This Day in Geek History: April 7
The Academy of Sciences in France adopts the metre as the base unit of the metric system. There wasn’t any uniformity in French measurements prior to the Revolution. Delambre and Méchain measured an arc of the meridian from Dunkirk to Barcelona, in order to define the metre as one ten-millionth the distance between the poles and the equator.
English pharmacist John Walker sell the first friction matches, which he invented the previous year while trying to produce a readily combustible material for fowling-pieces. The first match he created was the wooden stirring stick used in a mixture of potash and antimony. In an attempt to remove a dollop of the mixture on the end of the stick, he scraped it on the stone floor, and it ignited. However, he won’t ever patent the invention, and he’ll never produce more matches than he can sell in his pharmacy.
The U.S. government cancels all amateur wireless transmission licenses, the day after declaring war on Germany and entering the first World War.
The first flight (with stops) to successfully fly completely around the world takes off.
The first public transmission of television pictures over telephone lines is demonstrated using a prototype two-way television system dubbed “The Picture Telephone” by the American Telephone & Telegraph Company (AT&T) for a group of newspaper reporters and dignitaries. The transmission is sent over 200 miles, from New Jersey to Washington D.C. It’s the first inter-city transmission of video images, as well as the first public television demonstration ever seen outside the U.K. Secretary of Commerce Herbert Hoover and AT&T president Walter Gifford use the connection to speak to each other. “Today we have, in a sense, the transmission of sight for the first time in the world’s history,” Hoover said. “Human genius has now destroyed the impediment of distance in a new respect, and in a manner hitherto unknown.” As well as being displayed on a small screen, the images are shown on an array of lamps three feet high and two feet wide, seen to the right of Dr. Herbert Ives, head of television research at AT&T. While the quality of the small images in the scanning-disc viewer are described by the New York Times on April 8th as “excellent”, the large screen images were “not so good.” Newspapers across the nation will cover the story of AT&T’s achievement. Herbert Ives is the AT&T researcher who led the television project.
Capitol Tower, the headquarters of Capitol Records in Hollywood, California, is dedicated. The building, designed to resemble a stack of records, is the first circular office tower in the U.S. It’s thirteen stories tall and ninety-two feet in diameter. At night, a light at the tip of the tower blinks the letters “H-O-L-L-Y-W-O-O-D” in Morse Code.
The first atomic generated electricity is produced at the Los Alamos Scientific Laboratory in New Mexico. The experimental model uses a “plasma thermocouple” in the reactor rather than a full scale turbine, but it only produces enough electrical power for a light bulb.
A radar signal is bounced off the Sun for the first time from Stanford, California.