| A | B |
|---|
| beacon | a signal light |
| fog | thick cloud like masses of condensed water vapor that make visibility poor. |
| foghorn | A horn used by ships t sound warning signals in the fog or darkness. |
| fresnel lens | Invented by the Frenchman, Augustine Fresnel. it bends the light waves radiated from a light on all sides and focuses the light on a single plane, the horizon. |
| keeper | The person who was the care taker of the lighthouse. |
| lighthouse | A tall structure topped by a powerful light ussed as a geacon or signal to aid in marine navigation. |
| navigation | The charting or course of a ship as it travels. |
| prism | A special piece of glass with triangular bases and rectangular sides that bends light. |
| reflection | When light is thrown or bent back as by a mirror. |
| refraction | When light goes through a particular medium such as glass and is bent changing it. |
