Then increase slackened for many years, and was slowest between 1886 and 1891, when the addition was but 48,000 in five years.
The slowest speed is given by means of a tangent screw which is carried by a ball-bearing on the flange of the telescope sleeve, whilst its nut is double-jointed to a ring that encircles the flange of the heliometer-tube.
The pursuit of the French was ineffective, for Tourville persisted in keeping his ships in line of battle, which forced them to regulate their speed by the slowest among them.
Then, by an obvious law of kinematics, the angular motion round the earth would be most rapid at the point nearest the earth, that is at perigee, and slowest at the point most distant from the earth, that is at apogee.
With similar bevel-gear and rods the tangent screw is connected to the hand-wheel, 79, by which the observer communicates the fourth or slowest motion in position angle.