That resistance must be overcome by power expended for the purpose.

That the base of the bicycle is practically without width, and is usually about from forty-two to forty-four inches long.

That the direction of the base may be changed at will within certain limits.

That the bicycle will fall unless prevented from doing so.

That to prevent a bicycle from falling, or to maintain a bicycle on its base, it is necessary to balance it.

That the constant effort to maintain the bicycle upright upon its base is on account of the motion of the different opposing forces.

The bicycle is constructed to overcome the resisting forces in different ways, supplying as many forces as can be made available to accomplish a particular purpose, permitting a certain choice and discrimination in the matter.

The bicycle has one weight-carrying wheel and a frame and a pivoted wheel. The driving power is applied to the weight-carrying wheel, and the steering is done with the pivoted wheel. The bicycle remains upright because several forces co-operate to enable it to maintain its plane, change direction, and overcome certain resisting and opposing forces.

A bicyclist is propelled at a sufficient velocity to maintain the plane of movement. By altering the centre of gravity, inclining one way or the other, change of direction may be made.

The front or guiding wheel of the bicycle, being controlled by the different angles of resistance it presents to the surface it rotates upon, and not being immovably fixed, can pivot to a plane corresponding to a plane of least resistance. After a little momentum is attained, a bicycle will maintain its speed with but little assistance of power, unless it is accidentally obstructed, or an increase of grade requires an increase of power.