H00: How Lighthouses Work
H01: Fire
H02: Light
H03: Light Sources
H04: Brightness
H05: Measurements
H06: Photometric Definitions and Calculations
H07: Horizon and Height
H08: Light Intensity
H09: Materials Interaction
H10: Reflection
H11: Refraction
H12: Lenses and Prisms
H13: Light Generation
H14: Coal
H14a: Candles
H15: Wood
H16: Vapourised Paraffin
H17: Acetylene
H18: Carbon Arc
H19: Electric Light Bulbs
H20: Electrical Supplies
H21: Intensity Reduction
H22: Light Colour
H22a: Flashing Light
H23: The Optic
H24: Optic Rotation
H25: Lighthouse Characteristics
H26: Magnification
H27: Catoptric, Dioptric and Catadioptric Systems
H28: Occulting Systems
H29: Reflecting (Catoptric) Systems
H30: Leading Lights and Sector Lights