For weeks we had been warned that the Germans were going to use asphyxiating gasses against us, but no one had ever dreamed that they would be so inhuman as to use gas that would kill, but they had done so, for the Turcos told us that many of their men had fallen dead where they stood.

Two men who were standing under cover of the broken wall of the windmill crumpled up like green leaves in a forest fire. They were done for. They were giving us a double "curtain of fire" as well as the death dealing gasses. A piece of the same shell struck Lieutenant Shoenberger, my signalling officer, who stood close beside me, and he fell.

He was put into a communication trench from which he directed his men. The line held against the first attack. Although the Germans broke through in several places they were driven back and paid a fearful price for their daring. The gasses rolled to the supporting trenches and made life unbearable. The pungent smell was awful.

It is popularly held that abundance of fresh air is necessary to supply the oxygen for breathing and that carbon dioxide is a poison. Both are mistakes. The amount of oxygen normally in the air is about 20 per cent. Of carbon dioxide there is normally three hundredths of one per cent. During breathing these gasses are exchanged in about equal volume.

We'll be cooled by conduction and convection." As the others got the suits ready, he lowered the ship gently to the snowy ground. It sank into nearly ten feet of snow. He turned on the powerful searchlight, and swept it around the ship. Under the warm beams, the frozen gasses evaporated, and in a few moments he had cleared the area around the ship. Morey and the others came back with their suits.

It was of silk, prepared with gutta percha, a substance impermeable by acids or gasses; and its volume, which was three thousand cubic yards, enabled it to ascend to the loftiest heights. The day of the ascent was that of the great September fair, which attracts so many people to Frankfort.

Wade, as chemist, tested the air while the others readied the distillation and air condensation apparatus. By the time they had finished, Wade was ready with his report. "Air pressure about 20 psi at the surface; temperature around ninety-five Fahrenheit. Composition: eighteen percent oxygen, seventy-five percent nitrogen, four-tenths of one percent carbon dioxide, residue inert gasses.

In the lines of the defenders dropped huge bombs that sent up dense vapors the deadly gasses of the foe but they caused little harm, for the French were protected. Now and then a man fell, however; perhaps he had failed to adjust his helmet properly, or perhaps it was not perfect. But for the most part the gas bombs had little effect.

All the German batteries were concentrated on our parapets and the trenches held by our regiment. Pandemonium reigned along the front line of trenches. The Germans followed up their gasses again with intense rifle and machine gun fire. Up and down along the parapets of the redoubts the shells kept dropping, throwing up huge pyramids of black smoke fifty feet in the air.

The air was faintly yellow, the sky was yellow with a greenish cast, and the clouds were green-gray. No human had ever set foot on the surface, or breathed the air, of Niflheim. To have done so would have been instant death; the air was a mixture of free fluorine and fluoride gasses, the soil was metallic fluorides, damp with acid rains, and the river was pure hydrofluoric acid.