Charles Benedict Calvert telegraph, Samuel Morse and Alfred Vail. On April 9, 1844, Morse and Vail successfully tested their device by transmitting a message from the nation's capital to the Calvert home, Riversdale. This test came 45 days before the more celebrated event when Morse sent the message "What hath God wrought?" from Washington to Baltimore, along telegraph lines that ran above the Baltimore and Ohio Railroad line near Riversdale. Calvert became president of the Prince George's County, Maryland Agricultural Society and the Maryland State Agricultural Society, and served as vice president of the United States Pomological Society. He founded the first agricultural
Telegraph sounder important that a sounder make a sound both when the circuit was broken and when it was restored. This was necessary for the operator to clearly distinguish the long and short keypresses – the "dashes" and "dots" – that make up the characters in morse code. Telegraph sounder A telegraph sounder is an antique electromechanical device used as a receiver on electrical telegraph lines during the 19th century. It was invented by Alfred Vail after 1850 to replace the previous receiving device, the cumbersome Morse register and was the first practical application of the electromagnet. When a telegraph message comes