Abstract: The liquid agitator is of the type used in stirring water containing small particles of suspended matter to cause the particles to come together and form agglomerations (e.g., flocs) which will settle faster than the individual small particles. The agitator includes a paddle having pale elements and each of the pale elements has a predetermined shape, size and disposition so that said paddle produces a substantially uniform velocity gradient in the water being agitated when the paddle is rotated. The uniform velocity gradient developed will provide uniform agitation of the water to obtain uniform flocculation throughout the agitated volume even though the linear velocity of various portions of the paddle will be different depending on the radial distance of that portion from the vertical axis. Another embodiment utilizes a second paddle wherein the pale elements project between the pale elements of the first paddle, said second paddle can be stationary or counter rotated with reference to the first paddle.