Sweetwater who had been so violently wheeled about in entering that he stood with his back to the curtain concealing the car, answered without hesitation.

“You have a device, entirely new so far as I can judge, by which this car can leap at once into space, hold its own in any direction, and alight again upon any given spot without shock to the machine or danger to the people controlling it.”

“Explain the device.”

“I will draw it.”

“You can?”

“As I see it.”

“As you see it!”

“Yes.  It’s a brilliant idea; I could never have conceived it.”

“You believe—­”

“I know.”

“Sit here.  Let’s see what you know.”

Sweetwater sat down at the table the other pointed out, and drawing forward a piece of paper, took up a pencil with an easy air.  Brotherson approached and stood at his shoulder.  He had taken up his pistol again, why he hardly knew, and as Sweetwater began his marks, his fingers tightened on its butt till they turned white in the murky lamplight.

“You see,” came in easy tones from the stooping draughtsman, “I have an imagination which only needs a slight fillip from a mind like yours to send it in the desired direction.  I shall not draw an exact reproduction of your idea, but I think you will see that I understand it very well.  How’s that for a start?”

Brotherson looked and hastily drew back.  He did not want the other to note his surprise.

“But that is a portion you never saw,” he loudly declared.

“No, but I saw this,” returned Sweetwater, working busily on some curves; “and these gave me the fillip I mentioned.  The rest came easily.”

Brotherson, in dread of his own anger, threw his pistol to the other end of the shed: 

“You knave!  You thief!” he furiously cried.

“How so?” asked Sweetwater smilingly, rising and looking him calmly in the face.  “A thief is one who appropriates another man’s goods, or, let us say, another man’s ideas.  I have appropriated nothing yet.  I’ve only shown you how easily I could do so.  Mr. Brotherson, take me in as your assistant.  I will be faithful to you, I swear it.  I want to see that machine go up.”

“For how many people have you drawn those lines?” thundered the inexorable voice.

“For nobody; not for myself even.  This is the first time they have left their hiding-place in my brain.”

“Can you swear to that?”

“I can and will, if you require it.  But you ought to believe my word, sir.  I am square as a die in all matters not connected —­well, not connected with my profession,” he smiled in a burst of that whimsical humour, which not even the seriousness of the moment could quite suppress.

“And what surety have I that you do not consider this very matter of mine as coming within the bounds you speak of?”

“None.  But you must trust me that far.”