Some examples of palliative radiation therapy are: 1  Radiation given to the brain to shrink tumors formed from cancer cells that have spread to the brain from another part of the body (metastases). 2  Radiation given to shrink a tumor that is pressing on the spine or growing within a bone, which can cause pain.
The Pharos (Lighthouse) of Alexandria. Built: About 270 B.C. Location: On ancient island of Pharos in harbor of Alexandria, Egypt History: Upon its completion, the Alexandria lighthouse -- commonly estimated to have been about 400 feet high -- was one of the tallest structures on Earth.
They knew that the harbor was near, and they had to steer. This structure helped the sailors for 1500 years before an earthquake destroyed it. Pharos is a Greek word for a lighthouse, and that is why the people who study (or are interested in) lighthouses are called pharologists. For the light wood was burned at first. Slowly, people realized that oil lamps work better, and their light could be seen from a far distance.