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Full Scale Wind Tunnel, NASA history collection
SGT. 1ST Class Owen Olgen works on a Network Management Central (NHC) A.N.T.Y.Q. 54 which allows him to check and operate the satellite dishes
Förhandsreportage från travbanan. 9 juli 1955.
Airmen of the night, command post
A sailor in an engineering space aboard the amphibious assault ship USS SAIPAN (LHA 2) makes an adjustment to the ship's electrical generating system. The SAIPAN is on station off the coast of Liberia for Operation Sharp Edge
LASER BEAM PROFILES THROUGH TELEC
Airman Connor McDonald, 5th Operations Support Squadron
Kolton Rottinghaus, 51st Fighter Wing Safety Bird/Wildlife
A Fresh Crater Drills to Tharsis Bedrock
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Civilian protection. Section of the report center in New York City. Large signs readily identify the operators in constant touch with the telephone, electric, gas and water services. Others are connected to emergency food and housing units and the police and fire alarm systems
Civilian protection. Here is the way the report center is set up in New York City. The liaison officer keeps in touch with emergency forces which are indicated by the sings
Civilian protection. Here is the way the report center is set up in New York City. The liaison officer keeps in touch with emergency forces which are indicated by the sings
Civilian defense. Communications vital to civilian defense. The New York City Emergency Services truck displayed at the ivilian defense show at Madison Square Garden, New York, in October, is equipped with a dispatcher's desk and telephone facilities for workers sent out from the truck. It is also equipped for two-way communication with a central office
Civilian defense. Communications vital to civilian defense. The New York City Emergency Services truck displayed at the ivilian defense show at Madison Square Garden, New York, in October, is equipped with a dispatcher's desk and telephone facilities for workers sent out from the truck. It is also equipped for two-way communication with a central office
Civilian defense. War Emergency Radio Service. These three War Emergency Radio Service transmitter-receivers tuned to different wave lengths keep this Civilian Defense control center in touch with three different channels of communication. The set being operated maintains contact with state and city police and fire departments. The other two are used for communicating with sub-control centers, hospitals, and mobile field units
The air raid protective services. Auxiliary police number among their most important duties the guarding of various points where saboteurs might hope to operate. Gas tanks, power houses, telephone exchanges and water works are attractive places for anyone bent on sabotage
Civilian protection. A City of New York emergency service truck, fully equipped for rescue work
Civilian protection. This is another of the tasks for which civilian volunteer workers are trained. Their is the task of saving human life and they are equipped with the latest in equipment to make this vital task more efficient. Municipal fire and police departments will play a leading role in this training
Civilian protection. Section of the report center in New York City. Large signs readily identify the operators in constant touch with the telephone, electric, gas and water services. Others are connected to emergency food and housing units and the police and fire alarm systems
Summary
Public domain photograph of New York City, free to use, no copyright restrictions image - Picryl description
The invention of the telephone still remains a confusing morass of claims and counterclaims, which were not clarified by the huge mass of lawsuits to resolve the patent claims of commercial competitors. The Bell and Edison patents, however, dominated telephone technology and were upheld by court decisions in the United States. Bell has most often been credited as the inventor of the first practical telephone. Alexander Graham Bell was the first to patent the telephone as an "apparatus for transmitting vocal or other sounds telegraphically". The telephone exchange was an idea of the Hungarian engineer Tivadar Puskás (1844 - 1893) in 1876, while he was working for Thomas Edison on a telegraph exchange. Before the invention of the telephone switchboard, pairs of telephones were connected directly with each other, practically functioned as an intercom. Although telephones devices were in use before the invention of the telephone exchange, their success and economical operation would have been impossible with the schema and structure of the contemporary telegraph systems. A telephone exchange was operated manually by operators, or automatically by machine switching. It interconnects individual phone lines to make calls between them. The first commercial telephone exchange was opened at New Haven, Connecticut, with 21 subscribers on 28 January 1878, in a storefront of the Boardman Building in New Haven, Connecticut. George W. Coy designed and built the world's first switchboard for commercial use. The District Telephone Company of New Haven went into operation with only twenty-one subscribers, who paid $1.50 per month, a one-night price for a room in a city-center hotel. Coy was inspired by Alexander Graham Bell's lecture at the Skiff Opera House in New Haven on 27 April 1877. In Bell's lecture, during which a three-way telephone connection with Hartford and Middletown, Connecticut, was demonstrated, he first discussed the idea of a telephone exchange for the conduct of business and trade.
Nothing Found.