第66章 知识（2/2）

&nbsp&nbsp&nbsp&nbsp他们利用木杆量出了两段水平距离，木杆在沙滩上的高度是十英尺整。第一段距离是从小棍子到插木杆的地方，相距十五英尺。第二段距离是从小棍子到峭壁底部，相距五百英尺。

&nbsp&nbsp&nbsp&nbsp15:500＝10:X

&nbsp&nbsp&nbsp&nbsp500×10＝5000

&nbsp&nbsp&nbsp&nbsp6000÷15＝333.3

&nbsp&nbsp&nbsp&nbsp由此得出，岗石峭壁的高度是三百三十三英尺。

&nbsp&nbsp&nbsp&nbspThe two horizontal distances were found out by means of the pole， whose length above the sand was exactly ten feet.

&nbsp&nbsp&nbsp&nbspThe first distance was fifteen feet between the stick and the place where the pole was thrust into the sand.

&nbsp&nbsp&nbsp&nbspThe second distance between the stick and the bottom of the cliff was five hundred feet. From which it was proved that the granite cliff measured 333 feet in height.

&nbsp&nbsp&nbsp&nbsp圆规两脚之间的距离就是十字架二和水平线之间的角距。他首先把一个圆周分成三百六十等分，然后非常精确地把圆规角度落在圆周上，得出的结果是10度。在这个角度上加上十字架二距离南极的27度，再减去观察的时候所在的峭壁上离海面高度的值，就得出一个37度的角来。南极与水平线之间相距90度，从90度里减去53度还剩下37度。因此，赛勒斯?哈顿测量的结论是：林肯岛在南纬37度线上。如果把计算时不精确的程度估计在内，假设误差有五度，那么海岛的位置一定在南纬35度与40度之间。

&nbsp&nbsp&nbsp&nbsp然后赛勒斯?哈顿就把前一天晚上做的仪器拿了出来，圆规两脚之间的距离就是十字架二和水平线之间的角距。他首先把一个圆周分成三百六十等分，然后非常精确地把圆规角度落在圆周上，得出的结果是10度。在这个角度上加上十字架二距离南极的27度，再减去观察的时候所在的峭壁上离海面高度的值，就得出一个37度的角来。南极与水平线之间相距90度，从90度里减去53度还剩下37度。因此，赛勒斯?哈顿测量的结论是：林肯岛在南纬37度线上。如果把计算时不精确的程度估计在内，假设误差有五度，那么海岛的位置一定在南纬35度与40度之间。

&nbsp&nbsp&nbsp&nbspCyrus Harding then took the instrument which he had made the evening before， the space between its two legs giving the angular distance between the star Alpha and the horizon. He measured， very exactly， the opening of this angle on a circumference which he divided into 360 equal parts. Now， this angle by adding to it the twenty-seven degrees which separated Alpha from the antarctic pole， and by reducing to the level of the sea the height of the cliff on which the observation had been made， was found to be fifty- three degrees. These fifty-three degrees being subtracted from ny degrees--the distance from the pole to the equator--there remained thirty- seven degrees. Cyrus Harding concluded， therefore， that Lincoln Island was situated on the thirty-seventh degree of the southern latitude， or taking into consideration through the imperfection of the performance， an error of five degrees， that it must be situated between the thirty-fifth and the fortieth parallel.

&nbsp&nbsp&nbsp&nbsp按道理，当影子的长度缩到最短的时候，应该正是中午十二点钟，仔细地看着影子的末端，就可以找出影子在逐渐缩短以后，又开始伸长的一刹那。赛勒斯?哈顿把标杆偏向和太阳相对的方向，就可以使影子长一些，因此它的变化就更加容易看清了。日晷的时针愈长，针点的移动也就愈加容易辨别。标杆的影子也就相当于日晷上的指针。

&nbsp&nbsp&nbsp&nbspIn fact， the essively diminished， it began to lengthen. By inclining his stick to the side opposite to the sun， Cyrus Harding made the shadow longer， and consequently its modifications would be more easily ascertained. In fact， the longer the needle of a dial is， the more easily can the movement of its point be followed. The shadow of the stick was nothing but the needle of a dial.

&nbsp&nbsp&nbsp&nbsp一般的情况下，金属埋藏在地里的时候，质地并不纯粹。它们通常和氧或硫化合在一起。赛勒斯?哈顿上次带回来的两种标本就是这样，一种是没有碳化的磁铁矿，另一种是黄铁矿，也叫做硫化铁。因此，他们必须先用炭使氧化铁还原，也就是除去氧，然后才能得到纯粹的铁。这个还原过程是用炭把矿石烧到温度很高的时候进行的，可以用迅速而简便的土法（它的优点是只通过一道工序，就能把铁矿石炼成铁），也可以用鼓风炉——第一步使铁矿石熔化，然后排除和矿石化合在一起的百分之三至四的炭，使它变成铁。

&nbsp&nbsp&nbsp&nbspMetals are not generally found in the ground in a pure state. For the most part they arebined with oxygen or sulphur. Such was the case with the two specimens which Cyrus Harding had brought back， one of maic iron， not carbonated， the other a pyrite， also called sulphuret of iron. It was， therefore the first， the oxide of iron， which they must reduce with coal， that is to say， get rid of the oxygen， to obtain it in a pure state. This reduction is made by subjecting the ore with coal to a high temperature， either by the rapid and easy Catalan method， which has the advantage of transforming the ore into iron in a single operation， or by the blast furnace， which first smelts the ore， then changes it into iron， by carrying away the three to four per cent. of coal， which isbined with it.

&nbsp&nbsp&nbsp&nbsp他们在地上毫不费力地捡到炭和铁矿石。他们先把铁矿石打碎，用手把铁矿石表面一层杂质擦干净，然后就把炭和铁矿石一层夹一层地堆起来，好象木炭工人用木柴烧炭那样。这样，在鼓风机的作用下，炭就变为碳酸，然后又变成氧化碳，在变成氧化碳的过程中就使氧化铁还原，放出了氧气。

&nbsp&nbsp&nbsp&nbsp工程师就这样进行工作。他事先在窑里造了一根陶土的管子，把它装在海豹皮风箱的一端，然后把风箱装在矿石堆附近，工程师用一个木架、一些植物纤维做的绳子和一个秤锤做成鼓风机，把大量的空气吹到立方体里去，温度提高以后，空气也促进化学变化，到一定的时候就能冶炼出纯铁来。

&nbsp&nbsp&nbsp&nbspThe coal， as well as the ore， was collected without trouble on the surface of the ground. They first broke the ore into little pieces， and cleansed theessive layers， as the charcoal-burner does with the wood which he wishes to carbonize. In this way， under the influence of the air projected by the blowing-machine， the coal would be transformed into carbonic acid， then into oxide of carbon， its use being to reduce the oxide of iron， that is to say， to rid it of the oxygen.

&nbsp&nbsp&nbsp&nbspThus the engineer proceeded. The bellows of sealskin， furnished at its extremity with a nozzle of clay， which had been previously fabricated in the pottery kiln， was established near the heap of ore. Using the mechanism which consisted of a frame， cords of fiber and counterpoise， he threw into the mass an abundance of air， which by raising the temperature also concurred with the chemical transformation to produce in time pure iron.

&nbsp&nbsp&nbsp&nbsp赛勒斯?哈顿打算炼制后面一种，因为他炼得的铁质地很纯。为了进行这项工作，他事先用陶土做了一个坩埚，把铁和炭末一起放在坩埚里加热，结果钢就炼成了。

&nbsp&nbsp&nbsp&nbsp这种钢不论在冷或热的情况下，都能任人摆布，于是他就用锤子在钢上进行加工。纳布和潘克洛夫在他精明指导下，把钢烧红了，然后突然浸入水中，制得了许多硬度很强的斧头。

&nbsp&nbsp&nbsp&nbspIt was the last which Cyrus Harding intended to forge， as he possessed iron in a pure state. He succeeded by heating the metal with powdered coal in a crucible which had previously been manufactured from clay suitable for the purpose.

&nbsp&nbsp&nbsp&nbspHe then worked this steel， which is malleable both when hot or cold， with the hammer. Neb and Pencroft， cleverly directed， made hatchets， which， heated red-hot， and plunged suddenly into cold water， acquired an excellent temper.

&nbsp&nbsp&nbsp&nbsp建桥是目前最迫切的工程。他们砍伐选好的树木，除去杈枝，做成横梁、托架和厚板。这座桥，在感恩河右岸的一头是固定的，而在左岸的一头却是活动的，这样就可以通过平衡力量方式把它吊升起来，正如某些闸桥那样。。

&nbsp&nbsp&nbsp&nbsp这项工程当然是相当艰巨的，虽然领导有方，还是了不少的时间，因为慈悲河在这里宽达八十英尺。必须在河床中打下一些桥桩，才能支撑桥板，为了打桩，就必须安装打桩机。桥桩应该形成两个弓架结构，使桥身能够承受重量。

&nbsp&nbsp&nbsp&nbspThe bridge was the most urgent work. Trees were selected， cut down， stripped of their branches， and cut into beams， joists， and planks. The end of the bridge which rested on the right bank of the Mercy was to be firm， but the other end on the left bank was to be movable， so that it might be raised by means of a counterpoise， as some canal bridges are managed.

&nbsp&nbsp&nbsp&nbspThis was certainly a considerable work， and though it was skillfully conducted， it took some time， for the Mercy at this place was eighty feet wide. It was therefore necessary to fix piles in the bed of the river so as to sustain the floor of the bridge and establish a pile-driver to act on the tops of these piles， which would thus form two arches and allow the bridge to support heavy loads.

&nbsp&nbsp&nbsp&nbsp很快，塞勒斯.哈顿要动手制造玻璃的一切条件都具备了。最难制造的工具就是吹玻璃的吹管，这是一种五六英尺长的铁管，它的一端用来蘸液体玻璃。潘克洛夫把一条簿薄的铁片卷成枪筒形，也就做成了一根随时可以使用的吹管了。

&nbsp&nbsp&nbsp&nbsp3月28日，炉子已被烧制灼热。他们在一百分沙粒，三十五分白垩，四十分硫酸钠里掺了两三分煤屑，就构成了那种制玻璃用的物质，混和在一起放在坩埚里。当炉里的高温使原料化为液体的时候，更确切地说变成胶状物时，赛勒斯?哈顿就用吹管蘸了一些，他在预先准备好的一块金属板上滚了滚吹管，做出一个适合于吹的形状来，然后把吹管递给赫伯特，教他吹另外的一端。

&nbsp&nbsp&nbsp&nbspThe tool， the eeded in making a tube soon ready for use.

&nbsp&nbsp&nbsp&nbspOn the 28th of March the tube was heated. A hundred parts of sand， thirty-five of chalk， forty of sulphate of soda， mixed with two or three parts of powdered coal，posed the substance， which was placed in crucibles. When the high temperature of the oven had reduced it to a liquid， or rather a pasty state， Cyrus Harding collected with the tube a quantity of the paste: he turned it about on a metal plate， previously arranged， so as to give it a form suitable for blowing， then he passed the tube to Herbert， telling him to blow at the other extremity.