Tinkering at the EdgesIn Europe, the Enlightenment is in full bloom, a period when people are beginning to use scientific observation to understand the world. Many are seeking to replace tired religious dogma with enlightened reason. There is also a new interest in the affairs of society. Philosophers and free-thinkers experiment with new ways to apply scientific principles to unlock human potential. The goal is a more liberating life. In America, men of wealth and education also begin to catch the scientific fever, as the latest books imported from Europe open eyes to the value of experimentation. Others are just seeking better ways to produce iron. |
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Gifted Amateur Of all America's Founding Fathers, Benjamin Franklin is perhaps the most interested in science. Starting out as a printer in Philadelphia, he founds an influential newspaper at the age of 23. As his success grows, he becomes interested in scientific advances coming out of Europe. He famously flies a kite in a lightning storm, with a metal key attached to the string, to demonstrate that lightning is a form of static electricity (top left). He invents bifocals (lower left), and a cast-iron fireplace insert that will soon be widely sold, in an improved form, as the 'Franklin Stove' (center top). His own personal favorite invention is the 'glass harmonica,' a musical instrument that makes sound by touching rotating glass bowls, each sized to produce a specific pitch. | |||||||||
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Information Spreads One reason the influence of science is spreading so rapidly is the increased availability of books on all subjects. The chart (center top) shows the growth in the number of books printed in Europe since the invention of the printing press. By the end of the 1700s, an astonishing one billion books have been printed. The printing press makes all this possible (top left), using individual pieces of metal type (lower left) to print the text for books, pamphlets and single-page newssheets. The type is assembled into blocks, using one piece of metal type for each letter in every word (center bottom). Pages are printed one at a time, then assembled into bound volumes using strings and presses (top right). | |||||||||
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Old-style Iron Furnace The arched opening in the massive stone furnace (top left) is where the liquid iron comes out, during smelting. Enormous bellows (lower left) are driven by a waterwheel to force air into this early 'blast' furnace, thus raising the temperature. The liquid iron flowing out the bottom is channeled into a series of rectangular pockets in the dirt floor (top right) where the iron cools into bars (center top). To improve strength, the iron bars are reheated using charcoal, and then beaten to drive out impurities. Charcoal, needed to achieve high temperature, is produced by stacking firewood under a pile of dirt, and then lighting a smoldering fire within the pile (lower right). This uses huge amounts of wood, leading to rapid exhaustion of the surrounding woodlands. | |||||||||
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Village Blacksmith There are only two ways to make anything out of metal in the 1700s. The simplest is to use a blacksmith's forge (left) to heat up a piece of iron bar until cherry red. This makes it soft, allowing it to be beaten into the desired shape with a hammer (center top), which is how horseshoes are made. To make a complicated or delicate shape, you begin by carving a wooden pattern. This is placed in a wooden box, with damp sand compacted around it to make a single-use mold. Heated metal can then be poured as a liquid into the mold (center bottom), hardening in the exact shape of the pattern. This method produces large objects like a kettle, but also smaller items like spoons. Silver is expensive, so most tableware is made using cheaper metals, like pewter. | |||||||||
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Gunsmithing The highest level of skill in metal-working is required to make firearms, especially the long barrel of the musket (top left). There are no drills capable of boring out the center hole of the barrel, so the gunsmith starts out with a flat, slightly tapered, bar of iron. This is bent lengthwise into a long U-shape, like a roof gutter (top right). The long edges are gradually forced together, and joined by repeated heating and hammering, an inch or so at a time (center bottom). This leaves a rough, undersized inner bore which is gradually opened up and smoothed using a set of reamers, each slightly larger than the previous one. The reamers are made from square stock, which is twisted to make spiral cutting edges (lower right). | |||||||||