Tweak seventies sample

In the seventies sample, the triangular ticks have their endpoints scaled to the shape of the clock face. Try computing the endpoints of the baseline so it touches the second ticks, then subtract a constant distance from both x coordinates. Then the slope of the baseline should match the perceived slope of the ticks better. The way we do it now, it is matching a tighter curve, and that may be why it looks out of whack without magic constant tweaks.