"A montgolfier?" asked Marche, curiously.
"Oh, pooh! The idea! No, it is like other balloons, except that--well--there is needed merely a handful of silvery dust--to which you touch a drop of water--piff! puff! c'est fini! The balloon is filled."
"And what is this silvery dust?" he asked, laughing.
"Voilà! Do you not wish you knew? I--Lorraine de Nesville--I know! It is a secret. If the time ever should come--in case of war, for instance--my father will give the secret to France--freely--without recompense--a secret that all the nations of Europe could not buy! Now, don't you wish you knew, monsieur?"
"And you know?"
"Yes," she said, with a tantalizing toss of her head.
"Then you'd better look out," he laughed; "if European nations get wind of this they might kidnap you."
"They know it already," she said, seriously. "Austria, Spain, Portugal, and Russia have sent agents to my father--as though he bought and sold the welfare of his country!"
"And that map-making fellow this morning--do you suppose he might have been hanging about after that sort of thing--trying to pry and pick up some scrap of information?"
"I don't know," she said, quietly; "I only saw him making maps. Listen! there are two secrets that my father possesses, and they are both in writing. I do not know where he keeps them, but I know what they are. Shall I tell you? Then listen--I shall whisper. One is the chemical formula for the silvery dust, the gas of which can fill a balloon in five seconds. The other is--you will be astonished--the plan for a navigable balloon!"
"Has he tried it?"
"A dozen times. I went up twice. It steers like a ship."
"Do people know this, too?"
"Germany does. Once we sailed, papa and I, up over our forest and across the country to the German frontier. We were not very high; we could see the soldiers at the custom-house, and they saw us, and--would you believe it?--they fired their horrid guns at us--pop! pop! pop! But we were too quick; we simply sailed back again against the very air-currents that brought us. One bullet made a hole in the silk, but we didn't come down. Papa says a dozen bullets cannot bring a balloon down, even when they pierce the silk, because the air-pressure is great enough to keep the gas in. But he says that if they fire a shell, that is what is to be dreaded, for the gas, once aflame!--that ends all. Dear me! we talk a great deal of war--you and I. It is time for me to go."
They rose in the moonlight; he gave her back her fan. For a full minute they stood silent, facing each other. She broke a lily from its stem, and drew it out of the cluster at her breast. She did not offer it, but he knew it was his, and he took it.