adly,
"with frequent blow-outs, vortices, laterals, etc."

Still the clear dark holds up unblemished. The only warning is the
electric skin-tension (I feel as though I were a lace-maker's pillow)
and an irritability which the gibbering of the General Communicator
increases almost to hysteria.

We have made eight thousand feet since we pithed the tramp and our
turbines are giving us an honest two hundred and ten knots.

Very far to the west an elongated blur of red, low down, shows us the
North Banks Mark Boat. There are specks of fire round her rising and
falling--bewildered planets about an unstable sun--helpless shipping
hanging on to her light for company's sake. No wonder she could not quit
station.

She warns us to look out for the backwash of the bad vortex in which
(her beam shows it) she is even now reeling.

The pits of gloom about us begin to fill with very faintly luminous
films--wreathing and uneasy shapes. One forms itself into a globe of
pale flame that waits shivering with eagerness till we sweep by. It
leaps monstrously across the blackness, alights on the precise tip of
our nose, pirouettes there an instant, and swings off. Our roaring bow
sinks as though that light were lead--sinks and recovers to lurch and
stumble again beneath the next blow-out. Tim's fingers on the lift-shunt
strike chords of numbers--1:4:7:--2:4:6:--7:5:3, and so on; for he is
running by his tanks only, lifting or lowering her against the uneasy
air. All three engines are at work, for the sooner we have skated over
this thin ice the better. Higher we dare not go. The whole upper vault
is charged with pale krypton vapours, which our skin friction may
excite to unholy manifestations. Between the upper and the lower
levels--5,000, and 7,000, hints the Mark Boat--we may perhaps bolt
through if.... Our bow clothes itself in blue flame and falls like a
sword. No human skill can keep pace with the changing tensions. A vortex
has us by the beak and we dive down a two-thousand-foot slant at an
angle (the dip-dial and my bouncing body record it) of thirty-five. Our
turbines scream shrilly; the propellers cannot bite on the thin air; Tim
shunts the lift out of five tanks at once and by sheer weight drives her
bulletwise through the maelstrom till she cushions with a jar on an
up-gust, three thousand feet below.

"_Now_ we've done it," says George in my ear. "Our skin-friction that
last slide, has played Old Harry with the tensions! Loo