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.
The Numbers. The percentage of American grandchildren being raised by one or more grandparents in homes without parents present has risen over the past few decades. Whereas in 1991, U.S. Census Bureau figures show that about 1.7 percent of children in the U.S. lived in such home environments, that number has risen to 2.5 percent in 2009.