After Hertz had shown how long electric waves could be set up by the sparks of an induction coil, other scientific chaps went to work to get up a better scheme to detect them. In 1890 Edouard Branly, of France, discovered that when metal filings were put in a tube and electric waves were allowed to fall on them the resistance of the filings was lowered, and Sir Oliver Lodge, in 1894, found that this was caused by the filings being drawn closer together, that is, they _cohered_. By connecting a _coherer_ (see the diagram) as he called the filings detector, to a galvanometer and a dry-cell he was able to detect the presence of electric waves up to distances of 500 feet. [Illustration: Lightning detector] A year later Popoff, of Russia, made a receiver for studying electric storms--lightning is only gigantic electric sparks--and this consisted of a coherer, a battery, a relay and an electric bell. Popoff connected one side of the coherer with a wire which he ran up into the air, or _aerial wire_ as we call it now, and the other side of the coherer he grounded, as shown in the diagram. This was the first time that an aerial wire and a ground had ever been used in connection with a coherer. With this apparatus Popoff was able to hear the coming of storms for hours before they appeared above the horizon. About this time Guglielmo Marconi, who was only 20 years old, was going to the University at Bologna, Italy. Prof. Righi who lectured on physics there was repeating Hertz’s experiments and used Branly’s coherer for detecting the electric waves. This set Marconi to thinking and it was not long before he had an experimental wireless set of his own, thus becoming the first wireless _kid_. The chief difference between his transmitter and that of Hertz was a telegraph key which he put in the battery circuit so that he could break up the sparks into dots and dashes. He also set a reflector back of the apparatus to concentrate the electric waves into a beam to make them go in a given direction when they would be more powerful and cover a longer distance. But Hertz did the reflector stunt first. Marconi’s receiver was made up of an apparatus just like Popoff’s except that he connected an old-time Morse printing register in the battery circuit so that when the electric waves acted on the coherer the signals would be printed on a tape in dots and dashes. In his first attempts, then, to send wireless messages, young Marconi had done four things and these were (1) to see the possibilities of using electric waves set up by a Hertz apparatus for sending messages; (2) to put a telegraph key in the sending circuit; (3) to use a Popoff receiver for receiving the electric waves, and (4) to put a Morse register in the receiving circuit. These were the first big steps in building up a wireless telegraph set, but none of them formed an invention.