Which German physicist developed a counter for detecting radioactive particles, later improved with Walther Müller in 1928?

In 1903, future president Franklin Roosevelt was elected to head which Harvard student newspaper? In 1909, Roald Amundsen hoped to be the first to reach which place, only to hear that Robert Peary claimed to have beat… By 1912, after the "scramble" for which continent, Britain and France controlled most of it? In 1912, which Native American athlete won both the Olympic decathlon and pentathlon? Radio station WSBT, launched by the South Bend Tribune in 1922, broadcasts from which state? In 1925, General John J. Pershing was sent to help resolve the Tacna-Arica border dispute between Peru and which countr… In 1933, which future "Yankee Clipper" hit safely in 61 straight games for the San Francisco Seals? In 1933, the mercantile agency founded by which man merged with competitor R.G. Dun & Company?