2017-10-25
1378
Iron - Smelting without Charcoal
The First Blast Furnaces
So far, no furnace in Europe had been hot enough to melt iron to a liquid state. All that could be produced was a ‘spongy’ mass from which impurities had to be hammered out. However, design of furnaces improved over the centuries, and about the year 1400 very efficient blast furnaces were introduced by the Germans. They had found that a blast of air from water-powered bellows increased the temperature, though the iron still did not liquify. It became soft and spongy, worked its way down through the burning charcoal, and collected at the bottom of the furnace.
Furnaces were usually built about ten or fifteen feet high, but to economise on fuel a new one was built thirty feet high. Although the internal temperature in this was no higher, the iron arrived at the bottom in a completely liquid state. Not only could the metal be run off into moulds, but many of the impurities (which had previously to be hammered out) separated automatically from the melted iron. The reason for this tremendous stride in metallurgy was simple: the height of the furnace. The soft ‘sponge’ iron took so long to seep down through the charcoal that it absorbed a great deal of carbon. It became carburised, and as the melting point of carburised iron is 350o C less than ‘sponge’ iron, it became liquid.
By about the year 1600, iron production in Britain was beginning to suffer from lack of fuel. For 3,000 years all iron-smelting, both here and abroad, had been done with charcoal. Charcoal is partly-burned wood. In Britain, timber was running short and it was impossible for the iron-makers to equal the output of a country such as Sweden, where timber was abundant.
Вариант 8
1. Поставьте предложения в страдательный залог (Образец: Mother waters the flowers in the evening. — The flowers are watered in the evening (by mother). Переведите исходное предложение и предложение в страдательном залоге.
1. Julius Caesar called England Albion because of the white cliffs on the English coast. 2. They will produce different agricultural products on their farm. 3. The plant's research laboratory is developing new alloys for an important experiment. 4. Green Grass and beautiful flowers cover the ground in spring in our place. 5. Students of our group often visit History and Art Museums in our town.
2. Раскройте скобки, употребляя глаголы в Active или Passive Voice. Переведите предложения.
1. They (showed/were shown) many places of interest in Moscow during their last visit. 2. One (will build/will be built) a new metro station next year. 3. Tourists (are admiring/are being admired) Moscow University on the Lenin Hills now.4. The laboratory assistants (were asked/asked) for a new experiment to equip. 5.Newton (founded/was founded) higher mathematics by working out the calculus.
3. Раскройте скобки, употребляя глаголы в Passive Voice. Переведите предложения.
1. The man (to run) over by a motor-car. 2. Your clothes (to looked) after. 3. She (to hand) an important message by Oleg next week. 4. Professor N (to send) for by a first year student already. 5. We (to ask) many questions by the teacher now.
Переведите текст на русский язык. Выпишите предложения в страдательном залоге, подчеркните сказуемое, укажите время сказуемого, пользуясь таблицей «Времена в страдательном залоге»
