Excerpt of 'Innovate Like Edison'

— -- Introduction: Turning on the Light

If we all did the things we are capable of doing we would literally astound ourselves.— Thomas Edison

At one thirty a.m. on October 22, 1879, everything was ready for the astounding experiment that would change the world forever. Thomas Edison, age thirty-two, and his colleagues Charles Batchelor and Francis Jehl, huddled around a series of glass tubes, gauges, and wires suspended on a tall wooden stand in the middle of Edison's Menlo Park, New Jersey, laboratory. Edison focused intently on a prototype, pear-shaped light bulb mounted at the upper edge of the stand, carefully checking the partial vacuum seal at its base. Protruding from the hand blown glass bulb were two razor-thin platinum lead-in wires, connected inside the bulb to a carbonized cotton filament no thicker than a human hair. Eyeing the lamp for a moment, Edison was satisfied that the connections holding the bulb's fragile filament in place were intact. Edison asked Jehl, "Are you ready?"

"Ready," he replied.

Jehl began evacuating oxygen from the glass lamp by pouring mercury into a long tube at the top of the stand. As mercury flowed through the tube, it slowly drew oxygen out of the lamp, creating a vacuum. They watched as large oxygen bubbles percolated through the viscous liquid, gradually giving way to smaller bubbles as the inner atmosphere of the lamp was voided of air. To hasten creation of the vacuum, Edison lit an alcohol burner, drawing the small, steady flame across the exterior of the glass bulb, warming it to remove any moisture within the bulb. Large bubbles suddenly surged into the mercury as heat from the burner drove more air out of the bulb.

Activating a battery sitting on a nearby table, Edison connected a wire running from one pole of the battery to one of the razor-thin platinum lead-in wires, taking a second wire from the battery's other pole and briefly touching it against the second lead-in wire. Current flowed upward, warming the filament, its red glow gradually ridding the carbonized cotton of any gases that could alter the vacuum. Edison repeated this filament-warming process several times until no more bubbles were visible in the mercury.