Category Archives: Materials

‘A weapon calling for careful handling’…

February 4th marks World Cancer Day. Alongside surgery, chemotherapy and hormone treatment, radiotherapy has been a mainstay of cancer treatment for well over 100 years. Just weeks after Wilhelm Roentgen’s discovery of x-rays in 1895, student doctors began experimenting with the mysterious rays to treat cancer, and other conditions such as ringworm.

By the 1920s, x-ray generators weren’t capable of making the intense beams of radiation needed to treat certain tumours. Hospitals turned to experimenting with radioactive materials such as radium.

This strange looking contraption is a radium ‘bomb’. It’s a rather ingenious machine developed at London’s Westminster Hospital for cancer treatment in the early 1930s.  

The 'bomb' - the egg-shaped treatment head pictured on the left – was a lead-lined container for radium that restricted the beam of radiation. It was extremely heavy, and to keep it in position its weight was offset by the counterbalance you see at the bottom. (credit: Science Museum Photo Studio).

Why does it look so odd? Well its designers were faced with several difficult dilemmas – how to deliver treatment to the patient whilst keeping staff safe from radiation exposure? With radium costing over £200,000 an ounce, maximizing the effect of the few grams of radium received on loan from the government, was a critical concern.

Like much experimental medical apparatus, this equipment was made in the hospital’s own workshops. In fact it was made up of bits of bike! Staff could be kept at a safe distance when positioning the ‘bomb’, and to expose the patient’s tumour to the radium – a shutter was operated via a bicycle brake cable.

When not in use, hospitals would keep radium buried in lead-lined chambers – protection that became critical with the impending threat of actual bombs during the Second World War.

Women painting alarm clock faces

Women painting alarm clock faces, Ingersoll factory, January 1932 (Science Museum)

Cancer treatment went on to change rapidly. More powerful radiation sources were developed, such as linear accelerators. Atomic reactors also helped to transform the situation – through producing large amounts of alternative radioactive material such as cobalt-60.

Oddy Oddy Oddy

Would you like to take a test to see what you’ll be like in the future?

Well, if so an Oddy test could be what you’re looking for - although unfortunately it’s not suitable for human testing.

An Oddy test is an accelerated aging procedure that we carry out on materials to see how they’ll react over time. It was first introduced by Mr Andrew Oddy in the 1970s and materials are enclosed in a test tube with metal coupons and heated over 4 weeks. The principle is that the heating accelerates the aging of the material.

The setup for oddy testing materials (Kayleigh Beard, 2010)

We use Oddy tests in museums to test how materials which are used for storage and display are going to react over time.

We can tell whether a material is suitable for use by looking at the metal coupons within the test tube. For example, if the material gives off gases while it ages the accelerated aging in the test tube will cause the metal coupons to corrode – obviously we don’t want this to happen to our objects!

You can also look at the condition of the materials after the 4 weeks and if cracking has begun to occur it may indicate that after 10 years your material will no longer be strong and stable.

Metal coupons used in Oddy testing. Compared to control coupons you can identify if corrosion is present. (Kayleigh Beard, 2010)

Currently we are working alongside the British Museum to try and build up an archive of Oddy tested material. The aim is to then make the results of these tests available to other museums.

Sharing knowledge means that museums can ensure they are looking after their collections using the best possible materials. Not so odd afterall…

Joule’s spiders

Before my first visit to the Science Museum’s stores, I’d imagined having to search for my mysterious magnetic instruments in the midst of much dust and cobwebs in the warehouse from the closing scenes of Citizen Kane.

In the rather more ordered and hermetically sealed rooms of Blythe House, the spider threads I found were of a much cosier sort. Encased in their own tiny frame, they rather reminded me of my great-grandparents in their wedding portrait.

Two kinds of Diadema spider thread, as used in Joule's dip circle. (Alison Boyle / Science Museum)

The two cocoons of Diadema spider silk are surviving samples of the types used in the dip circle designed by James Prescott Joule. (Yes, that Joule.)

James Prescott Joule, English physicist, 1882. (Science Museum / Science & Society)

As scientists became more interested in magnetic phenomena in the late eighteenth century, more effort was made to improve the apparatus used in their study. The friction of pivoted needles found in many magnetic instruments was a problem limiting the accuracy and ease of making measurements.

The usual method involved the needle’s cylindrical axle rolling on agate planes as it aligned itself with the surrounding magnetic field.

A needle on an agate plane, in a dip circle by Robinson, c.1830. (Science Museum / Science & Society)

Joule turned to spider threads to create an alternative suspension method. JD Chorlton examined one of Joule’s dip circles after the latter’s death, describing it as follows:

“The needle, constructed of a thin ribbon of annealed steel, weighing 20 grains, is furnished with an axis made of a wire of standard gold. This axis is supported by thread of the Diadema Spider attached to the arms of a balance suspended by a fine stretched wire. The whole is hung by a wire which can be twisted at the head through 180°”.

Strong, resilient and light, spider silk sounds like an ideal material. In practise the silk was too fiddly, and the needle’s weight and friction with the axle meant that the thread would be prone to snap. Still - it’s a lovely story which gives a sense of the patience, precision and ingenuity required of scientific investigation.

Space Debris

X3/Prospero thermal surfaces experiment

X3/Prospero thermal surfaces experiment (Doug Millard, 2005)

This box contains a flight spare set of experimental surfaces for the Prospero satellite that was launched in 1971. They were designed to tell scientists more about how different satellite materials and finishes – matt, shiny etc, would behave in the temperature extremes of space.

It has always reminded me of a much larger experiment flown by NASA (LDEF - which stands for Long Duration Exposure Facility) that was covered with all sorts of equivalent surfaces.

LDEF satellite during its six year stay in orbit

LDEF satellite during its six year stay in orbit (NASA)

The LDEF was brought back to Earth in the Shuttle and scientists discovered that its surfaces were covered with impact craters from micro-meteoroids.

Micro-meteoroid impact crater on the LDEF satellite

Micro-meteoroid impact crater on the LDEF satellite (NASA)

That was back in the 1980s but if the mission were to be repeated now it would almost certainly suffer many more collisions from the bits of space debris that we have put up there. There are thousands upon thousands of pieces of rocket and spacecraft circling Earth and it is becoming a big problem for satellite operators.

Computer representation of just some of the debris pieces orbiting Earth

Computer representation of just some of the debris pieces orbiting Earth (NASA)

At a meeting last week Air Commodore Stuart Evans RAF, Head of Joint Doctrine, Air and Space, DCDC, pointed out that ‘all nine sectors of the UK’s critical national infrastructure (communications, emergency services, government and public services, finance, energy, food, health, transport and water) all rely, to a greater or lesser degree, on space.

What to do about the debris problem, then? There is no simple answer at the moment and all the space players can do is ensure as little new debris is created as possible.

Prospero is still in orbit and next October scientists hope to re-contact it for its 40th anniversary. They won’t be able to examine those experimental surfaces but if they could I wonder what state they would be in now!

Killer snakes, steel knots and a silver laboratory

In my last post I showed you a section of gun barrel flattened cold by a steam hammer. Spectacular demonstrations of engineering muscle have often yielded cool Science Museum exhibits, and I thought you might like to see another one on show in our Making the Modern World gallery:

Knot of steel, 1885 (Science Museum / Science & Society)

This is a knot, tied cold, formed by a pair of inch-diameter rods of steel. It was made in 1885 at the Steel Company of Scotland, Glasgow, and comes from a collection of 3,700 metallurgical specimens put together by Dr John Percy FRS. We bought the collection upon Percy’s death in 1889.

John Percy, English metallurgist, 1859 (Science Museum / Science & Society)

Percy was the inaugural Professor of Metallurgy at the School of Mines, the first government-backed technical higher education establishment in the UK, and taught there from 1851 to 1879. Here’s his laboratory:

John Percy's metallurgical laboratory, 1877 (Science Museum / Science & Society)

Percy had made a name for himself in the 1840s for a new method of extracting silver from ore, which went into widespread use. He went on to develop new ways to make steel, improving Bessemer’s process.

His collection was eclectic, to say the least. While reading through the files in order to write this blogpost, I saw that another of the items in his collection was a box of boa constrictor dung, used as a fuel for smelting. Ingenious…

The School of Mines ended up as part of the Department of Materials at Imperial College, next door to the Science Museum. You can read the history of the school in a super booklet written by Imperial’s wonderful archivist, Anne Barrett.

And if you’re going there to study this autumn, do drop by and see us.

Liquid steel and an underground time machine

My attention was drawn last week to an incredible set of photographs taken recently in Notting Hill Gate underground station, during refurbishment. They show a deserted passageway sealed up in 1959, with advertising posters surviving untouched to this day:

Hidden lift passage, Notting Hill Gate station, 2010 (London Underground / Mike Ashworth)

The full set, by London Underground’s Head of Design and Heritage, Mike Ashworth, are on Flickr. One of them advertises the Science Museum’s then-new Iron and Steel gallery, depicting a Bessemer steel converter in mid-pour:

Science Museum 'Iron and Steel Gallery' poster, Notting Hill Gate station, c.1959 (London Underground / Mike Ashworth)

I’ve spoken before (in posts about Barrow-in-Furness and Bessemer) about our 1865 converter. It’s now in Making the Modern World but back in the sixties it was in Iron and Steel, as shown here:

Science Museum audioguides, 1961 (Science Museum / Science & Society)

(Hand-held audioguides aren’t a recent museum phenomenon. We were trying them out in the sixties!)

In front of the converter you can see a flattened metal ring. It’s a section of round gun barrel, squashed flat by a steam hammer. It was done cold, and there’s no cracking.

Section of Bessemer steel hammered flat, 1860 (Science Museum / Science & Society)

It was a demonstration carried out by Bessemer in 1860 to show the superb ductility (flexibility) of his steel, which made it such a useful material – giving us longer bridges, bigger ships, taller buildings, stronger machinery and rails to take heavier and faster trains. You can see it in Making the Modern World, too.

Iron and Steel was replaced in 1995 by our current Challenge of Materials gallery.

(Thanks to Mike Ashworth and London Underground for sharing their pictures.)

The goodness of wood

I stumbled across an old Monty Python sketch the other day that plays with words pleasing to the ear (‘woody’) or displeasing (‘tinny’). I chortled (nice woody word) but then started thinking about wood and science - we don’t often associate the two and we’re culturally conditioned to associate wood with words like ‘old’:

Roe Triplane at Lea Marshes, 1909

Roe Triplane at Lea Marshes, 1909 (Science Museum/Science & Society)

and ‘amateur’;

Man Sawing Wood, 1997

Man Sawing Wood, 1997 (Science Museum/Science & society)

But appearances can be deceptive as the Mosquito aircraft demonstrated. It may have resembled its alloy contemporaries of World War 2 but its sleek exterior cloaked a strong, lightweight structure of balsa, birch and spruce.

And the very obviously metallic masts and aerials of Rugby Radio Station, long standing landmark twixt the A5 and M1, relied on a hidden, cathedral of wood – the Linden or Lime Wood-supporting structure for the transmitter’s tuning coil assembly.

Rugby Radio Station’s Very Low Frequency Tuning Coil Assembly, 2004

Rugby Radio Station’s Very Low Frequency Tuning Coil Assembly, 2004, (Science Museum).

And lest we think of the space age as an era of quintessentially expensive and exotic materials we should remember that Apollo astronauts needed cork to get to the Moon (it lined the boost protective cover that protected their command module and windows should the launch escape system be used),

Apollo Launch Escape System, 1968

Apollo Launch Escape System, 1968 (NASA)

and that China’s Fanhui Shei Weixing reconnaissance satellite had oak in its heat shield to help it ablate (burn away and dissipate the heat of atmospheric re-entry).

A lot of hot air?

How did you enjoy the hottest day of the year so far on Sunday? It got me thinking about what else we have in the collection relating to temperature.
 
For simplicity, I like this modern reconstruction of an apparatus which Philo of Byzantium devised back in 200 – 100 BC to indicate temperature change. A hollow, lead globe is attached to a tube, which is bent over into a container of water. You can probably guess what happens when the globe is warmed…
Reproduction of Philo's thermoscope

Reproduction of Philo's apparatus for indicating temperature change (Science Museum / Science & Society)

Philo explained:  

I assert that when the globe is placed in the sun and becomes warm, some of the air enclosed in the tube will pass out … into the water, setting it in motion and producing air bubbles, one after the other. If the globe be placed in the shade … then the water will rise through the tube and flow into the globe. 

Some seventeen or so centuries later Philo’s idea was revisited, leading to the invention of the air thermoscope. The Italian physician Santorio Santorio was one of several Europeans working on it simultaneously.

Illustration of Santorio's air thermoscope

The two pieces of string tied round this air thermoscope indicate a rise in temperature. From Sanctorii Sanctorii, ... Ars de statica medicina, etc., 1625 (Wellcome Library, London)

Santorio’s instrument is in two parts. The glass bulb and tube are heated to expel some air, and the end of the tube is inverted into the narrow vessel containing water. As the air inside the bulb cools it contracts, drawing liquid up into the tube.  Once it has been set up, the changing water level indicates rising and falling temperature.

Santorio later put a scale on the thermoscope, creating the first air thermometer.  The air thermometer was supplanted by the more familiar liquid-in-glass thermometer from the 1640s. More on that another time. 

Combined thermometer and alcohol barometer, 1719

Combined thermometer and alcohol barometer, 1719 (Science Museum / Science & Society)

Steel yourself for a visit to Barrow

You may have been following my recent posts on Britain’s submarine history. One thing that’s emerged has been the important role of Barrow-in-Furness in transport history.

The Vickers company, now part of BAE Systems, made most of Britain’s submarine fleet at their Barrow yard, and BAE are manufacturing our latest subs there now.

But Barrow was a transport town long before the submarines. In the mid-nineteenth century, Barrow became a centre for steel-making, as iron ore mined in the nearby Lake District was brought to the town by rail.

Experimental Bessemer converter, 1865 (Science Museum / Science & Society)

This device, a prototype Bessemer converter, was made at the Barrow Haematite Ironworks in 1865, and is on show at the Science Museum. Large-scale converters that followed enabled steel to be made in vast quantities.

This plentiful local steel supply, coupled with Barrow’s sheltered waterside, made the town an ideal place to build ships, and Barrow yards churned out countless vessels before turning towards submarines in 1900.

The railway line that transported the iron ore which enabled this whole industry to thrive was a significant network in its own right.

Barrow railway station, 1930 (NRM / Science & Society)

We’ve got lots of Furness Railway items in the National Railway Museum collections, including ‘Coppernob’, on show in the NRM Station Hall

'Coppernob' locomotive for Furness Railway, 1846 (NRM / Science & Society)

…paintings in the art collection…

Oil painting of a train on the Furness Railway, 1910 (NRM / Pictorial Collection / Science & Society)

…and delightful archive items.

Furness Railway timetable, 1915 (NRM / Science & Society)

Today, parts of the Furness Railway are still used by the national rail network, including the line to Barrow. It’s an area with a long and enduring history.