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,
Harm Kamerlingh Onnes Lorentz as a subject. One of these stained-glass windows contained a portrait of Hendrik Lorentz and formulas devised by him that describe the behavior of electrons. Other stained-glass windows show the instruments to measure the splitting of spectral lines of atoms under the influence of a magnetic field is measured, the so-called Zeeman effect. He also made portraits of the physicists Albert Einstein and Paul Ehrenfest. Harm Kamerlingh Onnes characterized his artistic work with the phrase "just messing around". In 1953 Kamerlingh Onnes with Bert Nienhuis Piet Wiegman, Dirk Hubers and Frans Wildenhain, took part of the exhibition "five contemporary