can you quote me when it's shown that snowball is more intelligent than napoleon? Animal farm

From the text:

Napoleon was a large, rather fierce-looking Berkshire boar, the only Berkshire on the farm, not much of a talker, but with a reputation for getting his own way. Snowball was a more vivacious pig than Napoleon, quicker in speech and more inventive, but was not considered to have the same depth of character.

Napoleon sent for pots of black and white paint and led the way down to the five-barred gate that gave on to the main road. Then Snowball (for it was Snowball who was best at writing) took a brush between the two knuckles of his trotter, painted out MANOR FARM from the top bar of the gate and in its place painted ANIMAL FARM.