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Hannah Fry in BBC Britain's Greatest Invention

Britain's Greatest Invention

BBC Two takes us inside the Science Museum vaults and asks the nation to vote for Britain's Greatest Invention.

About the programme

BBC Two takes us inside the world's biggest invention time capsule - the Science Museum vaults - and asks the nation to vote for Britain's Greatest Invention.

Find out more on the BBC programme page

Discover the range of qualifications and modules from the OU related to this programme:

Hannah Fry, presenter of Britain's Greatest Invention 

Copyright: BBC

Three Unsung Inventions: Tarmac, Time and Propellers

Dr James Warren gives us the lowdown on three unsung inventions and the stories behind the ingenious inventors.


Tarmac – that lovely, sometimes gooey stuff sometimes called back top. Love it or loath it, without it we wouldn’t be able to drive our cars and buses, and landing planes would be nearly impossible.

Construction of a macadam road, "Boonsborough Turnpike Road" between Hagerstown and Boonsboro, Maryland, 1823.

The invention of Tarmac is accredited to Edgar Hooley, an English surveyor who lived from 1860 to 1942.

Although many people think McAdam was the inventor of tarmac – and you wouldn’t be far wrong – it is not quite true. Tarmac is short for tarmacadam – and yes it was named after the Scotsman John MacAdam – but it was Edgar Hooley who named it after him, in honour of his previous incarnation. MacAdam invented the method of crushed stone road surfaces but apparently he failed to make the stones stick down and stick together. MacAdam’s surfaces were fine for horse cart and stagecoaches, but when cars started to become commonplace the surface became inadequate breaking apart due to the forces involved. The rough stone burst lots of tyres and the looseness of the mixture meant that potholes and ruts were well known obstacles especially after heavy rains or flash flooding.

The image here, shows what is must have been like to be a roadman in the United States, long before Hooley made his fantastic discovery. Here, the gang are working on the Boonsborough Turnpike Road which ran between Hagerstown and Boonsboro, Maryland, in 1823, using macadam. Note the well-heeled foremen standing around looking dandy to the far left side whilst the other get on with rock grading and sorting - some things never change!

Hooley worked in Nottingham – where the first paved roads with tarmac were produced but how he discovered the magic formula behind tarmac’s stickiness is quite amazing. He was apparently walking in Denby when he noticed a particularly smooth stretch of road near an ironworks. Hooley studied it intensely – it was smooth with no ruts – and no dust. His curiosity led him to ask around when he found out a barrel of tar fell off a horse cart, burst open and created a sticky mess. The workers at the furnace then dumped cast off slag on the road to help ‘soak up’ the sticky tar…so Hooley had found the right ingredients in 1901. He worked tirelessly mixing up different recipes until he found the correct mixture and went forward with his patent in 1902 and a test area on Radcliffe Road, Nottingham stood the test of time. It was smooth, tough and dust free. The word Tarmac was trademarked in 1903, but Hooley as a business magnate was never a grand economic success as he sold on the business ; it seemed to have grow slowly at first and then from strength to strength. Tarmac is still in business today and together, with concrete, it makes a massive positive impact on our daily lives and contributes to our overall infrastructure.  

Without Hooley’s wonderous countryside discovery, it may have been sometime until tarmacadam had come to the rescue of disgruntled drivers everywhere.

Daylight saving time

Daylight saving time – not actually an artefact but rather a conceptual thing – have you ever wondered why it was created and what all the fuss is about with moving the clocks back and forth twice each year?

William Willett, inventor of daylight saving time

The invention of Daylight Saving Time (DST) in linked to William Willett who lived 1856–1915 – he was a builder and advocate of daylight saving, writing articles and treaties about ‘saving light’.

William Willett was a bit of pioneer with respect to time, and in 1907 he published a short treaty entitled THE WASTE OF DAYLIGHT. In it he stated clearly, and looked ahead into the future with great insight – his opening gambit appealed to many with:

Willett had studied how time could be changed in Australia and South Africa and had decided that natural light could be ‘saved’ or utilised more efficiently by moving the time on clocks. What he was doing, in effect, was trying to get everyone to use the same clock time (a standard set of time) by trying to convince business, railways, workers and the government that by changing clocks that more people would be more exposed to light during the working day and the leisure period after work. He calculated that if time could be moved from 7th April until 22nd September, the UK could be saving £ 2.5 million, even after the deduction of losses for those who sold artificial light. He even explained how a six month trial could show the usefulness of his concept.

However, he failed to get it through the House of Commons in 1908. It was discussed again before World War I, but it never gained traction. Willet’s original proposal was to shift clock time by about 20 minutes each Sunday morning over a series of 4-5 Sundays, which perhaps to current practice seems absolutely batty! He reckoned that the 80 minute shift would yield an extra 1 hour and 10 minutes more daylight each day to all 43 million Britons back in 1907. Eventually daylight saving was enacted as a wartime production boosting mechanism in 1916, under the Defence of the Realm Act. Then it went on to be subsequently adopted in many other countries around the world. By then, though, it was a single move (by 1 hour away from GMT - Greenwich Mean Time also called UTC – Coordinated Universal Time – or simply Standard Time) and in was too late for Willet to see his triumph for he had died from influenza after travelling to Spain to inspect his bauxite company overseas, which supplied their building firm in the UK. Willet’s Family was a well-known building family in Chislehurst area of south London, and a small memorial stand in Petts Woods to Willett for his working on DST.

Home Office Poster - Restoring normal time

Those who were alive during the period after WW2 will have experienced DDST – double daylight savings time – where by the clocks change by two hours during the ‘usual’ summer period (GMT -2) and then stay on DST during the autumn and winter period (GMT -1). DDST ran from early 1941 to late 1945 and many enjoyed the bonus of more light in the evenings after their work. Today we call it BST (or British Summer Time) and if you grew up in other parts of the world, like me, you might remember learning it from the saying “Spring Forward, Fall Back”, so that you didn’t change the clock time in the incorrect direction!

Although many us of might grumble about having to change clocks and adjust to different time, not many would want to give up some of our long mid-summer evenings as Willet’s had accurately predicted. The debate about  double-summer time hasn’t gone away either, with various studies being published showing substantial energy savings if we all moved back to DDST. I wonder if Willet’s really knew what can of worms he had opened?

Marine Screw Propeller Blade

Even if you are nuts about boats and boating, you may not have heard of the Vansittart-Lowe patented propeller. What is even more distinctive about this contraption is that it was invented by someone with seemingly little or no background in marine engineering or ship propulsion.

Henrietta Vansittart, Engineer

The Screw Propeller Blade invention is accredited to Henrietta Vansittart [née Lowe, 1833–1883) a self-trained engineer.

Not much is known about Henrietta’s background, although her father was well known and there is quite a bit written about Jack Lowe – who was also engineer and inventor working on ship propulsion. Jack was rather poor previously, being a smoke jack maker; a roasting jack is the term used for any device that holds meat in front of the fire. From the simplest piece of wire, to more complex clockwork mechanisms that rotated the meat periodically, jack manufacture and sales was a big deal in the 1800’s. Henrietta’s story is much more mysterious and has so many unanswered questions that perhaps it is the most beguiling of all three stories shown here.

We know she was raised in Surrey and London and that the family moved several times, and that she had six brothers and sisters at the time of the 1841 census, all aged from five months up to 15 years old – Henrietta would have been seven. Nothing is known about her schooling or education and there are no significant descriptions of her childhood, so little can be surmised if her later life derived from this. It seems apparent, though, that her father’s work must have had an influence on her. Alan Rothschild goes so far as to call her the new woman inventor and that her work on on improving her father’s design is probably considered one of the most important nautical inventions in the 19th century.

Lowe had already patented the submerged stern mounted propeller in 1838 in an effort to better the partially submerged side mounted paddlewheels in use on many ships. The Lowe propeller seems to have been fitted to many British warships but Lowe never really made any financial gain apparently due to infringement battles. It would seem that there were many different firms competing for the prize of higher nautical speeds and also for the best screw propeller, which then might be endorsed and used throughout the admiralty. So, the family was quite poor and this may have led Henrietta to marry Frederick Vansittart, a Lieutenant based at the British Embassy in Paris (1855). It seems odd that their place of marriage is not known and also that there is no further information on how the two were introduced to each other. 

Shortly after this, her husband returned in England and Henrietta began to work with her father; it is known that she was with Jack Lowe in 1857 aboard the HMS Bullfinch when one of his latest screw propellers was being tested, so we can assume her intellect, confidence and own ability was obvious to those around her. By 1859 she was having an affair with Edward Lytton, a novelist and politician – also known as first Baron Lytton. The affair seems to have been well-known by the families, as well as those in the House of Commons. Henrietta moved out of her husband’s London house and went to live back her grandfather’s place in Surrey (Ewell). 

Tragically, in 1866 her father was run over by a wagon at speed along Blackfriars Road in London, aged 69, and the driver was charged with manslaughter. He was buried in Ewell where Henrietta had taken up residence. So perhaps this shock pushed Henrietta into a new found resolution to win the recognition that her father never had. Her experiments began and in 1868, her propeller was awarded a British patent (# 2877). She went onto gain a patent in the United States (# 89,712) in 1869 for the method of construction of screw propellers. The main thrust of the argument was that her design stopped the water from churning which is the term used to describe useless spinning at the centre. 

In the same year as the American patent, the Navy tested her propeller on the HMS Druid and it was reported in The Times where she is mentioned by name. Her affair with Lytton ended in 1871 in the same year that the Lowe-Vansittart propeller was awarded a prestigious prize at the Kensington exhibition with similar awards following worldwide. The propeller seems to have been fitted to many warships and liners including the Scandinavian and Lusitania. 

In 1873, Lytton died and left Henrietta a large sum of money along with, bizarrely, a smaller sum for her husband, and she went on to write a scientific paper for a presentation at a well-established institution in 1876. Records maintain that Henrietta Vansittart was the first female to author and then present such a paper, with all the diagrams and drawings completed meticulously by herself. Her obituary (from March 1883) says she was remarkable, with a great knowledge of engineering matters and very talented.

It is the final unknown piece of this inventor’s story, when after a visit to the Tynemouth exhibition in late 1882 she was found wandering the streets in a confused state of mind. Henrietta was committed to a lunatic asylum and died there in early 1883 from ‘acute mania’ and anthrax. It is a very sad end to her story and leaves many unanswered questions. Was there something more sinister that took place at the exhibition – her madness does not seem to be described anywhere? It is also not clear why Henrietta did not renew her patent at this time. Could it have been the high cost associated with it (£600 in the UK back then) and the worry that it would have reduced her estate left behind in Lytton’s will? It is not clear what Frederick did after her death – but he lived on until 1902. 

However, without her determination and great skill the ship propeller of the past would not have made such great improvements – ships went faster using less fuel. The shaft had less vibration and the mechanism provided better steering when operating in reverse. A remarkable inventor shaped by incredible events throughout her life leaves me with admiration for what she achieved.

Meet the academic

Dr James Warren, Senior Lecturer in the School of Engineering and Innovation
Dr James WarrenSenior Lecturer - School of Engineering and Innovation, VIEW FULL PROFILE
Dr James Warren, Senior Lecturer in the School of Engineering and Innovation
Dr James WarrenSenior Lecturer - School of Engineering and Innovation,

James Warren is a senior lecturer in the School of Engineering and Innovation and an author on many modules in The Open University which contain transport studies, transport case studies or environmental units linked to mobility. All of his research is publicly available and usually deals with quantifying emissions for particular scenarios or modes of transport. His studies include emissions modelling, ground vehicle propulsion systems, futures thinking (scenario planning, especially for transport) – and frequently include regression models, estimation based on very limited data and growth models (e.g. economic growth). James hold 6 industrially patents in the broad area of automobile catalyst on various devices which reduce pollution – many of these systems are being used successfully on heavy duty trucks around the globe to this day. He is no stranger to invention and has the persistence to strive for a better product.

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