attracted her attention. This proved to be chart or map mounted at
either end on short rollers. As the girl watched it, she perceived
that it moved slowly. A red line was drawn across the map and
hovering over this was the tip of a metal pointer. A compass and a
watch were mounted at one side of the chart case.

Ethel watched the chart creep back on its rollers and reasoned that
the pointer indicated the location of the aeroplane. She wondered
how the movement of the chart was regulated with that of the plane.
Finally she decided to ask Komoru.

"By the landmarks and the time," he said. "Do you see that blue
coming in on the northeast corner of the map?"

"Yes."

"Well, watch it."

After a few minutes of waiting the words "_Gulf of Mexico_" rolled
out upon the chart. "Why, that can't be," said Ethel, "we just left
the Pacific Ocean."

"But we have crossed the Isthmus of Tehauntepec," replied Komoru;
"it is only a hundred miles wide."

His companion looked over the side of the car and to the front and.
to the right, she could see by the perfectly flat horizon that they
were approaching water.

"The map is unrolling too fast," said Komoru, as the pointer stood