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.
Private schools are generally free to determine their own curriculum and staffing policies, with voluntary accreditation available through independent regional accreditation authorities. About 87% of school-age children attend public schools, about 10% attend private schools, and more than 3% are homeschooled. Education is compulsory over an age range starting between five and eight and ending somewhere between ages sixteen and eighteen, depending on the state.