With each new edition the encyclopaedia attempts to capture the current state of knowledge. As a result, looking back at older editions brings to light changes and developments in our understanding and interpretation of the world. The following articles offer a search through the archives, focusing on topics that appear repeatedly through the history of Britannica's publication.

The Allure of the Red Planet | Trace the coverage of Mars, from early anthropomorphic characterizations to recent descriptions of its harsh environment.

Ą bas la Bastille! | "Down with the Bastille!" Read the accounts of the fall of the fortress.

Buried Alive | When Mt. Vesuvius erupted in AD 79, Herculaneum and Pompeii were buried underneath mud and volcanic ash--only to be rediscovered centuries later.

Carbon Copy | Diamonds: Are they forever? Explore the many facets of Encyclopędia Britannica's coverage of diamonds.

The Laughing Animal | According to one encyclopaedia entry, "Laughter enables man to beguile the present, just as forgetfulness shields him from the past, and hope helps him to face the future."

"A Most Digestible Form of Fat" | What do you put on your bread: butter or olive oil? In 1771 butter was familiar to the British, with olive oil only an exotic allusion in the works of foreign writers.

Painting with Broad Strokes | What makes a good painting is notoriously difficult to define--but that hasn't kept people from trying.

The Pope Who Never Was | Is truth stranger than fiction? Medieval historians wrote of a young woman who rose through the hierarchy to become pope.

Shocking Developments | From static cling to thunderbolts, electricity manifests itself in strange ways. No less strange are the ways that scientists have observed and explained it.

Tobacco, "The Holy Herb" | Tobacco was long hailed as a medicinal wonder, a panacea for everything from toothache to the mange. At other times it has been reduced to something "hellish, devilish, and damned."

Troy Story | Homer's epic poems ensured that Troy was among the most famous cities of antiquity. But for millennia scholars had little idea exactly where it was.

Under Wraps | For 30 centuries the ancient Egyptians embalmed their dead, perfecting the elaborate and distinctive art of mummification. Explore the strange history of the mummy.

Unveiling the Mysteries of the Nile | In 1862 John Speke was the first to be able to write: "I saw that old Father Nile without any doubt rises in Victoria Nyanza." After millennia of inquiry, the riddle of the Nile was solved.

When California Was an Island | Encyclopędia Britannica has been writing about California since our first edition in 1768--but at the time we weren't quite sure if it was an island or not.