# oil and water- The Archimides' law

I have a problem as on the topic, see the below.

First I added $25\hbox{cm}^3$ water in to a beaker. Then I added $2N$ oil onto it. But the level of the water was still $25\hbox{cm}^3$.

My problem is this. Archimedes' principle states that,

the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid.

So according to this situation the upward buoyant force by water should equal to the the weight of the oil due to the equilibrium. Also it should be same to the weight of the displaced water volume. But as the practical shows the displaced water volume is $0$.So the upward buoyant force should be 0. But according to the equilibrium the upward buoyant should be $2N$.

Where is the mistake?