An arc between carbons of equal diameter placed parallel to each other and spaced a small distance apart operates automatically on alternating current and the carbons burn down equally. When supplied with direct current the positive carbon is consumed at a rate approximately twice as great as that of the negative. Therefore to operate the ordinary parallel carbon arc on direct current some provision must be made to move the positive carbon forward, or a larger carbon must be used on the positive side of the circuit.
Proceedings of the Iowa Academy of Science
©1929 Iowa Academy of Science, Inc.
Spinney, L. B.
"A Parallel Carbon Arc for Direct Current,"
Proceedings of the Iowa Academy of Science, 36(1), 302-303.
Available at: https://scholarworks.uni.edu/pias/vol36/iss1/88