Exactly on schedule, fourteen days and some hours after we had started off, we passed Pi Orionis. For long there had been no doubt in my mind that, whatever the explanation, our acceleration was holding steady. In the last few hours the star swept up to the brilliance of the sun, then faded again until it was no brighter than Venus. Venus! Our sun itself had been a mere dot in the rear telescope until the change in our course threw it out of the field of vision.
At sixty-five light-years, twenty-three days out, Beta Eridani was almost directly in our path for Rigel. Slightly less than a third of the distance to the midpoint, in over half the time. But our speed was still increasing 200 miles a second every second, almost four times the speed of light in an hour. Our watches went on with a not altogether disagreeable monotony.
There was no star to mark the middle of our journey. Only, toward the close of one of my watches, a blue light which I had never noticed came on beside the indicator dials, and I saw that we had covered 233 light-years, half the estimated distance to Rigel. The speed marker indicated 3975 times the speed of light. I wakened Garth.
"You could have done it yourself," he complained, sleepily, "but I suppose it's just as well."
He went over to the board and started warming up the rear gravity projector.
"We'll turn one off as the other goes on. Each take one control, and go a notch at a time." He began counting, "One, two, three ..."
On the twentieth count, my dial was down to zero, his up to maximum deceleration, and I pulled out my switch. Garth snapped sideways a lever on the indicators. Though nothing seemed to happen, I knew that the speed dial would creep backward, and the distance dial progress at a slower and slower rate. While I was trying to see the motion, Garth had gone back to bed. I turned again to the glass and looked out at Rigel, on the cross hairs, and Kappa Orionis, over to the left, and the great nebula reaching over a quarter of the view with its faint gaseous streamers.
And so we swept on through space, with Rigel a great blue glory ahead, and new stars, invisible at greater distances, flaring up in front of us and then fading into the background as we passed. For a long time we had been able to see that Rigel, as inferred from spectroscopic evidence, was a double star—a fainter, greener blue companion revolving with it around their common center of gravity. Beyond Kappa Orionis, three hundred light-years from the sun, the space between the two was quite evident. Beyond four hundred light-years, the brilliance of the vast star was so great that it dimmed all the other stars by comparison, and made the nebula seem a mere faint gauze. And yet even with this gradual change, our arrival was a surprise.