Apple Final Cut Pro 7 - Manual (Page 1161)

Timeline speed indicators show you the relative playback speed of clips in your sequence.
For example, suppose you have a 10-second clip in your sequence. At normal, 100 percent
speed, the Timeline speed indicators are evenly spaced, indicating that your clip is playing
forward at a constant speed.
At normal speed, the
speed indicators are
evenly spaced.
If you make a speed change to slow down a clip (setting the clip’s speed to 50 percent,
for example), the speed indicators are spaced farther apart as the clip grows longer,
indicating slower playback. If you speed up a clip (changing the speed to 200 percent,
for example), the speed indicators move closer together as the clip becomes shorter,
indicating faster playback.
Slow speed Fast speed
1161 Chapter 69 Changing Clip Speed