Thursday, 2 May 2019

Building a Castle: The Bailey


The bailey or ward in a fortification is a courtyard enclosed by a curtain wall. In particular, an early type of European castle was known as a motte-and-bailey. Castles can have more than one bailey. Their layout depends both on the local topography and the level of fortification technology employed, ranging from simple enclosures to elaborate concentric defences.

Chepstow Castle (carneycastle.com)
Baileys can be arranged in sequence along a hill (as in a spur castle), giving an upper bailey and lower bailey. They can also be nested one inside the other, as in a concentric castle, giving an outer bailey and inner bailey. Chepstow Castle, built on a limestone ridge above the River Wye, has three baileys which were added over time along the ridge, rather than inside one another.

Saturday, 27 April 2019

Research: Mosquitoes


(getty images)
There is no doubt that mosquitoes are a serious threat to mankind. Their bite carries not only malaria but a host of other diseases, such as malaria, yellow fever, Chikungunya, West Nile virus, dengue fever, filariasis, Zika virus and other arboviruses. Mosquitoes kill more people than any other animal: over 700,000 each year, many of them children.

The book A Brief History of the Future suggests that in the next 50 years millions of infertile male mosquitoes would be released to reduce the population, and therefore drastically reduce the incidence of mosquito-borne diseases.

In addition, by replacing the disease-causing organisms injected by their bites with antivirals, mosquitoes can be used to actually immunise the people they bite against an array of diseases. Thus turning them from killers into life-savers.

It's a great idea, but can it become a reality?

Friday, 26 April 2019

Building a Castle: Concentric Castles


When a child draws a picture of a castle, it tends to be a single building. But castles comprise several buildings, and usually two rings of walls. The value of concentric defences was known long before castles existed, in tribal hill forts. The word ‘concentric’ is a little misleading, as the walls were not circular, merely surrounding the site of the castle.
Belvoir Castle, Jerusalem
The first dateable concentric castle was Belvoir Castle in the crusader kingdom of Jerusalem. It was built by Gilbert of Assailly, Grand Master of the Knights Hospitaller, started in 1168. It was built on a high plateau about 20km south of the Sea of Galilea. It overlooks the River Jordan 500m below and was so high and inaccessible that the Muslims called it an eagle’s nest or home of the moon.

Saturday, 20 April 2019

Research: Global Warming


Credit: kwest shutterstock
By 2071 A Brief History of the Future suggests that the global temperature had risen by one degree and Greenland's glaciers were collapsing. Sea level had risen by half a metre and many countries were building flood defences and floating homes.
Coastal erosion at Hemsby UK (BBC)
In the real world, in the UK today, local councils are already planning coastal defences in some places and to leave the coast to erode in others. We have seen dramatic pictures on the news of houses topping over eroded cliffs.

Thursday, 18 April 2019

Building a Castle: Curtain Wall Defences


The curtain wall was the main defence of the castle, but it wasn't just a wall, it contained defences of its own.

Crenellations
Tower of London
The most obvious are the crenellations, the up-and-down parts on top of the wall. They were named after the gaps from which bowmen could shoot, called crenels. The raised parts, providing cover for the bowmen, were called merlons. The wall walks behind the crenellations provided a high vantage point for lookouts and from which to fire on attackers.

Saturday, 13 April 2019

Research: First Mars Colony


A Brief History of the Future by Charles Joynton suggests that the first mission to Mars was sent in 2071. One of the biggest challenges in trying to establish a colony there is the extreme weather conditions. The film The Martian starring Matt Damon illustrated well the extremes of temperature and the dust storms.

An article on the USA Today website by NASA expert Ashley May list four main obstacles to humans living on Mars:
  • We have to land
  • We would need to blast off from Mars
  • We would need to wear spacesuits -- all the time
  • We'd have to get used to dust storms

Thursday, 11 April 2019

Building a Castle: The Curtain Wall


Harlech Castle
The fortifications surrounding the castle were called the enceinte, and the curtain wall was a key part of this. The shape of the walls depended on the site, with many castles built on hilltops, cliffs or rocky promontories. Harlech Castle was built on a near-vertical cliff, making it impregnable from every angle.
Swansea Castle from Castle Bailey Street
The area inside the wall was called the bailey. There is a street in Swansea that runs today in front of the castle ruins, called Castle Bailey Street. The ruins are the remains of the 'New Castle' built in a corner of the old castle which was damaged by Welsh attacks, and towers had been sold to raise money. Castle Bailey Street used to run across the bailey of the much larger original castle.