Duncan rather expected the princess to appear, as she had promised in case of open warfare; but either she did not consider the emergency had yet arisen or she had been prevented from acting as she wished.
“I won’t go without her, though,” he muttered, decidedly.
“Tell me,” said I, “what is your object in wanting to wait until to-morrow before escaping from here? I can’t see that another day will bring any better condition to our captivity, and it’s a settled fact that we can’t get the machine out of this enclosure, in any event.”
“Perhaps I ought to explain,” he began, and then paused for a long time, as if absorbed in deep thought.
“Take your time, Duncan,” I remarked, impatiently.
He did not notice the sarcasm, but my voice aroused him and he said:
“Perhaps you remember that I once told you I used a glycerine explosive of my own invention to prime the engines of this automobile. In starting, a tiny drop is fed into the cylinders to procure the air compression which furnishes the motive power.”
“I remember; go ahead.”
“The feeding chamber is supplied with enough of this explosive to run the machine a year or more,” he continued; “but when I made it, in my own laboratory, the apparatus required was so complicated and expensive that I decided to manufacture an extra supply, to use in other machines which I intended to build later.”
“I see.”