The first of five clues. Each one below gives a little more away.
My whole purpose is to be avoided.
One of the seven wonders of the ancient world was one of me, at Alexandria.
I speak in a pattern of flashes so you know which one of me you are looking at.
Almost all of us are automatic now. Our keepers are gone.
I stand on the rocks and warn the ships.
Lighthouse
The last civilian lighthouse keeper in the United States retired in 1998. The lights carried on without him.
The invention that mattered was not the tower but the lens. Augustin-Jean Fresnel's design of 1822 replaced a solid glass lump with concentric rings, cutting the weight enormously while gathering nearly all the light into a single beam, and pushed the useful range from a few miles to more than twenty. Each lighthouse then had to be told apart, so every one was given a rhythm — a pattern of flashes and darkness listed in charts, so a navigator could identify the coast by counting seconds. The Pharos of Alexandria kept working for roughly sixteen centuries before earthquakes finished it.
Reading five clues at once is not the game. In the real thing they arrive one at a time and every wrong guess costs an hour. Play mystery #10 · today's mystery · the vault
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