Day 165 Mile 165: A Mile with a Different Difference Engine

cover1Day 165 Mile 165: A Mile with a Different Difference Engine. 195 years ago today Charles Babbage proposed the Difference Engine to the Royal Astronomical Society in a paper entitled “Note on the application of machinery to the computation of astronomical and mathematical tables”, thus bringing the computer to the world.

It would be quite a trek to go for a run around the Royal Astronomical Society after work today, or indeed the Science Museum in London where several of Babbage’s machines and plans still reside however I can get to a close second.

In 1805 a French engineer named Jacquard invented means for automating the weaving process. He passed a chain of cards, with holes punched in them, in front of a mechanism. The mechanism reached through wherever a hole let it, and picked up a thread. The Jacquard loom principle in textile mills ever since.

cloth loomIn 1820 a wool mill was built in Trefriw, powered by a set of water wheels, processing, weaving and spinning the wool from the surrounding farms. This was then exported up the river Conwy to the coast and out to the world. A large part of the weaving work was done by a loom fitted with a ‘Jacquard machine’. The key operating principal behind this is transmitting a binary sequence of on-off commands, in a very real sense laying the groundwork for our digital age in the heart of the industrial revolution.

‘Wool blanket in red and grey jacquard weave. The centrepiece features the original university building at the University of Wales Aberystwyth (known as the ‘Old College’) and Caernarfon Castle. The words ‘Cymru Fydd’ (Future Wales) and ‘Cymru Fu’ (Wales Past) appear alongside these images. The border is decorated with Welsh dragons, daffodils and leeks. The original was made at Trefriw Woollen Mills, Caernarfonshire, and was presented to the Prince of Wales (later Edward VII) in 1876. Numerous copies (such as the quilt featured here) were subsequently made on a Jacquard loom at the same mill and are still being made to this day.’ Courtesy of Ceredigion Museum

Two years later, in 1822 Babbage conceived a machine that could be told how to carry out a sequence of calculations, programmed by cards working in a binary fashion directly inspired by Jacquard’s weaving machine.

The Difference Engine is an automatic mechanical calculator designed to tabulate polynomial functions. The name derives from the method of divided differences, a way to interpolate or tabulate functions by using a small set of polynomial coefficients. Most mathematical functions commonly used by engineers, scientists and navigators, including logarithmic and trigonometric functions, can be approximated by polynomials, so a difference engine can compute many useful tables of numbers. It was a huge landmark in the early development of computing and set out concepts in programming and hardware architecture that are still in use to this day. The fact that you are reading this is (in part at least) directly attributable to the difference engine and the loom.


An old photo of mine of Babbage’s Difference Engine in the Science Museum (London). 

So today’s run takes a figure of 8 loop around the leafy, mountain village of Trefriw focusing on the Mill at the center. It’s a great little rural run, if somewhat warm and hilly! Highlights include some a really steep hill, both up and down, and the sight of a lady walking two snappy Jack Russel terriers by striding two paces ahead of them with a pair of bright orange tennis balls in a clear plastic bag swung by her side which acted as the perfect lure for her canine charges!

I’m running a mile each day everyday for 2017. If you feel you can sponsor me please do, as all the money raised will go to the Cleft Lip & Palate Association (CLAPA) who provide services all across the UK to support people affected by it.

Distance: 1676.6 meters recorded

(1 mile = 1609.34 m.)

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Thanks as ever for all the support!

Today’s earworm…



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