When a building falls

This lesson asks you to describe factors that can cause a structure to fail. The museum offers two accounts of buildings that fell, in a wind and an earthquake in 425 AH and in heavy rains in 332 AH. They name the events and what fell, not the engineering reasons, so your class must bring the science of forces and materials. ¹

For each building that fell, name the event, the part that failed and what you think was pushing or pulling on it. Mark which of your answers the record states and which are your guesses.

The record on the events of 425 AH says a black wind blew over Nisibin, uprooting many of its orchards and knocking down a palace built of baked brick, stone and lime ². Ramla was shaken, and about half of it was destroyed; part of the wall of Jerusalem fell, and the minaret of the mosque of Ascalon collapsed ². The record on the rains of Baghdad says that in Jumada I 332 the rains multiplied until houses collapsed ³. Both records name the event and what fell, and neither says why it fell.

The record says a black wind knocked down a palace built of baked brick, stone and lime ², and it does not say why the palace fell. Which would you check first, the strength of the wind, the materials or the way the palace was built, and why?

• Earthquake at Ramla, 425: the wind at Nisibin, the shaking of Ramla, and what fell at Jerusalem and Ascalon.
• Rains in Baghdad, 332: the rains, the collapsed houses and what closed in the city.
• Ramla: how the city began and what its founder built there.
• Baghdad: al-Maqdisi relates that before building, al-Mansur asked about the site's winter and summer, rains and air.

Read the earthquake at Ramla and the rains of Baghdad. Make a table with the event, the structure and the part that failed.