If it had been necessary to transfer this tremendous quantity of material from place to place by hand the cost would have been too great. Edison, therefore, designed an original and ingenious system of mechanical belt conveyors that would automatically receive and discharge their loads at appointed places in the works, covering about a mile in transit. They went up and down, winding in and out, turning corners, delivering material from one bin to another, making a number of loops in the drying-oven, filling up bins, and passing on to the next one when full. In fact, these conveyors in automatic action seemed to play their part with human intelligence.
We have been able to take only a passing glance at the great results achieved by Edison in his nine years' work on this remarkable plant—a work deserving of most serious study. The story would be incomplete, however, if we did not mention his labors on putting the fine ore in the form of solid briquettes.
When the separated iron was first put on the market it was found that it could not be used in that form in the furnaces. Edison was therefore obliged to devise some other means to make it available. After a long series of experiments he found a way of putting it into the form of small, solid briquettes. These answered the purpose exactly.
This called for a line of new machinery, which he had to invent to carry out the plan. When this was completed, the great rocks went in at one end of the works and a stream of briquettes poured out of the other end, being made by each briquetting machine at the rate of sixty per minute.
Thus, with never-failing persistence, infinite patience, intense thought and hard work, Edison met and conquered, one by one, the difficulties that had confronted him. Furnace trials of his briquettes proved that they were even better than had been anticipated. He had received some large orders for them and was shipping them regularly. Everything was bright and promising, when there came a fatal blow.
The discovery of rich Bessemer ore in the Mesaba range of mountains in Minnesota a few years before had been followed by the opening of the mines there about this time. As this rich ore could be sold for three dollars and fifty cents per ton, as against six dollars and fifty cents per ton for Edison's briquettes, his great enterprise must be abandoned at the very moment of success.
It was a sad blow to Edison's hopes. He had spent nine years of hard work and about two millions of his own money in the great work that had thus been brought to nought through no fault of his. The project had lain close to his heart and ambition, indeed he had put aside almost all other work and inventions for a while.
For five of the nine years he had lived and worked steadily at Edison (the name of the place where the works were located), leaving there only on Saturday night to spend Sunday at his home in Orange, and returning to the plant by an early train on Monday morning. Life at Edison was of the simple kind—work, meals, and a few hours' sleep day by day, but Mr. Edison often says he never felt better than he did during those five years.
After careful investigations and calculations it was decided to close the plant. Mr. W. S. Mallory, his close associate during those years of the concentrating work, says: "The plant was heavily in debt, and, as Mr. Edison and I rode on the train to Orange, plans were discussed as to how to make enough money to pay off the debt. Mr. Edison stated most positively that no company with which he had been personally actively connected had ever failed to pay its debts, and he did not propose to have the concentrating company any exception.