ads, like ropes bent around the lower end of the lake. The night
was too dark to see it long. The hundreds of huge oil tanks of Whiting
had now disappeared, and I could see only the flaming tops of the iron
furnaces of South Chicago. Suddenly they went out in an instant, as if a
thick fog had smothered them, and there was a long minute of pale mist;
and then suddenly a bright blue sky, the twinkling stars and a veil of
grey shutting off all view of the Earth.

"We have passed through the clouds," said the doctor cheerily. "What
does the barometer register?"

I looked, and was astonished to see the mercury down to fifteen. I asked
him if he thought the barometer might be broken.

"No, that is quite right," he replied. "That is half the surface
pressure, which shows that we are two and a half miles high. I have four
batteries in, and we are going at a constantly increasing speed now."

I could easily believe it, for the wind howled around my compartment and
whistled over the rudder aperture in a most dismal way. Whenever the
rudder was changed, there was a new sound to the moaning. Still, as I
looked back at the clouds, I saw that no wind was moving them. It was
not wind, but only the air whistling as we rushed through it.

"Watch the barometer, and let me know the exact time when it registers
seven and a half inches," said the doctor. "We shall be five miles high
then, and we started at nine o'clock to a second."

I noted the rapidly sinking mercury and opened my watch. When it was
just at seven and a half, I looked at the watch, and it said half a
minute after nine. Knowing that could not be correct, I held it to my
ear and discovered it was stopped. I attempted to wind it, but found it
almost wound up.

"Something wrong with my watch, Doctor. You will have to look."

"Half a minute after nine, that can't be right!" he exclaimed. Then as
the truth flashed upon him he added,--

"There is the first thing I have overlooked! Our watch springs are
steel, and the magnetic currents affect them. It is strange I did not
think of that, for I knew a mariner's compass would be of no use to us
in steering on account of the currents. For that reason I have risen
above the clouds so as to steer by the stars. I am making for the North
Star yonder, now."

"We will have to get back to the same primitive methods of measuring
time," I put in. "Neither weight clocks nor spring clocks would have
been of any account. And an hour gl