To the few who would have maintained that the document should not be taken seriously, an immense majority would have responded.

"This letter has not the style nor the spirit of a jester.

Only one man could have written it; and that is the inventor of this unapproachable machine." To most people this conclusion seemed indisputable owing to a curious state of mind easily explainable.

For all the strange facts of which the key had hitherto been lacking, this letter furnished an explanation.

The theory now almost universally accepted was as follows.