General Merton was silent now.
"Carnes, let me have that map," went on the doctor. When the detective had unrolled a map of the United States on Colonel Wesley's table, Dr. Bird continued, pointing to the map as he spoke.
"On this map," he said, "is plotted the deficiency in rainfall for the past year, from every reporting station in the United States. These red lines divide the country into areas of equal deficiency. The area most affected, as you can see, is longer east and west, than it is north and south. It is worst in the east, in fact in this very neighborhood. Even a casual glance at the map will show you that the center of the drought area, from an intensity standpoint, lies in Maryland, a few miles south of here."
"In fact, just about where those two planes went down," added Carnes.
"Precisely, old dear. That was why we went over that section with the fleet. Now, gentlemen, note a few other things about this drought. The areas of drought follow roughly the great waterways, the Ohio and the Potomac valleys being especially affected. In other words, the drought follows the normal air currents from this point. If something were to be added to the air which would tend to prevent rain, it would in time drift, just as the drought areas have drifted."
General Merton and Colonel Wesley bent over the map.
"I believe you're right, Doctor," admitted the general.
"Thank you. The President was convinced that I was before he placed the First Air Division under my orders. Frankly, that search was the real object of assembling the fleet. The maneuvers are a mere blind."
General Merton colored slightly.