Gear but RTX is ON

Mechanism 1: Spur-gears

Mechanism 2: Bevel-gears. Those of equal diameters are termed “miter-gears.

Mechanism 3: Worm or endless screw and a worm-wheel.

Mechanism 4: An internally toothed spur-gear and pinion. With ordinary spur-gears the direction of rotation is opposite; but with the internally toothed gear, the two rotate in the same direction; and with the same strength of tooth the gears are capable of transmitting greater force, because more teeth are engaged.

Mechanism 5: Sun-and-planet motion. The spur-gear to the right, called the planet-gear, is tied to the center of the other, or sun-gear, by an arm which preserves a constant distance between their centers. This was used as a substitute for the crank in a steam engine by James Watt, after the use of the crank had been patented by another party. Each revolution of the planet-gear, which is rigidly attached to the connecting-rod, gives two to the sun-gear, which is keyed to the fly-wheel shaft.

Mechanism 6: Best explanation of these gears in the comments wins.

Mechanism 7: Circular into rectilinear motion, or vice versa, by means of rack and pinion.

Mechanism 8: An “epicyclic train.” Any train of gearing the axes of the wheels of which revolve around a common center is properly known by this name. The wheel at one end of such a train, if not those at both ends, is always concentric with the revolving frame.

0:00 Mechanism 1
0:11 Mechanism 2
0:21 Mechanism 3
0:31 Mechanism 4
0:43 Mechanism 5
0:57 Mechanism 6
1:08 Mechanism 7
1:20 Mechanism 8