It seems like an early Mitchell postcard. The layout almost looks more like a
Detroit. Never had heard of the "wave motor" until seeing this card. An interesting, but failed concept.
The inventors were a pair of brothers named William and John Armstrong. The wave motor, an oscillating water column, was built inside the cliff. They had dug a thirty-five by six foot hole into the side of the cliff that ran to a level below low tide. From there another tunnel connected it with the ocean. The purpose was to get water up to the the scenic dirt road on the bluff that needed to be kept damp because of the dust that was kicked up by tourists..
Some more info on the wave motor here:
The wave motor was dismantled in 1910 because of improved street paving that made it unnecessary to water down the roads. One of the tunnels still remains in the cliffs to this day.