Superconducting magnet issues "shaken" out of them, until they are eventually able to operate reliably at their full planned current without experiencing quenches. Although the idea of making electromagnets with superconducting wire was proposed by Heike Kamerlingh Onnes shortly after he discovered superconductivity in 1911, a practical superconducting electromagnet had to await the discovery of superconducting materials that could support large critical supercurrent densities in high magnetic fields. The first successful superconducting magnet was built by G.B. Yntema in 1955 using niobium wire and achieved a field of 0.7 T at 4.2 K. Then, in 1961, J.E. Kunzler, E. Buehler, F.S.L. Hsu,
Lowest temperature recorded on Earth 1960, held the record until a temperature of was measured at the Soviet Vostok Station, on the Antarctic Plateau, on July 21, 1983. This remains the record for a directly recorded temperature. In 1904 Dutch scientist Heike Kamerlingh Onnes created a special lab in Leiden with the aim of producing liquid helium. In 1908 he managed to lower the temperature to less than −269 °C (-452.2 F, 4 K), which is less than four degrees above absolute zero. Only in this exceptionally cold state will helium liquefy, the boiling point of helium being at −268.94 °C (-452.092 F). Kamerlingh Onnes