But now that the number of wires had swollen from hundreds to thousands, the overhead method had been outgrown.

Some streets in the larger cities had become black with wires.

Poles had risen to fifty feet in height, then sixty--seventy--eighty.

Finally the highest of all pole lines was built along West Street, New York--every pole a towering Norway pine, with its top ninety feet above the roadway, and carrying thirty cross-arms and three hundred wires.
From poles the wires soon overflowed to housetops, until in New York alone they had overspread eleven thousand roofs.

These roofs had to be kept in repair, and their chimneys were the deadly enemies of the iron wires.