tory was not all exactly alike. Some parts of it crumbled away
faster, leaving a pattern of baffles which acted like a maxim silencer
on a rifle, or like an automobile muffler. The baffles set up eddies in
the gas stream and produced exactly the effect of a rocket motor's
throat. But the baffles themselves crumbled and were flung astern, so
that the solid-fuel rockets had always the efficiency of gas-throated
rocket motors; and yet every bit of refractory was reaction-mass to be
hurled astern, and even the steel tubes melted and were hurled away with
a gain in acceleration to the ship. Every fraction of every ounce of
rocket mass was used for drive. No tanks or pumps or burners rode
deadhead after they ceased to be useful.

But solid-fuel rockets simply can't be made to burn with absolute
evenness as a team. Minute differences in burning-rates do tend to
cancel out. But now and again they reinforce each other and if
uncorrected will throw a ship off course. Gyros can't handle such
effects. So Joe had to watch his instruments and listen to the tinny
voice behind him and steer the ship against accidental wobblings as the
Earth fell away behind him.

He battled against the fatigue of continuing to live, and struggled with
gyros and steering jets to keep the ship on its hair-line course. He
panted heavily. The beating of his heart became such a heavy pounding
that it seemed that his whole body shook with it. He had to do
infinitely fine precision steering with hands that weighed pounds and
arms that weighed scores of pounds and a body that had an effective
weight of almost a quarter of a ton.

And this went on and went on and on for what seemed several centuries.

Then the voice in the speaker said thickly: "_Everything is in the
clear. In ten seconds you can release your rockets. Shall I count?_"

Joe panted, "Count!"

The mechanical voice said, "_Seven ... six ... five ... four ... three
... two ... one ... cut!_"

Joe pressed the release. The small, unburnt stubs of the take-off
rockets went hurtling off toward emptiness. They consumed themselves as
they went, and they attained an acceleration of fifty gravities once
they were relieved of all load but their own substance. They had to be
released lest one burn longer than another. It was also the only way to
stop acceleration by solid-fuel rockets. They couldn't be extinguished.
They had to be released.

From intolerably burdensome heaviness, there was abruptly n