Edison and the Electric Chair_ A Story of Light and Death - Mark Essig [14]
A little before twelve o'clock on many nights, two apprentices and a huge Newfoundland dog would set out for the local grocery. Menlo Park had no streetlights, electrical or otherwise, so the dog led the way with a lantern clamped in his teeth. After rousing the grocery keeper from bed, the party returned with baskets laden with soda crackers, cheese, butter, and ham. A boy fetched buckets of beer from Davis's Lighthouse, the local tavern, and the Menlo Park crew gathered for their midnight supper. After the meal Edison passed out cigars, and amid the smoke the men gossiped and told jokes. Some nights there was clog dancing, or an impromptu boxing match, or a sing-along to popular tunes. The German glassblower Ludwig Boehm might play the zither and yodel. Often "the old man"—as the workers called Edison—would sit down at the pump organ and pound out the few chords he knew. Then the boss would stand and hitch up his trousers—the signal to get back to work. Visiting reporters often got so caught up in the fun that they missed the last train back to New York and spent what was left of the night sleeping on the laboratory floor.15
Their host often chose similar accommodations, even though his wife and a warm bed awaited him just a short walk away. One of Edison's favorite locations was a small storage closet under the laboratory's stairwell. He would crawl in, pull the door shut, and sleep for a few hours on the floor. (This space doubled as his hiding spot when unwanted visitors arrived.) He also liked to stretch out under one of the lab benches, using his coat as a pillow—but not before giving his men orders to wake him if anything important developed. According to one reporter, "Life in the Menlo Park laboratory partakes more of the character of a camp pitched near the battlefield than of anything else."16
Edison (seated in the middle with a scarf around his neck) with some of his assistants at the Menlo Park laboratory, February 1880.
EVEN AFTER FOUR MONTHS of unsuccessful experiments, Edison remained convinced that platinum was the best material for an incandescent burner. Previously, he had tested his platinum burners in the open air, but when he still could not keep them from melting, he decided to try a new technique. In late January 1879 he started placing the burner within a glass container evacuated of air—for the first time, he was working on a light bulb. Earlier inventors had tried coupling a vacuum with carbon burners in an attempt to avoid oxidation, but they had trouble creating a good vacuum. Edison at first believed that his decision to focus on platinum, which did not burn, had freed him from the need for a vacuum, but by late January he began to think otherwise. He discovered that bubbles of gas were being trapped within the platinum burners, causing them to melt more easily. If he heated platinum in a vacuum, Edison reasoned, he would release the occluded gases and raise the melting point of the platinum. The available vacuum pumps—complex contraptions of glass tubing and liquid mercury—did not work well enough, so Edison devised a new one that evacuated nearly all of the air from a glass globe.17
The vacuum pump was not the only new device at Menlo Park. Although initially impressed by William Wallace's electrical generator, Edison discovered that it, like all of the other generators on the market, could not produce a current efficient enough for economical incandescent lighting. Edison and his men began to experiment on designs of their own. By the spring of 1879 they had created what Upton called "the best generator of electricity ever made," one that converted mechanical energy to electrical with very little waste. The Edison dynamo featured two large, cylindrical magnets standing on end, an arrangement