Page 161 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

History

How have fridges evolved?

The ingenious methods humans have used to keep food cool

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1700 BCE 1400 BCE 400 BCE 1805 1748 1920s

Ice houses Evaporative Yakhchal Ice box Artifi cial Domestic
1 imri-Lim, the king 2 coolers 3 o store ice in the 4 he ice harvesting 5 refrigeration 6 fridges
T
Z
T
of Mari in Syria, ordered Without access to ice, desert, Persians built industry took off in Artificial refrigeration was Early domestic fridges were

the construction of an ice ancient Egyptians stored mud brick domes. In the 19th century and it first demonstrated by still dangerous and cost
house, which no previous wine in earthenware jars winter, water was led into became common for Scottish chemist William more than a car, but soon
king had ever built. Ice called amphorae. They channels underground people to have an ice box Cullen, but in 1834 US a much safer refrigerant
was collected from nearby would leave the amphora and left to freeze. The in their home. They were inventor Jacob Perkins chemical called Freon was
mountains and stored in outside during the cool ice was moved into the made of wood, lined with built the fi rst refrigerating developed and the fridge
pits in the ground so it nights, and slaves would yakhchal, which had two metal and insulated with machine. However, early soon became a common
would remain cool. Ice sprinkle them with water. parts: the dome and a pit. straw or cork. Ice was fridges were expensive feature of most kitchens.
houses were still used in The cold wind caused the Warm air rose, leaving delivered every few days and used toxic gases as Over the next few decades,
the UK and USA right up water to evaporate, slowly cold air underground to and placed inside to keep refrigerants, making any they became even cheaper
until the 20th century. cooling the wine inside. chill the ice. food from spoiling. faulty leaks deadly. and more eco-friendly.
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William Cullen Jacob Perkins

Why did the dodo die out? The bird’s strong,
Big beak
hooded beak may
have been used
From thriving to non-existent in less than 100 years Redundant wings for defence and to
Due to the availability of settle arguments
ne of the most famous extinction cases in century, the dodo made for a quick and food on the ground, the with rivals over
history, the dodo once inhabited the nutritious meal – and they could be hunted with dodo’s wings weren’t mating rights
needed and they lost
and territory.
Oisland of Mauritius in the Indian Ocean, ease. Without any natural predators, the bird their ability to fl y.
where it thrived due to an abundance of food and was too trusting. Eggs and chicks soon came
a total lack of threat from predation. under fire when the explorers began to bring

The bird was in many ways a victim of its own foreign animals with them. Rats, dogs and cats Large body
evolution, as over time it lost the ability to fl y due raided their nests, while colonisation destroyed The dodo had a thick,
to the abundance of food available to forage for their habitat. This is likely to have been the meaty body, which
on the ground. Their wings withered away while fastest extinction in history and underlines just made for a good meal.
This was one of the
the body grew bigger and heavier. When Dutch how quickly human interaction can ruin the
reasons why it © Alamy
sailors arrived in Mauritius at the end of the 16th lives of a native species. became extinct.
How It Works 161