"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.
"Symbol of France," she whispered.
"Symbol of Lorraine," he said, aloud.
A deep boom, sullen as summer thunder, shook the echoes awake among the shrouded hills, rolling, reverberating, resounding, until the echoes carried it on from valley to valley, off into the world of shadows.