By Doug Criner

This subject is about as close that an electrical engineer can come to applying his expertise to the ruins of Pompeii.

Photo 1 - "Main Street"

First, imagine yourself an ancient boatman, 2000 years ago, walking down the "main drag" shown in Photo 1, leading toward the harbor/wharf area.  It is pitch dark, and you are heading back to your boat after an evening of vino and perhaps a visit to one of the brothels.  The basalt-paved street is wet and slippery.  Basalt, solidified lava rock, is very black, smooth, and hard.  One stumble, and you may fall and break your leg or crack open your head.  You need just a little light.

Photo 2 - Roadway Lighting Niches

The niches in the wall shown in Photo 2 are said to be places to mount torches or lamps to illuminate the street.  A cynic might suspect another use, e.g., pockets for beams, but there are other niches on similar buildings that are more convincing. Even with such illumination, the black, smooth basalt would show limited contrast and texture.  Walking in your slightly diminished state would still be treacherous.

Photo 3 - "Cat Eyes" Embedded in Pavement?

Roman ingenuity to the rescue:  Photo 3 shows white rocks, "cat eyes," embedded in the interstices between the basalt stones.  These would help improve the luminance of the street and provide some needed contrast.

Is there any credibility to this theory?

Photo 4 - "Cat Eyes" in a Modern Sorrento Sidewalk

While such "cat eyes" are seemingly unknown in the U.S., the concept is still applied in modern Italy.  Photo 4 shows a relatively new brick sidewalk in Sorrento with patterns of white which will be easily visible in the illumination of the street lamp visible between the first two trees on the right.  Q.E.D.

© Doug Criner, 2003