But if he had expected the American to show any trepidation as a result of his threats, he soon found out his mistake. Edestone’s reply was as insouciant as if he had been merely commenting on the weather.

“Really, this is quite interesting, Count von Hemelstein,” he said. “I might almost call you a man after my own heart. That bottle trick is so simple and yet effective that I, as an inventor, cannot help but compliment you. I am wondering just what chemical you have employed. There are of course a dozen or more that would answer your purpose; but as their action varies greatly in the effect upon the victim, I am naturally curious.”

“Does that mean that you are about to decline my offer?” demanded the Count sharply. “Have a care, Mr. Edestone. I am not merely trying to frighten you, as you may suppose. The facts are just as I have stated them, and I shall not hesitate to——”

“Assuredly, my dear Count,” Edestone broke in. “I have never doubted that for a moment. Nor am I going to refuse your proposition—that is, not definitely. Instead, I have been so pleased by the charming manner in which you have presented this little matter that I desire to submit a counter-proposition. Only, I must beg you to urge your modest friend with the weak eyes out there at the switchboard to be a little careful with that wire. Judging from the atmosphere in this booth, his bottle has been leaking for some time.”

“Come, come, Mr. Edestone.” The Count’s voice rose nervously, showing the strain under which he was labouring. “I have already told you that this is no joke. If it is your game to play for time, in the hope that some one may come to release you, or that you may discover the manner in which the bottle is secreted, you are going to be disappointed. I must do my work quickly. If I do not have your answer at once, I will give the signal and take your instrument away from you by force.”

“It is not time I want, but air.” Edestone gave a little gasp. “You yourself have spent more time than I, with your kind explanations as to how I may avoid what would be to me a most distressing accident. However, since celerity is what you want, I hasten to say that I have not my instrument, nor indeed any instrument with me.”

“Not with you?” snapped the Prussian angrily. “Where is it, then?”

“Ah! That is my counter-proposition. Count von Hemelstein, if I promise to tell you, on my word of honour, where you may find this instrument of mine that contains the entire secret of my invention—and it is near at hand where, if you are a brave man, you can easily get it,—if I do this, will you, on your side, give me your word as a gentleman, that you will immediately open this booth?

“I may add,” he went on, as von Hemelstein seemed to hesitate, “that this is my last and only proposition, and you can take that or nothing. I will die here in this box before I will sell my invention to any European Government; but you may have it as a free gift, Count, if you have the nerve to go after it. There is a challenge to your boasted Prussian valour! Are you a sport, Count von Hemelstein, or are you not?”

Von Hemelstein wavered no longer. From what Edestone told him, he argued that the inventor must have left his instrument with some of his subordinates, probably Black and Stanton, and relied upon them to protect it; and it stung him to think that the American should believe a German officer would falter at such odds—a couple of electricians, mere Yankee artisans.