Having probably confused the reader’s mind sufficiently by this time to go on with the subject, I may say that another fact why the reasoning and formula in regard to the side-slip are not correct is that the same rule applied to the Rover does not in any way justify the results we find by experience. The slipping of the Rover is much more than it should be, in the light of any conclusion based on our formula; in fact, I believe the entire theory is, and always has been, an unmitigated blunder. A well-known correspondent, Mr. Gerald Stoney, has thrown a little light on the subject by an article in the _Irish Cyclist_, which, though death to one theory, sets up another still of dubious tenability. “SIDE-SLIPPING OF BICYCLES. “Mr. Gerald Stoney, in last week’s _Irish Cyclist_, adds the following to this interesting and important discussion. It will be noticed his deductions differ both from those of Mr. Lee and ourselves. “In a leader in _The Cyclist_ of November 28, the reason that low machines of the Kangaroo type slip more than the high Ordinary is referred to the pressure of the foot being low down, pushing the bottom of the wheel to one side more than in a high machine when it is high up. We should wish to point out that no such effect can take place so long as the pressure of the foot does not cause the machine to wabble; since, so long as there is no change in the velocity or direction of motion of the machine, the position, direction, or amount of internal forces, such as the pressure of the foot, do not affect the position, direction, or amount of external forces, such as the pressure of the wheel on the ground. This is one of the first great elementary principles of mechanics. The reason why a small bicycle has, in general, more tendency to slip sideways than one in which the rider is seated high up is, that if the wheel slips off a stone or down the side of a rut, the distance sideways to which the wheel will slip is independent of the size of the wheel, and depends on the size of the stone or rut, the state of the road, the speed the machine is going at, etc. But the amount by which the machine is inclined to the vertical from a given side-slip will depend on how high the centre of gravity is, and, therefore, on how high the rider is seated, and accordingly it will be less the higher the saddle is. Now, it is a theorem in mechanics, which we will ask the reader to assume, that the greater this inclination the greater the tendency of the wheel to go on slipping, when it has hopped off the rut, stone, etc., and, therefore, the higher the saddle the less side-slipping there will be in _similar machines_.’”