und 1875 to 1876 when he built models and demonstrated technical feasibility. His early working samples enabled people to talk to each other over wire conductors across distances that far exceeded the range of direct human speech and hearing. Experimental development would con- tinue throughout the late 1800s and into the 20th century as patents were granted and the first services became available. From the start, the telephone industry was dependent on lines, simply two pair of wires connecting two telephone instruments. Over time, it became obvious that if all the lines were connected to a single, centralized location where any telephone user could be connected to any other user on demand, service and usefulness would be greatly improved. With this capability, the central office (CO) came into being. Ten to twelve years after Bell's initial experiments, Guglielmo Mar- coni read about and began experimenting with Hertz' work with electromagnetic waves. Marconi believed that magnetic waves could free telegraphy from the constraints of wire and cable. After significant development work in the 1880s, and a convincing demon- stration of sending signals over water between the shore and an island in Bristol Channel 8.7 miles distant, he changed the name of his company, "Wireless Telegraph and Signal, Ltd." to "The Marconi PRACTICAL IP AND TELECOM FOR BROADCAST ENGINEERING AND OPERATIONS Wireless Telegraph Co. Ltd." He received an English patent on the wireless in 1896. Farnsworth and Zworykin conceived television in the early 1900s. However, neither knew of the others work, and it was well into the 1930s before serious experimentation was started on today's so-called "analog" television system. Radio had become a commercial success both in terms of broadcasting and receiver manufacturing. In add- ition, the art and science of broadcasting audio or speech using electromagnetic waves was well known. Most of the experimentation was about getting pictures-"video" over the same medium. Early telephone companies built and i