Thomas Edison gets a lot of credit for inventions that he didn’t actually create. One of those inventions is the stock ticker. Although Edison did invented an improved stock ticker through his invention of the “Universal Stock Printer” in 1871 to help keep track of silver and gold prices, he didn’t invent the first stock ticker. That credit goes to a man named Edward Calahan, who patented the invention in 1867.
Calahan is credited with several inventions, which isn’t bad considering he left school at the age of 11 in order to pursue his business interests. Born in 1838, Calahan was inducted into the Hall of Fame for his life’s work in 2006. Here is a look at his other inventions.
1. Ticker Tape
In order for a stock ticker to work properly, it would need to have something that could be printed upon so the stock prices could be read and understood. That’s where the invention of the ticker tape comes into this story. It wasn’t processed in numbers, however, because that kind of technology did not yet exist. Stock prices were instead transmitted over the telegraph lines and this paper strip was used up until 1970 in some areas. Even today, the electronic version with actual prices is displayed in the same way Calahan’s stock ticker initially displayed information.
2. Envelope Fasteners
Do you ever get tired of licking the glue on the back of an envelope to send a letter or pay a bill? Before glue, there was wax and other adhesives which were used to make sure the contents of an envelope stayed intact. What Calahan invented was the first envelope that could fasten itself through an interlocking mechanism. Instead of using a glue, two interlocking tongues were incorporated into the design of the envelope to keep the items within secure.
3. Door Springs
Although door springs were in use at the time of Calahan’s invention in 1889, they were a rather impractical invention. Calahan moved the springs away from a horizontal position to a more vertical position and then put manual tension adjustments that could be easily modified by the average person. This would allow a door to close on its own at a speed which the owner preferred. It could be adjusted to be faster or slower, which at the time was the only type of door spring that allowed such functionality.
4. Advertising Displays
Calahan realized that there was a lot of open space that the average business owner had which was not being used for anything. That’s where his idea of the advertising display sprang from back in 1890. It was an invention that was part stock ticker and part projector. A business owner could manipulate a series of characters on the device, which would then allow them to display advertising characters to the general public at night. Using a display wheel and a camera box, a simple lever was all that was needed to create the moving display.