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,
What Katy Did School (set in Hanover, New Hampshire); "What Katy Did Next", in which a new friend of Katy's takes her on a once-in-a-lifetime trip to Europe; "Clover", in which Katy is married and Clover accompanies her brother Phil to Colorado after he falls ill; and "In the High Valley", which shows the lives of a handful of young people living in the High Valley in Colorado, including Clover, Elsie and their husbands. What Katy Did What Katy Did is an 1872 children's book written by Sarah Chauncey Woolsey under her pen name Susan Coolidge. It follows the adventures of a twelve-year-old