Bell's Telephone Invention Asphalt T-Shirt

Acoustic telegraph, telephone - the invention of Alexander Graham Bell. Bell was involved in acoustics from an early age. Many of his close relatives, including especially his mother and his wife, were deaf. It profoundly influenced his work. Bell, like his grandfather and father, delved into research on hearing and speech. He became a widely recognized elocution teacher. He experimented with a "phonoautograph", a device that draws sound waves on a smoked glass. It has inspired him to search for a method of converting sound waves to undulating electrical current. As telegraphy popularized, it's main limitation became more and more severe - the ability to transmit only one signal at a time. It was due to a pure accident, when during one of the experiments on a solution for the limitation, his assistant plucked a reed into electromagnet's field and Bell heard overtones, despite the fact the electric circuit wasn't intermittent. He realized that if it is possible to transmit harmonic sound moving one reed in a magnetic field, then it should be possible to also transmit more complex sound - human voice. Later experiments led him to develop a telephone that he patented in 1876. The T-shirt is a part of the Breakthrough invention collection created to commemorate key discoveries of science and technology. It presents a drawing from the original patent application.