How does a pole appear when one end is placed in the water?
It appears to be bent where it meets the surface of the water.
How does the part of the rod under water appear?
The part under the water appears to be raised up, as may be seen in [Fig. 7].
How does the bottom of a pond or stream of water appear?
It appears to be raised up, and the water does not seem so deep as it really is.
Why is this the case?
Because the light from the bottom of the pond is refracted or bent at the surface of the water; hence, the bottom appears to be raised up.
How much does the bottom of a pond or stream of water seem to be raised up?
About one-third of the depth of the water.