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Pencil Eraser
In 1770, the English chemist Joseph Priestley made the first mention in English that a piece of a rubber substance could erase marks from black-lead pencils. In an addendum to his work Familiar Introduction to the Theory and Practice of Perspective, he described it, and that it was

sold by Mr Nairne, Mathematical Instrument Maker, opposite the Royal Exchange. He sells a cubical piece of about half an inch for three shillings.

Periodic Table
Lothar Meyer (1830-1895) was a German chemist who, independently of Dmitry Mendeleyev, developed a periodic classification of the chemical elements. He recognized that the properties of an element seem to depend on its atomic weight. Meyer plotted the values of the atomic volume, against atomic weight and found clear signs of periodicity - the graph consisting of a series of four sharp peaks. He noticed that elements with similar chemical properties occur at comparable points on the different peaks; e.g., the alkali metals all occur at the tops of the peaks. Meyer did not publish his table until 1870, a year after Mendeleev had published his periodic table. Meyer later stated that he lacked sufficient courage to have gone on to predict the existence of undiscovered elements.

Georg von Peurbach
Peurbach (1423-1461) was an Austrian mathematician and astronomer who attempted to refine the Ptolemaic system, on which current planetary science was based. His enduring contribution was in promoting the use of sine tables written in Arabic numerals rather than Roman numerals. The Arabic system had been introduced 250 years earlier by Fibonacci (1170-1240) but had not yet been universally adopted. Peurbach calculated his sine tables with unprecedented accuracy but died before his project could be completed. His collaborator was his pupil Regiomontanus (1436-1476), who added a knowledge of Greek to Peurbach's understanding of Ptolemy's mathematics. Regiomontanus continued it until his own death. In his Theoricae Novae Planetarum (New Theory of the Planets) Peurbach insisted on the solid reality of the crystal spheres of the planets, tasking Ptolomy's work a stage further. This became the primary astronomy textbook, replacing The Sphere of Ptolemy (100-170). He was then commissioned to translate the Almagest in which he collaborated with his pupil. Together, they produced the Epitome of the Almagest, the clearest rendering of Ptolemy's work yet translated. He also calculated tables of eclipses in Tabulae Ecclipsium, observed Halley's comet in Jun e1456 and the lunar eclipse of the 3rd of September 1457 from a site near Vienna.

Photophone
In 1880, Alexander Graham Bell transmitted the first wireless telephone message on his newly-invented photophone. The photophone worked by projecting his voice through an instrument towards a mirror. The vibrations in the voice caused similar vibrations in the mirror. At the same time sunlight was directed into the mirror and captured and projected the mirror's vibrations. The vibrations could then be deconstructed back into sound at the receiving end of the projection. In this way the photophone functioned in much the same way as the telephone but used light as a means for projecting the information instead of electricity, which is used by the telephone.

Pirate Radio
Unlike most other countries, legal commercial radio only began in Britain in 1973, many years behind a mature and respected commercial television market. During the 1950s and 60s, popular music radio in Britain consisted of just a couple of hours a week on the BBC. The Home Office, responsible for operating the broadcasting laws, protected the BBC by refusing to countenance the issuing of broadcasting licences to commercial competitors. Most fans, in desperation, tuned in to night-time transmission from Radio Luxembourg, taking advantage of an ionospheric 'skip' which occurred after dark. In 1964, and Irish man, Ronan O'Rahilly, who ran a London club called the Scene, and also managed an up and coming star called Georgie Fame decided to start his own radio station. A former Danish passenger ferry named The Frederica, was fitted out at Greenore in Ireland and renamed the MV Caroline after John F Kennedy's daughter. Caroline came on the air on Easter 1964,broadcasting high powered signals from just outside British territorial waters and therefore, just beyond the reach of British law. The idea spawned a large number of offshore Pirate stations devoted a wide range of "alternative" music transmissions. These continued for three and a half years until the Government enacted a law which made them illegal. The BBC now stepped in to provide, at last, a 'pop' music channel.
The early years of "the replacement' Radio One provided listeners with an eclectic mix of MOR, Pop, R&B and many different streams of music in a doomed attempt to replace the many that had been closed in August 1967. There was a short resurgence of offshore radio in the early 1970's and in 1973 the Government finally passed a law which allowed legal commercial radio. The early commercial stations, based in the major populated centres of Britain, struggled to establish themselves against the backdrop of extremely difficult economic conditions - the miners' strike had led to the necessity of the three-day working week - and advertising was notoriously difficult to attract. The BBC was still partly protected as the commercial stations, were prevented by the constraints of the trade unions, from broadcasting more than eight hours of so called 'needletime'. The other sixteen hours were often filled with plays, other non performing-rights material. This lasted until 1989 when the stations began to defy the unions and flex their own muscles. In 1989, also, the newly created Radio Authority began to licence smaller commercial broadcasters with a more local focus. Even so, the licensing system in Britain is far from ideal and the expansion of a truly unfettered commercial radio network is probably still a long way off.

Pitt-Rivers
Henry Lane-Fox Pitt-Rivers (1827-1900) was the English archaeologist who is often called the "father of British archaeology." He strongly advocated the need for total excavation of archaeological sites with a thorough stratigraphic observation and recording, followed by prompt and complete publication. Like Sir Flinders Petrie, Pitt-Rivers adopted a sociological approach to the study of excavated objects and emphasized the instructional value of common artifacts. His London home became so crowded with items such as skulls, stone implements, pottery and other works of art that he decided to open a public museum at Bethnal Green, which he arranged according to his evolutionary system. When his collection became too large for Bethnal Green, it was transferred to the University of Oxford, where it is still housed today.

Norman Robert Pogson
Pogson (1829-1921) was an English astronomer who suggested a classification of the brightness of stars in 1850. He defined decimal increments of magnitude to refine the existing scale which employed only integer magnitudes. He used a scale in which a first magnitude star was one hundred times brighter than a sixth magnitude star. There a 2.512-fold change in brightness will bring about a change of one unit of magnitude. Because first magnitude stars are, by definition, the brightest all other magnitudes are expressed as negative numbers. (This has confused many a student.) On this scale, our Sun is magnitude -26.91 and Sirius is magnitude -1.58.

Polythene
In 1933, polyethylene was discovered by Reginald Gibson and Eric William Fawcett. It was one of the earliest plastics to come into common use and was discovered by accident while ethylene and benzaldehyde were reacted at high pressure. The demands of war and the need for a better insulator for cables stimulated the development of polyethylene and it played a key role in the development of radar. It became ubiquitous after the war and was widely used for plastic bags, food containers and other packaging.

Richard Anthony Proctor
Proctor (1837-1888) was an English astronomer who was the first to suggest, in 1873, that lunar craters were the result of meteor impacts and not volcanic action as had previously been assumed. In 1867 he made a map of the surface of Mars showing continents, seas, bays and straits. In this respect he followed Riccioli's mapping of the moon. He did not distinguish channels (NOT canals) seen by the Italian astronomer Schiaparelli after him.

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