This is a transcript of an episode of Public Address Science which was originally broadcast on Radio Live, 13th October 2007, 5 pm - 6 pm.
You can listen to the original audio version of the programme by clicking on the 'Play the audio for this post' link at the top of this page or the 'Audio' button at the bottom of this page.
Background:
[Sound of swords clashing and medieval soldiers shouting]
Voiceover:
This is what it might have sounded like at Hastings in East Sussex on the 14th of October, 1066 -- the day when the army of the invading William, Duke of Normandy, killed King Harold II and conquered England. In fact, what you hear right now is a modern re-enactment of the Battle of Hastings conducted by under-employed history enthusiasts.
As we all know, events turned out badly for the English on that day in 1066. But William's victory resulted in two very useful historical documents, which provide a fascinating snapshot of energy usage at the mid-point (more-or-less) of the Middle Ages. Firstly, the Bayeux Tapestry, essentially a comic-strip embroidery version of the story of the Norman Conquest. And, secondly, the Domesday book -- the inventory of England conducted by William the Conqueror (as he became known) in order to gauge the value of his conquests for tax purposes.
Background:
[Sound of wind over high-tension power lines]
Voiceover:
In last week's episode, we visited the city of Alexandria in 150 AD -- at that time, the intellectual centre of the ancient world. And in Alexandria we discovered that (although the exploitation of energy had allowed a great civilization to flourish) the enormously inefficient way that, for example, wind energy and animal labour were used, meant that the predominant energy source for performing useful work -- such as milling grain, pumping water from metal mines, or propelling ships against the wind -- was still human labour.
Background:
[Sound of swords clashing and medieval soldiers shouting]
Voiceover:
But a millennium or so later the situation had radically changed. Although, as a country, England was practically the middle of nowhere -- part of a rather obscure former Roman province -- even here the
technology for exploiting energy would put the ancient world to shame.
Background:
[Sound of horse and cart]
Voiceover:
The Bayeux tapestry clearly shows that English horses wore horse-collars at the time of the Norman conquest [1]. For the same amount of food, the medieval horse-collar allowed a horse to pull about four times more than if it were wearing a primitive Roman harness [2] -- and this meant that by the middle of the Middle Ages, even in a technological backwater like England, it made a lot more sense to use horse-power rather than human-power.
Background:
[Sound of water wheel]
Voiceover:
And what about those Roman grain mills, driven by slaves running around in enormous human-sized hamster wheels? Well, shortly after the Norman conquest, the Domesday Book records that there were 5,624 mills in England powered by water wheels [3]. That's at least one water-powered mill for every 180 people in the country [3]. It's conceivable that, just by themselves, these water mills (in comparison to human-powered mills) could have freed-up the labour of perhaps 15,000 men -- about one-and-a-half per cent of the English population at that time.
Background:
[Sound of waves and seabirds]
Voiceover:
And what about developments in wind energy? Windmills and wind-pumps wouldn't become part of the English landscape for another century (although they had been widely used in the Middle East since before 950 AD) [4], but some of the ships visiting the English shores did harness wind energy in an improved way -- using a very different approach to the sea-going vessels in the harbour of Alexandria in 150 AD.
These were the Viking ships -- which, incidentally, King Harold II knew all about, because he'd had the very bad luck to have fought off a Viking invasion fleet just two days before the
Norman invasion fleet arrived at the coast of England in 1066 [5].
Background:
[Sound of wind over high-tension power lines]
Voiceover:
Of course, according to some modern historians, Vikings have been unfairly treated by the history books. It's now claimed that they voyaged not in order to murder and pillage, but to form poetry appreciation societies, and to help people in other countries 'get in touch with their feelings' [6]. Whatever the truth of the matter, the Vikings owed a large portion of their success to their ships, which along with several other important innovations, used a device called a Beitiáss or 'tacking spar' to generate lift from square sails [7], and (in contrast to the vessels of the ancient world) to travel against the wind [8]. This much more effective exploitation of wind energy allowed the Vikings to kick up bobsy-die all around Europe, to settle Iceland and Greenland, and even to reach North America [9].
Background:
[Sound of waves and seabirds]
Voiceover:
But the Viking efforts at settlement were peanuts compared to that of the Austronesian voyagers. The Austronesians and their descendents (including, among others, the Polynesians) eventually settled an area that stretched seven-and-a-half thousand kilometres from Hawaii in the North to New Zealand in the South; and eighteen-and-a-half thousand kilometres from Madagascar in the West to Easter Island in the East. And, of course, like the Vikings (but much earlier), their civilization had only become possible by the exploitation of wind energy via the lift-type sail. In fact, descendents of the Austronesians (particularly the Polynesians) quite sensibly always attempted to make their discovery voyages in an upwind direction, thus allowing themselves a safe and rapid homeward journey with the wind [10].
Background:
[Sound of swords clashing and medieval soldiers shouting]
Voiceover:
It's strange to think that 700
years after the Norman conquest, the English-born descendents of the Vikings and the Normans would become so good at harnessing wind energy that they would voyage half-way round the world, and eventually come into contact with the descendents of the Austronesians -- a direct (but trivial) consequence of which is that this radio programme from New Zealand is broadcast in the English language.
But in 1066 it would have seemed absolutely inconceivable that the tiny country of England would go on to "rule the waves" of the world, and become the dominant power in the largest empire in human history. Surprisingly, however, a closer examination of this green and pleasant land reveals a number of plausible reasons why England (and later, Great Britain) had all the right ingredients to make such an outcome possible.
Background:
[Sound of wind over high-tension power lines]
Voiceover:
Obviously, an absolutely essential factor is that England had energy resources in the form of timber fuels, animal labour, flowing water, and wind. And they also had the technology to efficiently exploit these energy resources -- technology either inherited from the Romans, or borrowed from the (at that time) more advanced civilizations in Asia: in particular, China. Furthermore, England had numerous useful raw materials to transform with their energy resources, for example, metal ores such as iron and copper.
England also had the right environmental and political drivers. As Europe's only significant island nation they had the incentive to become experts at exploiting wind energy for seafare. They also existed in a state of competition and almost constant warfare with other European nations, which encouraged them to expand the borders of their empire. After all, if England didn't exploit an opportunity to conquer a weak foreign power, then they could be pretty sure that one of their
European enemies would certainly do so -- in order to augment their own economic and military might.
And, of crucial importance, England (and Western Europe in general) had the vast American continents almost on their doorstep -- or, at any rate, much closer than, for example, the Americas were to other major civilizations such as China.
Finally, the English (and, again, Western Europe in general) had luck. Their language was written with an alphabet that could be efficiently reproduced on a printing press, thus allowing for the rapid dissemination of new information and ideas [11]. And their close contact with agricultural animals for transport energy and food had given them an arsenal of unhealthy germs that would prove absolutely deadly to civilizations in the Americas, Australia, and Oceania [12].
Background:
[Sound of waves and seabirds]
Voiceover:
English mariners would reach North America in 1497 [13]. And shortly afterwards, King Henry VIII -- a descendent of William the Conqueror -- would form a professional English navy [14]. By the end of the 1600s, this navy had become the largest and most formidable in the world [15]; a state of affairs that would last (in the form of the Royal Navy) right up until the early years of the twentieth century [16].
Of course, English (and later British) naval ascendancy wasn't only a matter of efficiency in harnessing wind energy. The English also needed the energy resources and know-how to cost-effectively manufacture auxiliary items (such as metal fittings) for their battle fleets and merchant navy: in particular, to manufacture machines that would make devastating use of a Chinese invention that (when burnt) released energy at a tremendous rate -- gunpowder.
Background:
[Sound of wind over high-tension power lines]
Voiceover:
The material wealth and resources that resulted from their colonies on the American
continents provided the springboard for Britain to eventually seize huge tracts of Africa, Asia, Oceania, and the entire Australian continent [13]. At the apex of its glory, Britain ruled over a quarter of the world's population and land area [17], and had become so vast that -- famously -- the sun never set on its empire.
Background:
[Sound of fire burning]
Voiceover:
But, in order to achieve all this, England had to overcome an important obstacle: the energy bottleneck of its wood resources. The expansion of ship-building in the 1500s -- and the fuel needed for the accompanying manufacture of iron, steel, copper, lead, glass, and gunpowder -- resulted in a 'timber famine' throughout England [18]. These new industries consumed energy on a scale that had never been seen before: Sussex and Kent alone were home to around 7,000 smelters [18]. By the second half of the 1500s the timber famine had became so severe that parliament even passed legislation in an attempt to curb the use of timber as fuel [18].
In the same way that the harnessing of fire led to agriculture and eventually to energy from animal labour, the path to English supremacy in harnessing wind energy for transportation also led to the exploitation of an entirely new energy source. This is perhaps best described in the words of Edmund Howes, writing in 1631:
... there is so great scarcity of wood throughout the whole kingdom that not only the City of London, all haven towns and in very many parts within the land, the inhabitants in general are constrained to make their fires of sea-coal or pit coal, even in the chambers of honourable personages -- and through necessity which is the mother of all arts, they have in late years devised the making of iron,
the making of all sorts of glass, and the burning of bricks with sea-coal and pit-coal [rather than wood] [19].
Background:
[Sound of pick and shovel]
Voiceover:
The English timber famine and the consequent uptake of coal was the first step in the exploitation of a new energy source that would utterly transform the entire world. But more on that next week, when we go down -- into the pits.
Further information on this episode:
- Read about the history of England in Wikipedia.
- Read about the Vikings in Wikipedia.