Although it was invented by Edward Calahan in 1863, it was unveiled in New York City in 1867. The stock ticker machine was later improved by Thomas Edison in 1869 and was widely used until the 1970s, when it was gradually replaced by computer terminals. The machines were able to communicate current prices of stocks, which previously had been handwritten, or expressed verbally, and could transmit and ultimately print the quotes at one character per second. The great significance of the invention of the ticker machine is that it enabled the dissemination of prices across a large audience. Stock prices could be known by buyers near real time, allowing the markets to become more efficient and competitive.