††Lighthouses are built to warn ships about hazards they might encounter, such as rocks and sandbanks. The first lighthouse on record was built in 283 BC in Alexandria and collapsed due to earthquake in the 4th century. In early lighthouses, the light came from a fire burning in a metal brazier or from candles. In 1759 John Smeaton built a lighthouse using mortar that could set underwater. This made lighthouses more stable and easier to build. Oil lamps came into use around the year 1784, and these have been replaced with electric lamps in modern lighthouses. Most modern lighthouses now work automatically. Each lighthouse has its own pattern of lighting so that ships and aircraft can identify the lighthouse from a distance.
