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
The history of the television can be dated back to the late 1800âs when inventors experimented with ways to have signals transmitted to a receiver. In fact, the first coaxial cable (commonly used to distribute cable TV signals) was invented during this time. The first actual transmission of images was successfully completed by John L. Baird in 1925, which led to rapid developments in television in subsequent years.