Transcript

I work for the National Weather Service and as part of your course on weather patterns, I've been asked to talk to you about how we predict the weather. We're so used to switching on our TVs and getting an up-to-date weather forecast at any time of day or night that we probably forget that this level of sophistication has only been achieved in the last few decades and weather forecasting is actually an ancient art. So I want to start by looking back into history.

 The earliest weather forecasts appeared in the 1500s in almanacs, which were lists of information produced every year. (31) Their predictions relied heavily on making links between the weather and where the planets were in the sky on certain days. In addition, predictions were often based on information like if the fourth night after a new moon was clear, good weather was expected to follow.

But once basic weather instruments were invented, things slowly started to change. (32) In the mid-fifteenth century, a man called Nicholas Cusa, a German mathematician, designed a hygrometer which told people how much humidity there was in the air. To do this, Cusa put some sheep's wool on a set of scales and then monitored the change in the wool's weight according to the air conditions. A piece of equipment we all know and use is the thermometer. (33) Changes in temperature couldn't really be measured until the Italian Galileo Galilei invented his thermometer in 1593. It wasn't like a modern-day thermometer because it had water inside it instead of mercury. In fact, it wasn't until 1714 that Gabriel Fahrenheit invented the first mercury thermometer. In 1643 another Italian called Evangelista Torricelli invented the first barometer which measured atmospheric pressure. This was another big step forward in more accurate weather predicting.

As time went on, during the seventeenth, eighteenth and nineteenth centuries, all these meteorological instruments were improved and developed and people in different countries began to record measurements relating to their local weather. However, (34) in those days it was very difficult to send records from one part of the world to another so it wasn't possible for them to share their information until the electric telegraph became more widespread. This meant that weather observations could be sent on a regular basis to and from different countries. By the 1860s, therefore, weather forecasts were becoming more common and accurate because they were based on observations taken at the same time over a wide area. (35) In 1863, France started publishing weather maps each day. This hadn't been done before, and other nations soon followed. So that was the start of national weather forecasting and I'll now tell you how we at the National Weather Centre get the information we need to produce a forecast.

Even today, one of the most important methods we use is observations which tell us what the weather is doing right now. Observation reports are sent automatically from equipment at a number of weather stations in different parts of the country, (36) They are nearly all based at airports although a few are in urban centres. The equipment senses temperature, humidity, pressure and wind speed direction.

Meteorologists also rely really heavily on satellites which send images to our computer screens. What we see on our screens is bright colours. (37) Orange represents dry air and bright blue shows moisture levels in the atmosphere. The satellites are located 22,000 miles above the surface of the Earth and it's amazing that despite that distance (38) it's possible for us to make out an individual cloud and follow it as it moves across the landscape.

In addition to collecting data from the ground, we need to know what's happening in the upper levels of the atmosphere. So a couple of times a day from many sites across the country, we send radiosondes into the air. (39) A radiosonde is a box containing a package of equipment and it hangs from a balloon which is filled. with gas. Data is transmitted back to the weather station. Finally, radar. (40) This was first used over 150 years ago and still. is. New advances are being made all the time and it is one method for detecting and monitoring the progress of hurricanes, Crucial information is shown by different colours representing speed and direction. Radar is also used by aircraft, of course. All this information from different sources is put into computer models which are like massive computer programs. Sometimes they all give us the same story and sometimes we have to use our own experience to decide which is showing the most accurate forecast which we then pass on to you. So I hope next time you watch the weather forecast, you'll think about how we meteorologists spend our time. And maybe I've persuaded some of you to study meteorology in more depth.

Lecturer: Thank you for coming to this series of talks. Before I talk in detail about the experiments and innovations of the British ceramicists, I’d like to give you a summary of the social and manufacturing background in which they lived and worked. So, we’re talking about England, or more specifically, the region known as ‘TheMidlands’, and we need to go back, mainly to the eighteenth century and, briefly, even earlier, to put it in a global context.

Now, at that period (31) the majority of the population, whatever their station in life, as you might say, were dependent for their living, in one way or another, not on the geographical location of where they lived, but on the physical characteristics of the actual land they lived on. This is true, whether we’re talking about the aristocracy, the owners of great estates, who incidentally had no snobbery about the concept of making money from all the reserves of coal, or timber, or stone on their rolling acres, or the farmers making a fat living from the rich soils. And besides these groups, and the less affluent ones, (32) the deposits of iron ore and lead, the limestone and flint and the brown and yellow clays also sustained the numerous industries in the area.

It’s important to recognize that it was already an industrial region, and had been so for centuries. There were many Midland trades, some of them so indigenous, some of them not. For example, (33) there were immigrants from France who came as early as the late sixteenth century and they were producers of glass. A century later, there is plenty of evidence that the variety of trades was enormous: there was brewing in Burton-on-Trent; silk-weaving and ribbon-making near Coventry; framework knitting around Nottingham. And of course, (34) in Cheshire men dug the salt, as we still do nowadays even, which in that era was sent downriver to the estuary of the Mersey.

Now, among these well-established trades, one the oldest of the local crafts was pottery. As you will probably be aware, ceramics has always been a mix of science, design and skill, and a good potter is in a sense and experimental chemist, trying out new mixes and glazes, and needing to be alert to the impact of changes of temperature on different types of clay. For two hundred years, up to the time we are concerned with, (35) potters had been making butterpots and pitchers and patterned plates, using the clay which was plentiful in the area where they lived – in a handful of North Staffordshire villages dotted along the low hills.

Now I want to explain a little about the industrial processes which had preceded the great breakthrough in Germany in 1708. That’s when the formula for porcelain was discovered, a secret that had been held in China for a thousand years. In the Midlands, in England, as elsewhere, there had basically been two kinds of pottery. The first was known, is still known, as ‘earthenware’.

Now this was a bit rough and ready, but it was deservedly popular for several reasons. To start with, it was relatively cheap, so it could be used by most households. This was because (36) it could be made from local clay without any complicated processing or added materials. (37) From the potter’s point of view there was another reason for its cheapness. This was that it could be fired in simple ovens, or kilns, and at relatively low temperatures, so he didn’t have to spend so much money on fuel to achieve the necessary heat. On the other hand, after one firing in the kiln, the problem with earthenware was that it remained porous so had limited usefulness. So for most purposes (38) it had to go back in the kiln for a second firing before it became waterproof.

And another thing was that it was extremely breakable – I mean, before it had even been sold. I suppose the potter wouldn’t have minded so much if people just had to keep coming back for more every time they broke a jug or whatever! – but it was very inconvenient because it meant there was a lot of (39) wastage in the course of the manufacturing process.

Anyway, for all these reasons, if people could afford it, and that would be all but the very poor, they would buy (40) stoneware, a much tougher product.

Now, for this, the potter used a slightly more expensive raw material, which was made by combining clay and this mixture was fired at a far higher heat, with the result that the ingredients vitrified, that is to say, in effect the whole thing became glassy and because of this it was non-porous, and naturally, this was regarded as a great advance.

Well, that’s the situation in the eighteenth century. Are there any questions at this stage? OK. So, now we can go on to look at the age of innovation.

Lecturer: During today’s lecture in this series about the history of popular music, I’m going to look at the different stages the electric guitar went through before we ended up with the instrument we know so well today.

The driving force behind the invention of the electric guitar was simply the search for a louder sound. In the late 1890s Orville Gibson, founder of the Gibson Mandolin-Guitar Manufacturing Company. (31) designed a guitar with an arched or curved top, as is found on a violin. This made it both stronger and louder than earlier designs but it was still hard to hear amongst other louder instruments.

During the 1920s with the beginnings of big-band music, commercial radio and the rise of the recording industry, the need to increase the volume of the guitar became even more important. Around 1925 John Dopyera came up with a solution. He designed a guitar, known as ‘The National Guitar’, with a metal body which had metal resonating cones built into the top. (32) It produced a brash tone which became popular with guitarists who played blues but was unsuitable for many other types of music.

Another way of increasing the volume was thought of in the 1930s. The C. F. Martin Company became known for its ‘Dreadnought’, (33) a large flat-top acoustic guitar that used steel strings instead of the traditional gut ones. Its was widely imitated by other makers.

These mechanical fixes helped, but only up to a point. So guitarists began to look at the possibilities offered by the new field of electronic amplification. What guitar players needed was a way to separate the guitar’s sound and boost it in isolation from the rest of a band or the surroundings.

Guitar makers and players began experimenting with electrical pickups which are the main means of amplification used today. The first successful one was invented in 1931 by George Beauchamp. (34) He introduced to the market a guitar known as ‘The Frying Pan’ because the playing area consisted of a small round disk. The guitar was hollow and was made aluminum and steel. (35) He amplified the sound by using a pair of horseshoe-shaped magnets. It was the first commercially successful electric guitar.

So by the mid-1930s, an entirely new kind of sound was born. Yet along with its benefits, the new technology brought problems. The traditional hollow body of a guitar caused distortion and feedback when combined with electromagnetic pickups. Musicians and manufacturers realized that a new kind of guitar should be designed from scratch with amplification in mind.

In 1935, Adolph Rickenbaker produced a guitar which took his name – ‘The Rickenbaker Electro Spanish’. (36) It was the first guitar produced in plastic, which, because of its weight, vibrated less readily than wood. It eliminated the problems of earlier versions which were plagued by acoustic feedback. ‘The Electro Spanish’ had its own problems, however, because it was very heavy, smaller than other guitars of the period, and was quite awkward to play. Developments continued and in 1941 Les Paul made a guitar which he called ‘The Log’, and true to its name, (37) it was totally solid. All previous guitars had been hollow or partly hollow. It looked slightly strange but the next step had been made towards the modern electric guitar.

The first guitar successfully produced in large numbers was made in 1950 by Leo Fender. His Spanish-style electric guitar, known as a ‘Fender Broadcaster’, had a bolt-on neck, and was intitially criticized by competitions as being very simple and lacking in craftmanship. Yet it was immediately successful and (38) was particularly suited to mass production, spurring other guitar companies to follow Fender’s lead.

In 1951 Leo Fender revolutionized the music world yet again when he produced an electric bass guitar. This was the first commercially successful bass model to be played like a guitar. It was easier for players to hit an exact note: (39) that’s why it was called ‘The Precision’. Although there had already been electric standup basses, this was much more portable. It is now standard in the line-up of any rock ban and some historians suggest that entire genres of music, such as reggae and funk, could not exist without it.

In 1952 the Gibson company became Fender’s first major competitor when Ted McCarty created ‘The Gibson Les Paul’ guitar. It was distinctive because (40) it was coloured gold. The reason for this was to disguise the face that it was made from two different instrument by introducing ‘The Fender Stratocaster’. It is easily identified by its double cutaway design and three pickups. This model may be the most influential electric guitar ever produced. The modern guitar as we know it was here to stay.

Student: First, I would like to tell you how the Argus computerized photography system has helped marine researchers. Then I shall talk a bit about sand collecting.

Well, Argus is the system Doctor Rob Holman developed when he was working at a research pier on the coast of North Carolina about 20 years ago.

This pier stretches out over the water, and it’s the longest research pier in the world, with an observation tower on the end of it. The researchers there make precise measurements of how the sand moves about under the waves. (31) This research is critical to the study of beach erosion in places where the coastline is being worn away.

The Argus system helps to solve the difficulties encountered by these researchers. (32)  The system correlates the data from under the water with what Dr Holman gets from his fixed camera, which is mounted above the water on the pier  and uses time-lapse photography.

Some of Doctor Holman’s results have changed the way people understand how sand moves. To quote S. Jeffress Williams, a coastal geologist with the United States Geological Survey, the system is ‘a critical piece of new technology’ and ‘The (33) Argus system allows us to quantity and document visually the changes to the coast on a variety of different time frames. A lot ot these take place when there is a storm or at other times when it is difficult to have people out on the beach making observations and taking measurements.’

Up to now Argus installations have been installed in places in Oregon, California, Hawaii, England, the Netherlands, Australia, New Zealand, Spain, Italy and Brazil, as well as in North Carolina.

Now I’d like to introduce Dr Holman’s sand collection. He started collecting sand in the 1980s, and he still collects it now, even though he has around a thousand samples. They come from his travels and from geologists and amateurs all over the world – and (34) the collection includes sand from each continent, including Antarctica.

People send him sand in envelopes, plastic bags, paper towels and all sorts! Each is stored in a glass jar, which Dr Holman labels by latitude and longitude of its origin, as well as he can work them out – sometimes the information is a bit sketchy!

Anyway, (35) it’s mainly geology students at the university who study his collection, and they can learn a lot from it.

For instance, one set of tubes displays sand from the East Coast of the US. So you can see that the sand gets lighter and finer from north to south. By the time a grain of sand eventually washes up on a beach in Florida (36) at the southern and of that journey, it has been battered by waves for a long time so the grains are fine and rounded because most of the time sand is not stationary on the beach.

OK, so if you’d like to collect sand and maybe even send some to Dr Holman, How should you go about it? Well, the list of equipment is very short and easy to find, but you should keep a supply when you’re travelling, as you never know when you’ll come across an interesting sand sample.

(37) One really handy thing for digging sand, especially if it’s hard or frozen, is a spoon, it’s perfect for that. If you’re travelling by air it’ll have to be plastic, but metal is preferable, as plastic tends to break. You need something to put the samples in that is damp-proof and easy to carry. You can just use plastic bags, (38) but you need to record the location and date on the bag, so you must also have a permanent marker with you,  because you can never assume you will remember where you gathered a sample from later on and you don’t want it to rub off before you get home.

And that’s about all you need in the field to collect sand. When you get home, your samples should be logged in a notebook or computer. You need to note the location and be really specific as to exactly whereabouts on the beach you gathered your sample – low tide mark, under cliff area, etc.

Then, you store your sample. You want to keep everything in good condition and avoid contamination. So first you make absolutely sure that each sample is perfectly dry. You don’t need any complicated apparatus for this, (39) you can just air it out on layers of newspaper, which is suitably absorbent. Most people find that’s the best way.

Then, lastly, but this is really important, before there can be any chance of confusing this latest sample with another, you put it in a clean small bag or a jar, and (40) you must stick an identification label on straight away. Some people put one inside as well in case the outer label falls off, but that’s up to you.

Well, that’s about all you need to know to get started as a sand collector.

Any questions?

So now there was a real possibility of having films of more than two or three minutes, and this led to the making of The Great Train Robbery - the very first movie made. It only lasted 11 minutes but was an absolute sensation, and there were cases of people watching the movie and actually fainting when the character fired a gun at the camera! Almost overnight movies became a craze, and by 1905 people in America were lining up to see movies in `store theatres', as they were called then.

I guess the next big step in terms of development of technology was to have people actually talking on the film, and the first step towards this was in 1926 when sound effects were first used on a film. It wasn't until the following year however that the first 'talkie', as they were called then, was made. This film featured actors speaking only during parts of the film and was called The Jazz Singer, and it wasn't until 1928 that the first all-talking film was produced, and this was called The Lights of New York. Unfortunately, the sound on this early film was not very good and I believe they put subtitles on the film - that is, they printed the dialogue along the bottom of the film to compensate for this poor sound quality. Now, with the addition of sound, moving pictures became far more difficult to make ...