INSPECTION, MAINTENANCE AND RECHARGING FIRE. EXTINGUISHERS. The provisions of this bulletin apply to the selection, installation, inspection, maintenance and testing of portable extinguishing equipment. This guide is prepared for. the use of persons charged with selecting, purchasing, installing, and maintaining. portable fire extinguishers. The following requirements are excerpts from the National.
On 27 August 1920, regular wireless broadcasts for entertainment began in Argentina, pioneered by the group around Enrique Telemaco TelÃ©maco, susini and spark gap telegraphy. Stopped on 31 august 1920 the first known radio news program was broadcast by STATION, 8mk the unlicensed predecessor OF (WWJ) am In, Detroit. michigan
Twenty years after the telephone was invented and music was first sent down a telephone line, Guglielmo Marconi sent radio signals. Marconi (1874-1937) was born in Italy and studied at the University of Bologna.he next year Marconi opened the first radio factory in Chelmsford, Essex and established a radio link between Britain and France. A link with the USA was established in 1901. In 1909 Marconi shared the Nobel prize in physics for his wireless telegraph. Marconi became a wealthy man.