As a result of the success of the first demonstration a further test was requested on Salisbury Plain at the beginning of September. This time representatives from the War Office and the Admiralty were also present. In view of the additional observers, Marconi used parabolic reflectors at the transmitter and receiver to show the directional properties of the waves. This was important to show that secrecy could be maintained during transmissions. The use of this technology limited the range to only about two and a half kilometres. Further tests six months later used balloons to raise the height of more conventional antennas. This time a range of over seven kilometres was achieved.The next demonstration was made to the press. This was very successful, partly because of the novelty of being able to communicate electrically without any intervening wires. The effect was also enhanced by the showmanship used in the performance as both transmitter and receiver were housed in black boxes. As a result Marconi became an instant celebrity.Up until this time the new Hertzian or radio waves used by Marconi had not been put to any real use. Then in 1897 it was decided to test the new system and see if it could provide a reliable link across various stretches of water. If this were successful it would save on the installation of expensive submarine cables. In some of the first of these tests across the Bristol Channel, Marconis system proved to be very successful, further enhancing his image.