The Tunnel of Samos

Video Segments

The quest for water
Bringing water to Samos
Excavating tunnels from both ends
Hero's explanation
Another explanation
Completing the tunnel
Later history of the tunnel


The water supply of the principal city on the island of Samos in ancient Greece was inadequate for its growing population, but there was an ample supply in the mountains. To bring water from the mountains to the city, a one-kilometer tunnel was dug in the 6th century B.C. through a large hill of solid limestone. The tunnelers worked from both ends and met in the middle, more or less as planned. This module shows how similar triangles probably were used to determine the correct direction for tunneling. The workers who carved the tunnel with primitive tools met at the center with an error les than .15% of the length, a remarkable achievement for that era. The module explains why some error could be expected. It also shows that the problem of delivering fresh water to large populations has been an ongoing human endeavor since ancient times.

After centuries of neglect the tunnel became lost until it was rediscovered in 1882 in a relatively good state of preservation. It contained artifacts dating back to the Roman and Byzantine eras. Shortly thereafter the German archaeologist Ernst Fabricius surveyed the tunnel and published a full description.


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