"Got it," he said shakily. He moved the 'Tee' bar very gently until the phanobeacon was centered on the screen. Or, rather, almost centered. It moved in jerky little circles like the sights of a rifle in the hands of a tyro.
"Fine. You're doing well with strange equipment. Now, on the panel you will find a switch marked 'Co-ordinates.' It will be set on 'Rectangular' and you must flip it to 'Polar'."
The switch changed the cross-hair pattern of the viewpanel from the horizontal and vertical calibrations to a circular pattern with only the main center hairlines remaining. Angle-lines radiated out from the center, crossing the circles.
"Now, Dusty, inspect the radius-line marked G-705. All the way around. Do you see a winking star?"
"No."
"Um. I was hoping we could do it the easy way. The sealed course-plan is not too clear, for which I don't blame Transgalactic. All right. We'll have to do it the hard way. Move the phanobeacon down until it is almost on the lower edge of the viewpanel. Now flip the 'Co-ordinates' switch to the left, leaving it in the bottom position marked 'Polar.' You'll find that the toggle has an 'H' type pattern of motion, laid flat-wise."
The polar co-ordinates disappeared completely from the center of the viewpanel and centered around the phanobeacon spot. They made larger and larger arcs as the circles approached the top of the panel.
"Now this is going to be tricky. You must twist the 'Tee' bar slowly and let the ship rotate, but you must also move it so that the phanobeacon stays near its present off-center position. But before you do this, let me explain what you are actually doing in space. Picture a needle-shaped spacecraft with a line along the axis running out before the ship, marking the line of drive, or direction. At some distance from the line lies a spot which denotes the phanobeacon. Somewhere out beyond, there is another spot that must be sighted within the confines of an angle not greater than the angle made between the point of aim, or line of drive, and the imaginary line running from the nose of the ship to the phanobeacon. So you must cause the ship to rotate on a false axis, making the line of flight describe a cone of revolution with the phanobeacon on the axis of the cone. Now, go ahead and try."
"Okay." Dusty moved the 'Tee' bar and the stars moved in jaggledy little scallops along a greater arc. The center of the beacon held the polar lines, but they moved with the stars and with the beacon. It made Dusty dizzy and his eyes began to ache. "What am I looking for?" he asked plaintively.
"Look along the outer circles for a winking st—"