Dr. Paul Israel

If the signal had to go further, then an operator had to retransmit it.

And so what people began to develop were repeaters.

And Edison had a lot of designs for repeaters, including one that was actually featured in a book on telegraphy as a repeater that could be set up in an emergency situation.

And then he also was experimenting on things like ways to send more than one message over a single line.

And Edison moves from the Midwest to Boston, where he begins to work on his first important inventions, in particular a stock printer.

that was used to report gold prices.

This, along with his double transmitter, bring him to New York, where he's involved with the Golden Stock Telegraph Company and develops improvements in stock ticker technology used not just on the stock exchange,

but all market exchanges, gold, silver, produce, oil, cotton.

This connects him up to Western Union, in part because he's also working on ways of sending two messages at the same time, and he invents something called the quadruplex, which allows four messages, two in each direction.

And this and other inventions of the telegraph industry lead Edison to begin to develop a small laboratory in Newark.

And by the end of the year, 1875, he decides that he wants to get his family out of the city, which is becoming increasingly polluted.

So he finds some land just off the rail line between Newark and Philadelphia in central New Jersey.

And that's where he sets up this new laboratory.

It's a wooden building.

It has a machine shop in the bottom half of the building.

Upstairs is an electrical and chemical lab.

And by this time, he is working for Western Union.

He convinces the company to provide him with $100 a week to help support the work of the machine shop and the machinists that are there.

He only has five people, three machinists.

It tells you how important the machine shop is for iterating designs.