flat-topped signal
51Invention of radio — Great Radio Controversy redirects here. For the album by the band Tesla, see The Great Radio Controversy. Contents 1 Physics of wireless signalling 2 Theory of electromagnetism …
52theatre — /thee euh teuhr, theeeu /, n. theater. * * * I Building or space in which performances are given before an audience. It contains an auditorium and stage. In ancient Greece, where Western theatre began (5th century BC), theatres were constructed… …
53Opto-isolator — This article is about the electronic component. For the optical component, see optical isolator. Schematic diagram of an opto isolator showing source of light (LED) on the left, dielectric barrier in the center, and sensor (phototransistor) on… …
54Opening of the Liverpool and Manchester Railway — The Duke of Wellington s train and other locomotives being readied for departure from Liverpool, 15 September 1830 The opening of the Liverpool and Manchester Railway (L M) took place on 15 September 1830 …
55Diffusion of technology in Canada — This article outlines the history of the diffusion or spread of technology in Canada. Technologies chosen for treatment here include, in rough order, transportation, communication, energy, materials, industry, public works, public services… …
56bridge — bridge1 bridgeable, adj. bridgeless, adj. bridgelike, adj. /brij/, n., v., bridged, bridging, adj. n. 1. a structure spanning and providing passage over a river, chasm, road, or the like. 2. a connecting, transitional, or intermediate route or… …
57Egypt, ancient — Introduction civilization in northeastern Africa dating from the 3rd millennium BC. Its many achievements, preserved in its art and monuments, hold a fascination that continues to grow as archaeological finds expose its secrets. This article… …
58Flag — A flag is a piece of cloth, often flown from a pole or mast, generally used symbolically for signaling or identification. The term flag is also used to refer to the graphic design employed by a flag, or to its depiction in another medium.The… …
59Song Dynasty — This article is about the Northern and Southern Song Dynasties. For the Southern Dynasty, see Liu Song Dynasty. Song 宋 ← …
60Charlie Macartney — Personal information Full name Char …
