Had I used the apergy only to drive me directly outward from the Sun, I should move under the impulse derived from the Earth about 1,600,000 miles a day, or 72 millions of miles in forty-five days, in the direction common to the two planets.
The effect of the constantly widening orbit would be much as if the whole motion took place on one midway between those of the Earth and Mars, say 120 millions of miles from the Sun.

The arc described on this orbit would be equivalent to 86 millions of miles on that of Mars.

The entire arc of his orbit between the point opposite to that occupied by the Earth when I started and the point of opposition--the entire distance I had to gain as measured along his path--was about 116 millions of miles; so that, trusting to the terrestrial impulse alone, I should be some 30 millions behindhand at the critical moment.
The apergic force must make up for this loss of ground, while driving me in a direction, so to speak, at right angles with that of the orbit, or along its radius, straight outward from the Sun, forty odd millions of miles in the same time.

If I succeeded in this, I should reach the orbit of Mars at the point and at the moment of opposition, and should attain Mars himself.

But in this I might fail, and I should then find myself under the sole influence of the Sun's attraction; able indeed to resist it, able gradually to steer in any direction away from it, but hardly able to overtake a planet that should lie far out of my line of advance or retreat, while moving at full speed away from me.