roller+screen

SUBJECT AREA: Photography, film and optics

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The son of a commercial photographer, Anschütz entered the business in 1868 and developed an interest in the process of instantaneous photography. The process was very difficult with the contemporary wet-plate process, but with the introduction of the much faster dry plates in the late 1870s he was able to make progress. Anschütz designed a focal plane shutter capable of operating at speeds up to 1/1000 of a second in 1883, and patented his design in 1888. it involved a vertically moving fabric roller-blind that worked at a fixed tension but had a slit the width of which could be adjusted to alter the exposure time. This design was adopted by C.P.Goerz, who from 1890 manufactures a number of cameras that incorporated it.

Anschütz's action pictures of flying birds and animals attracted the attention of the Prussian authorities, and in 1886 the Chamber of Deputies authorized financial support for him to continue his work, which had started at the Hanover Military Institute in October 1885. Inspired by the work of Eadweard Muybridge in America, Anschütz had set up rows of cameras whose focal-plane shutters were released in sequence by electromagnets, taking twenty-four pictures in about three-quarters of a second. He made a large number of studies of the actions of people, animals and birds, and at the Krupp artillery range at Meppen, near Essen, he recorded shells in flight. His pictures were reproduced, and favourably commented upon, in scientific and photographic journals.

To bring the pictures to the public, in 1887 he created the Electro-Tachyscope. The sequence negatives were printed as 90 x 120 mm transparencies and fixed around the circumference of a large steel disc. This was rotated in front of a spirally wound Geissler tube, which produced a momentary brilliant flash of light when a high voltage from an induction coil was applied to it, triggered by contacts on the steel disc. The flash duration, about 1/1000 of a second, was so short that it "froze" each picture as it passed the tube. The pictures succeeded each other at intervals of about 1/30 of a second, and the observer saw an apparently continuously lit moving picture. The Electro-Tachyscope was shown publicly in Berlin at the Kulturministerium from 19 to 21 March 1887; subsequently Siemens \& Halske manufactured 100 machines, which were shown throughout Europe and America in the early 1890s. From 1891 his pictures were available for the home in the form of the Tachyscope viewer, which used the principle of the zoetrope: sequence photographs were printed on long strips of thin card, perforated with narrow slots between the pictures. Placed around the circumference of a shallow cylinder and rotated, the pictures could be seen in life-like movement when viewed through the slots.

In November 1894 Anschütz displayed a projector using two picture discs with twelve images each, which through a form of Maltese cross movement were rotated intermittently and alternately while a rotating shutter allowed each picture to blend with the next so that no flicker occurred. The first public shows, given in Berlin, were on a screen 6×8 m (20×26 ft) in size. From 22 February 1895 they were shown regularly to audiences of 300 in a building on the Leipzigstrasse; they were the first projected motion pictures seen in Germany.

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SUBJECT AREA: Photography, film and optics

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As a young man Georges Demenÿ was a pioneer of physical education in France, and this led him to contact the physiologist Professor Marey in 1880. Marey had made a special study of animal movement, and Demenÿ hoped to work with him on research into physiological problems related to gymnastics. He joined Marey the following year, and when in 1882 the Physiological Station was set up near Paris to develop sequence photography for the study of movement. Demenÿ was made Head of the laboratory. He worked with the multiple-image fixed-plate cameras, and was chiefly responsible for the analysis of the records, having considerable mathematical and graphical ability. He also appeared as the subject in a number of the sequences. When in 1888 Marey began the development of a film camera, Demenÿ was involved in its design and operation. He became interested in the possibility of using animated sequence photographs as an aid to teaching of the deaf. He made close-up records of himself speaking short phrases, "Je vous aime" and "Vive la France" for example, which were published in such journals as Paris Photographe and La Nature in 1891 and 1892. To present these in motion, he devised the Phonoscope, which he patented on 3 March 1892. The series of photographs were mounted around the circumference of a disc and viewed through a counter-rotating slotted disc. The moving images could be viewed directly, or projected onto a screen. La Nature reported tests he had made in which deaf lip readers could interpret accurately what was being said. On 20 December 1892 Demenÿ formed a company, Société Générale du Phonoscope, to exploit his invention, hoping that "speaking portraits" might replace family-album pictures. This commercial activity led to a rift between Marey and Demenÿ in July 1893. Deprived of access to the film cameras, Demenÿ developed designs of his own, patenting new camera models in France on 10 October 1893 and 27 July 1894. The design covered by the latter had been included in English and German patents filed in December 1893, and was to be of some significance in the early development of cinematography. It was for an intermittent movement of the film, which used an eccentrically mounted blade or roller that, as it rotated, bore on the film, pulling down the length of one frame. As the blade moved away, the film loop so formed was taken up by the rotation of the take-up reel. This "beater" movement was employed extensively in the early years of cinematography, being effective yet inexpensive. It was first employed in the Chronophotographe apparatus marketed by Gaumont, to whom Demenÿ had licensed the patent rights, from the autumn of 1896. Demenÿ's work provided a link between the scientific purposes of sequence photography— chronophotography—and the introduction of commercial cinematography.

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SUBJECT AREA: Paper and printing

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After education at a private school, Dickinson was apprenticed to a London stationer. In 1806 he started in business as a stationer, in partnership with George Longman; they transferred to 65 Old Bailey, where the firm remained until their premises were destroyed during the Second World War. In order to secure the supply of paper and be less dependent on the papermakers, Dickinson turned to making paper on his own account. In 1809 he acquired Apsley Mill, near Hemel Hempstead on the river Gade in Hertfordshire. There, he produced a new kind of paper for cannon cartridges which, unlike the paper then in use, did not smoulder, thus reducing the risk of undesired explosions. The new paper proved very useful during the Napoleonic War.

Dickinson developed a continuous papermaking machine about the same time as the Fourdrinier brothers, but his worked on a different principle. Instead of a continuous flat wire screen, Dickinson used a wire-covered cylinder which dipped into the dilute pulp as it revolved. A felt-covered roller removed the layer of wet pulp, which was then subjected to drying, as in the Fourdrinier machine. The latter was first in use at Frogmore, just upstream from Apsley Mill on the river Gade. Dickinson patented his machine in 1809 and claimed that it was superior for some kinds of paper. In feet, both types of machine have survived, in much enlarged and modified form: the Fourdrinier for general papermaking, the Dickinson cylinder for the making of board. In 1810 Dickinson acquired the nearby Nash Mill, and over the years he extended the scope of his papermaking business, introducing many technical improvements. Among his inventions was a machine to paste together continuous webs of paper to form cardboard. Another, patented in 1829, was a process for incorporating threads of cotton, flax or silk into the body of the paper to make forgery more difficult. He became increasingly prosperous, overcoming labour disputes with unemployed hand-papermakers. and lawsuits against a canal company which threatened the water supply to his mills. Dickinson was the first to use percolation gauges to predict river flow, and his work on water supply brought him election to a Fellowship of the Royal Society in 1845.

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blind or screen, esp. on roller, for window; balustrade