He became suspicious, would give up nothing without knowing just what he was doing, impose conditions that were perhaps unacceptable, wanted his mere assertions accepted as sufficient guarantee, and in any case asked for such a large sum of money on account before condescending to furnish the test of practical experiment that his overtures could not be entertained.
In the first place he had offered the fulgurator to France, and made known the nature of it to the commission appointed to pass upon his proposition.

The fulgurator was a sort of auto-propulsive engine, of peculiar construction, charged with an explosive composed of new substances and which only produced its effect under the action of a deflagrator that was also new.
When this engine, no matter in what way it was launched, exploded, not on striking the object aimed at, but several hundred yards from it, its action upon the atmospheric strata was so terrific that any construction, warship or floating battery, within a zone of twelve thousand square yards, would be blown to atoms.

This was the principle of the shell launched by the Zalinski pneumatic gun with which experiments had already been made at that epoch, but its results were multiplied at least a hundred-fold.
If, therefore, Thomas Roch's invention possessed this power, it assured the offensive and defensive superiority of his native country.
But might not the inventor be exaggerating, notwithstanding that the tests of other engines he had conceived had proved incontestably that they were all he had claimed them to be?
This, experiment could alone show, and it was precisely here where the rub came in.

Roch would not agree to experiment until the millions at which he valued his fulgurator had first been paid to him.
It is certain that a sort of disequilibrium had then occurred in his mental faculties.

It was felt that he was developing a condition of mind that would gradually lead to definite madness.