The Needles the Isle of Wight, often photographed by visitors, and are featured on many of the souvenirs sold throughout the island. The main tourist attractions of the headland itself are the two gun batteries, the experimental rocket testing station, and the four Coastguard cottages owned by the National Trust. A branch of the National Coastwatch Institution is also based at the Needles, sited near the New Battery and Rocket Testing Site on High Down. The Needles – Landmark Attraction (previously known as The Needles Pleasure Park) situated at the top of the cliff at Alum Bay is a small amusement park.
History of the Tesla coil frequency, which lighted a Geissler tube. This system, patented by Tesla on September 2, 1897, was the first use of the "four-circuit" concept later claimed by Guglielmo Marconi. However, Tesla was mainly interested in wireless power and never developed a practical radio "communication" system. He never believed that radio waves could be used for practical communication, instead clinging to an erroneous theory that radio communication was due to currents in the Earth. Practical radiotelegraphy communication systems were developed by Marconi beginning in 1895. By 1897 the advantages of narrow-bandwidth (lightly damped) systems noted by Crookes were recognized, and resonant circuits,