The Science Society

The School Orchestra

Gretry (1741-1813)

INTERVAL OF TEN MINUTES

PART II

Part of "ELIJAH"

Felix Mendelssohn—Bartholdy (1809-1847)

Elijah - Arthur Taylor Ahab l - Mr. E. P. Piers Obadiah The Youth - M. R. Pallant The School Choral Society and Orchestra

Five meetings have been held this term.

The first meeting, held after supper on 24th January, consisted of a film show. "Beginnings of History" traced man's development from half a million years ago through the Old Stone Age, New Stone Age,

Bronze Age and Iron Age, to the coming of the Romans to these islands. Some specimens of flint weapons from the School Museum were passed round. A film, describing the new survey of the country and brickmaking, was also shown. A On 31st January, Mr. Jeffs, assisted by Markus, gave a most interesting and instructive talk-film show-demonstration on Radar, a subject on which he is an authority. He traced its history from 5938, when it was known as R.D.F. (Radio direction-finding) and explained the principle of Radar by analogy with echoes in sound. The time intervals involved between the transmission and reception of the wireless waves are of the order of a micro-second and are measured by the Cathode Ray Oscillograph. A film on the C.R.O, with a commentary by R. A. Watson-Watt, the father of Radar, was shown.

With the help of diagrams, Mr. Jeffs explained the plan of a simple radar set and how sets are calibrated for range. He described how not only distances but bearings of objects could be obtained and how a picture of the surrounding countryside could be obtained. He concluded with a demonstration of fighter direction, aided by Markus and Cross. As messages came over the loudspeaker, giving information obtained by radar of approaching "enemy" formations, Mr. Jeffs plotted on the blackboard their approach and their interception and dispersal by fighters. So realistic was it that we felt we had been taking part in the battle ourselves.

A talk and demonstration by Jenkins and Storey was given on i4th February, entitled "Dyes and Dyeing." Jenkins spoke of the history of dyes and described how the dye industry had sprung up

from a few natural juices to the highly intricate modern system of dye synthesis. He used atomic models to illustrate the molecules of benzine, aniline, etc. He then discussed the various chemical combinations which are responsible for colour and those which are responsible for the adhesive power of the dye, leading on to the differences between cotton and wool dyeing. A mordant must be used in order that the dye may hold fast to the material. Jenkins explained the preparation of azo dyes and of dyes used for pigments in paper and paints, samples being prepared by Storey. Finally they dyed some fabrics, methyl violet giving especially good results. The meeting was concluded with questions from members.

Berg and Osborne, on 28th February, showed a film strip, with commentary, on "The World before the Coming of Man." The characteristic forms of life of the Palaeozoic, Mesozoic and Cainozoic eras, and in particular, the evolution of the horse, were described and illustrated. After a "technical hitch," the lecture was concluded by a series of cartoons of prehistoric animals drawn by Lawson Wood.

The fifth and last meeting necessitated an earlier start than usual in order to crowd everything in. Gibson, who gave an "Introduction to Tropical Fish," described the setting up of a tropical aquarium. He described several fishes and their breeding habits, including the guppy, the zebra fish and the three-spot gourans. Hannon's subject was "Queer Fish," and he described the climbing perch, mud skipper, angler fish, flying fish and archer fish. Both talks were illustrated by the episcope and lantern slides. A third talk, entitled "Bricks and Brickmaking," was given by Presswood. He began with a short description of early brickmaking and continued with a description of the different types of clay, illustrated by some specimens which he passed round. He went on to talk about heating the clays and the different types of bricks, several of which were broken to point out the effects of different temperatures upon them. He described the different types of brickmaking machines, and concluded the talk, on which he had spent much time and effort, by showing pictures and slides, some in colour, which he had taken himself.

A VISIT TO A PRINTING WORKS

Ten boys of the Science Society and two masters spent a very instructive and enjoyable afternoon on 2nd March, when we paid a visit to the works of Messrs. Ben. Johnson & Sons, designers, lithographers, and printers.

First we were shown examples of the firm's work. We saw many sorts of illustrated catalogues, prospectuses (including one of this School), and beautiful reproductions of religious pictures. All such work is of very high quality and goes all over the world.

We were then split up into two parties, one of which went first to the typographical department. The oldest kind of type, hand-set, 26

is largely dropping out of use, nowadays, as it takes too long to set individual letters. The next method we saw is much more rapid. A whole line of type is set up by an amazingly ingenious machine, known as a "linotype," which moulds the letters from molten type metal, an alloy of lead, copper and antimony. For tables of figures and statistics, monotype is used. A small machine, resembling a typewriter, punches holes on a drum of paper. This paper is used for setting the type, in a similar fashion to the way in which a perforated sheet of paper is used in a pianola for producing sounds. Lines of type are set up in a frame, called a chase. A sheet of a special material like papier mache, called a flong, is pressed against the chase, and the flong receives an impression, in reverse, of the type. The flong now acts as a mould for molten type metal, which, when set, is placed in the printing press. This smears ink over the surface of the type and prints the impression on paper.

Lithography, as opposed to typography, is the printing of pictures, etc., from zinc plates upon which the design is placed photographically. The zinc plate is first given a grain by the agitation of marbles which scratch the surface. It is then covered with a thin even film of egg albumen. The photographic plate which bears an image is then placed over the zinc plate inside a vacuum case in order to ensure good contact. Strong light from an arc lamp is then allowed to fall on the zinc plate through the photographic negative. When the light strikes the zinc, the albumen hardens on to the surface, aided by the grain. Any albumen which remains unaffected is then washed off. Thus a positive image is prepared on the zinc plate. This is then damped and ink smeared over the surface. Ink does not adhere to the damp places where there is no albumen. If a piece of paper is now pressed against the zinc plate, it receives an impression of the design. A coloured object is photographed through various coloured filters, the images on the various negatives being different for each colour. These negatives are used to make zinc plates, the patterns on which therefore differ. Each zinc plate is used with the correct coloured ink and by superimposing the various coloured images, a reproduction of the original is obtained'. For ordinary work the four-colour process is employed, but for the highest quality work eight colours are used.

Unfortunately, lack of time prevented us from seeing the bookbinding department.

The firm is, at the moment, one of the few manufacturers of transfers, beloved of small boys, and the only manufacturers in Europe of coloured "scraps" which are popular with all children. Since products of the firm go all over the world, it is doing a great deal to earn dollars for us.

We are very grateful to Mr. Bernard Johnson for arranging this visit, which we regard as a very special favour.

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