英國學(xué)生科學(xué)讀本 Lesson 37 關(guān)于便士(1)
第37課 關(guān)于便士
When I was a little boy, pennies, and halfpennies, and farthings were made of pure copper. But copper is too soft a metal to stand the rubbing which coins get. So these old pennies soon became so smooth that one could not tell "head"from "tail, " or indeed see any letters on the pennies at all.
我還是個(gè)小男孩的時(shí)候， 英國的便士、半便士、四分之一便士硬幣， 都是純銅做的。可是純銅這種金屬太軟， 硬幣在使用中磨得太厲害， 純銅經(jīng)不起這種摩擦。所以， 這些老硬幣很快就會磨得太光， 連正反面都看不出來， 便士上的字母更是磨得一個(gè)也看不見了。
By mixing with the copper a little of each of the two other metals known as zinc and tin, we get an alloy called bronze. Any mixture of two or more metals is named an alloy. Bronze is much harder than the copper alone, or the zinc alone, or the tin alone.
有兩種金屬名叫“鋅”和“錫”， 如果在銅里， 把這兩種金屬中的一種， 摻一點(diǎn)兒進(jìn)去， 我們就得到了一種叫做“青銅”的合金。合金， 就是兩種或者更多種金屬的混合物， 青銅比單獨(dú)的銅、單獨(dú)的鋅、單獨(dú)的錫都硬得多。
The melted bronze is poured into moulds, and is thus cast into bars about a foot long. Next, each of these bars is rolled out between steel rollers, and made into a sheet of metal of the thickness of a penny.
青銅熔化之后， 倒進(jìn)模具里面， 鑄成大約一英尺長的青銅條。然后， 把這些青銅條放在鋼制的滾筒之間， 壓成一便士那么厚的金屬板。
A machine then cuts the sheet of bronze into round pieces, called blanks, each being just the size of a penny.Then each blank has its edge thickened by another machine. The thickened edge keeps the letters on the coin from being worn off.
然后， 一臺機(jī)器把青銅板切成圓形的小塊， 這些小塊叫做“坯餅”， 每一個(gè)坯餅的尺寸都和一個(gè)硬幣的尺寸相當(dāng)。然后， 每一個(gè)坯餅的邊緣， 再用另一臺機(jī)器加厚。加厚的邊緣， 可以防止硬幣上的字母磨掉。
But now the letters and the figures must be put on.
但是， 現(xiàn)在就必須往硬幣上印字母和數(shù)字了!
