This Day in Geek History: April 15
Leonardo da Vinci is born in Vinci, Florence.
The Reverend William Stukeley, who will become one of the first biographers of Isaac Newton, has a conversation in which Newton recalls “when formerly, the notion of gravitation came into his mind.” In Stuckeley’s Memoirs of Sir Isaac Newton’s Life, will write that Newton said, “It was occasioned by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself. Why should it not go sideways or upwards, but constantly to the Earth’s centre.”
Italian engineer Enrico Forlanini rises forty feet (12m) off the ground in a steam-driven helicopter of his own invention. The 7.7lb (3.5kg) vehicle is driven by coaxial rotors powered by a single two-cylinder steam-engine which must be charged to ten atmospheres of pressure to rise and remain airborne for twenty seconds.
The General Electric Company (GE) is founded in New York. The company is the result of a merger of Edison Electric Light Co. and the Thomson-Houston Electric Company. Visit the official General Electric website.
Dr. Lee De Forest demonstrates his Phonofilm sound-on-film process to the first paying movie audience at an invitation-only event at the Rialto Theater in New York City. The program includes eight short films with sound and the Paramount film Bella Donna, featuring an introduction by the head of Paramount studio, Adolph Zukor. De Forest’s system incorporates a Thalofide photoelectric cell which reads the soundtrack from film.
The first helicopter flight to last for more than an hour takes place in Stratford, Connecticut.
The first B-52 prototype takes its first test flight.
The first McDonald’s opens in Des Plaines, Illinois. On its first day of business, the restaurant sells US$366.12 worth of fifteen cent hamburgers and ten cent French fries. Visit the official McDonald’s website.
The city of San Diego, California becomes the first city in which all telephone customers could dial their own calls without the assistance of an operator.
Canon Business Machines of Japan announces the first hand-held pocket calculator in a press release. The four-function Canon Pocketronic features a built-in printer. At the heart of the device are integrated circuits developed by Texas Instruments (TI). The Pocketronic is one of the first calculators to use Large Scale Integrated (LSI) Circuits to miniaturize the device for portability. Read more at the Old Calculator Web Museum. Price: US$400
The first annual West Coast Computer Faire is held over three days at the Brooks Civic Auditorium in San Francisco, California. The event is attended by 12,750 people. The Faire features the debut of the Apple II from Apple Computer, which features 16KB of memory, BASIC, a built-in keyboard, and eight expansion slots. It also features several notable innovations, including built-in high-resolution color graphics. Price: US$1,300