Page 172 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

From the outside, St Francis
Church looks like any other
Gothic-style building

© Getty Images

What is the Chapel of Bones?

he outside of St Francis Church in Evora, to the church for storage. This was normal The bones act as a reminder of
TPortugal looks just like any other practice for the time, but rather than hide the transience of life
Renaissance church. But step inside and you them away in underground tombs, the
will discover a dark secret hidden within its monks decided to put the bones on display.
walls – a chapel made out of bones. The They believed that this monument would were pressed into them. Two desiccated
Capela dos Ossos, or ‘Chapel of Bones’, was help to remind their fellow brothers of their corpses were also hung from the ceiling by
built by a group of Franciscan monks in the own mortality. ropes. No one really knows who these two
16th century. When the city’s cemeteries The walls and central pillars of the chapel skeletons belong to, but some people believe
became overcrowded, the remains of were covered with cement, and then the they are those of an adulterous man and his
thousands of deceased people were brought bones and skulls of around 5,000 skeletons son, cursed by a jealous wife.

Who invented the first keys?

ne of the earliest known examples of a key and lock system was used in
OEgypt 4,000 years ago. The simple mechanism consisted of a wooden
bolt secured to the door, with several wooden pins gripping it into position.
The wooden key resembled a toothbrush in shape and featured pegs at the
end that, when inserted into the lock, pushed the pins upwards to release the
bolt. However, this offered little security, as any key could open any lock. To
solve this problem, the Romans developed the warded lock, often made of iron
or bronze. Notches and grooves called wards were cut into the keyhole, so that

only keys cut with corresponding notches and grooves could fit into it. Warded
locks still weren’t particularly secure though, as instruments could be

fashioned to fit the wards and pick the lock, but they still remained in use for
centuries. After a few more attempts at developing a more secure system, it © Corbis; Thinkstock
wasn’t until the 1800s that American Linus Yale and his son Linus Yale Jr
The bronze and iron warded lock system
developed the spring-driven pin-tumbler lock that is still commonly used today. was used throughout the Middle Ages

172 How It Works