smit 800
words per minute between New York and Chicago.

It was proposed to string a steel-copper wire, the copper on which was
to weigh 500 lb. to the mile.

When complete, the wire was rather larger than No. 3, English gauge, but
varied in diameter, some being as large as No. 1, and it averaged 525
lb. of copper per mile and = 1.5 ohms. The surface of this wire was,
however, large.

Dr. Muirhead estimated its static capacity at about 10 M.F., which
subsequent tests proved to be nearly correct.

It will be understood that this static capacity stood in the way of fast
transmission.

Resistance and static capacity are the two factors that determine speed
of signaling.

The duration of the variable state is in proportion to the square of the
length of the conductor, so that the difficulties increase very greatly
as the wire is extended beyond ordinary limits. According to Prescott,
"The duration of the variable condition in a wire of 500 miles is
250,000 times as long as in a wire of 1 mile."

In other words, a long line _retains a charge_, and time must be allowed
for at least a falling off of the charge to a point indicated by the
receiving instrument as zero.

In the construction of the line care was taken to insure the _lowest
possible resistance_ through the circuit, even to the furnishing of the
river cables with conductors weighing 500 lb. per mile.

Ground wires were placed on every tenth pole.

When the first 100 miles of wire had been strung, I was much encouraged
to find that we could telegraph without any difficulty past the average
provincial "ground," provided the terminal grounds were good.

When the western end of this remarkable wire reached Olean, N.Y., 400
miles from New York, my assistant, Mr. S.K. Dingle, proceeded to that
town with a receiving instrument, and we made the first test.

I found that 800 words, or 20,000 impulses, per minute, could be
transmitted in Morse characters over that circuit _without compensation_
for static.

In other words, the old Bain method was competent to telegraph 800 words
per minute on the 400 miles of 1.5 ohm wire.

The trouble began, however, when the wire reached Cleveland, O., about
700 miles from New York.

Upon making a test at Cleveland, I found the signals made a continuous
black line upon the chemical paper. I then placed both ends of the wire
to earth through 3,000 ohms resistance, and introduced a small auxiliary
battery between the chemi