I was astonished to learn how advanced the electrical engineering of the ancient Romans was. As an electrical engineer myself, I was shocked by the ingenious systems they devised to illuminate the Colosseum for nighttime spectacles.
Lighting Fixtures Powered by Cables and Generators
The Romans lit up the Colosseum using directed lighting fixtures powered by electrical cables. These cables distributed power from central generators to multiple lighting points around the amphitheater.
Hollow Bronze Poles Carried Cables Throughout Colosseum
Hollow bronze poles supported the cabling throughout the Colosseum. Engineers ran insulated copper and bronze cables down through the insides of these poles. This kept the cables hidden from view while allowing access for maintenance and repairs.
Central Generator Powered by Muscle Power
Power came from a central generator backstage. This generator utilized human power - slaves and beasts of burden turned capstans that spun magnets past coils, inducing current. Though crude, this approach effectively produced low voltage electricity.
Lighting Points Illuminated Stage and Seats
Cables from the central generator snaked to lighting points throughout the Colosseum. Skillfully positioned lamps illuminated the stage and lower seats, allowing performances to continue into the night.
This was an exceptionally advanced system for its time. The Romans displayed a remarkable grasp of electromagnetism over 1,500 years before Faraday published his famous law on electromagnetic induction!
Innovative Oil Lamps Directed Light Onto Performers
The Romans engineered innovative oil lamps to carefully direct lighting onto performers. These lamps utilized adjustable shutters, parabolic reflectors, and lenses to focus their output.
Adjustable Shutters Controlled Beam Spread
The lamps had adjustable shutters on the front and sides. Engineers could control the width and direction of the beam by opening or closing the shutters to block light.
Parabolic Reflectors Intensified and Directed Light
Behind the lamp was a parabolic reflector. This reflected and focused the light from the oil flame into a intense beam. The parabolic shape worked just like a modern spotlight.
Lenses Sharpened and Colored Light
Lenses placed in front of the lamp further refined the beam. Concave lenses sharpened the edges, while colored lenses provided lighting effects. Greens and blues simulated moonlight, reds mimicked the glow of fire.
This optical control allowed spotlights to track performers as they moved across the stage. The Romans were masters of directed lighting centuries before modern stagecraft.
Diffuse Area Lighting Illuminated Upper Seats and Walls
For lighting the upper seats and walls, the Romans used diffuse area lighting. This provided general illumination without glare.
Oil Lamps Mounted on Walls and Pillars
Simple oil lamps were mounted on walls and pillars around the top of the Colosseum. These lacked shutters or reflectors, emitting light in all directions.
Angled Lamps Prevented Glare
The unfocused lamps were angled downwards towards the seats and walls. This prevented glare from impairing the view of seated spectators.
Spaced Lamps Produced Smooth Lighting
The lamps were strategically spaced to provide smooth, continuous light coverage. Too much space and shadows emerged; too little produced uneven hotspots.
Through clever placement, the Romans bathed the top half of the Colosseum in a pleasant glow suitable for general lighting. This complemented the sharply focused spotlights below.
The ancient Romans showed amazing ingenuity in illuminating the Colosseum at night. Their grasps of directed lighting, diffuse lighting, electrical generation, and cable distribution were centuries ahead of their time! As an electrical engineer, I have to tip my hat to those clever Roman predecessors.