If a cylinder move uniformly forward in the direction of its length, the resistance made thereto is not at all changed by augmenting or diminishing that length; and is therefore the same with the resistance of a circle, described with the same diameter, and moving forward with the same velocity in the direction of a right line perpendicular to its plane.
For the sides are not at all opposed to the motion; and a cylinder becomes a circle when its length is diminished in infinitum.