Two cylinders in a uniform flow can attract each other when their separation distance is within the zones of the perturbed velocities of the cylinders. Enhanced perturbed velocity between cylinders causes lowered pressure by Bernoulli’s law. If the cylinders touch or the gap is very small, the flow will work to separate the cylinders. One result could be an oscillation. Two recent theoretical discussions of uniform and shear flows past a single cylinder helped spark the present prediction. No relevant experimental studies have been carried out so far.