This time an old slide projector lens was used. This pyramid also belongs to the sweating fountain type since the depression of the saucer will hold some water even when the saucer becomes totally dry.
The pyramid will remain wet, drying eventually from the top down.
It is called the Oculus Pyramid because, like the Pantheon in Rome, the structure is wet on the outside and dry below the oculus.
Refer to the ‘concrete for the home’ category for tips on concrete, tools and molds.