Factors that were not changed in the experiments, such as the width of the coagulum and weir height, could not be explicitly shown. This should be considered when using the relevant equations, whereas the other fails under certain conditions. Resistance and current pressure, bubbles, and movement of foams are also important.

1. Introduction
2. J. Newton has already dealt with the resistance of moving bodies in fluids (air) both theoretically and experimentally. He established that if F is the projection of the body on a plane perpendicular to the direction of movement, then the equation can be expressed as W = (J'F'v). This is essentially the momentum change of the fluid mass displaced in a unit of time. According to this view, the resistance of a humped disc would be the same whether its hollow side is turned towards or away from the direction of movement.