesmen figured out ways to make sure you were looking at things in the same way, for repeatable visual measurements. By then, they were well aware that measuring something requires a frame of reference, with a starting point to measure from. And they succeeded.Īfter years of just looking at things (and occasionally drawing them), people started finding ways to measure those heavenly bodies using their telescopes. Not much later, those same astronomers and experimenters started figuring out how to get the telescope to focus properly, inside and out. Within weeks, many other people filed patents, claiming that they had invented it instead. A long, long time ago, someone patented the telescope.