Magnetic Storage. Piano wire, an electromagnet and a microphone. This was all the Danish inventor Valdemar Poulsen (1869-1942) needed in 1898 to create the telegraphone or wire recorder â the first known device capable of recording sound magnetically.agnetic Storage. Piano wire, an electromagnet and a microphone. This was all the Danish inventor Valdemar Poulsen (1869-1942) needed in 1898 to create the telegraphone or wire recorder â the first known device capable of recording sound magnetically.
And as of 2016, there are about 2.3 million home-schooled students in the United States (Brian, 2016). The studies found that of these children, 83 percent were White, 5 percent were Black, 7 percent were Hispanic, and 2 percent were Asian or Pacific Islander.
U.S. Cities are Home to 62.7 Percent of the U.S. Population, but Comprise Just 3.5 Percent of Land Area. A majority of the U.S. population lives in incorporated places or cities, although these areas only make up a small fraction of the U.S. land area, according to a new report released today by the U.S. Census Bureau. The percentage of the population living in cities in 2013 was highest in the Midwest and West at 71.2 percent and 76.4 percent, respectively.