The ocean of air is just as real as any ocean of water; it has its currents and tides and its air-falls, similar to waterfalls, where air pours from a higher to a lower level. It is the lay of the land below that causes the differences in the vast ocean of atmosphere. Mountains, forests, valleys, all produce their own peculiar currents and cross currents in the aerial expanse above. Over hills, the air currents are deflected upwards. Over great flat tablelands, the air flows downward over the edges in vast Niagaras of air.
Weatherman Harrison had his air map, America of the Air, all wavy lines and curves and whorls.
From observation posts, on land and sea, all over the world, weather news is continually radioed to the United States Weather Bureau. From this mass of information, the Bureau continually computes and makes deductions and predicts impending weather conditions—which it radios back out into the ether for the safety of ships of both sea and air.
Thus a far-flung outpost wirelesses: “Storm sweeping southwest from Labrador at hundred and fifty miles an hour.”
Knowing its intensity, its area, and its initial speed, weather chiefs can tell that the storm will reach Toronto in so many hours, and the Mississippi Valley in so many more hours. Storm warnings tap through the air, radio speeds the word in all directions. In consequence, a mail plane for the West dips south in its itinerary to avoid nasty weather; shipping on the Great Lakes goes into dock or heads for the safety of open water; a mammoth dirigible changes its course to circle around a hail-and-wind-tortured sector of the ocean of air.
Between his hours of standing watch at the radio, Lee turned with delighted eyes to the mosaic of rivers, cities, forests and farms spread beneath the ship. Radiograms, together with the great wall map, helped him identify the cities and the scenic wonders over which they passed.
They swept above Toledo and the smokestacks of Detroit. In splendid spectacle, the Great Lakes rippled their waters beneath them in the gleaming sun.
“Well, well, Lee,” Captain Jan came down from the hull-storage section into the navigation car, bringing out for display one of the fur-lined sleeping bags and a snow knife, “how’s traveling? What do you think of your first ride in a dirigible?”
“Fine!” said Lee. “Only I might as well be sitting out on the front porch back in King’s Cove, so far as any motion can be felt. I can’t tell I’m moving until I happen to look down and glimpse cities and lakes swishing by at considerably over a mile a minute.”
“Um—yes, this thing rides a pretty even keel. Not much dipping and diving so far. And now take a look at these.” Captain Jan spread out his armful. “No matter whether it may seem cumbersome or not, a sleeping bag and one of these snow knives for cutting a wind-break out of a drift, is what every man must carry if he goes off from the ship any way at all after we land in the ice country. It’s a safety rule that I’m laying down.”