The next day, the 17th of April, the sailor's first words were addressed to Gideon Spilett.

"Well, sir," he asked, "what shall we do to-day?"

"What the captain pleases," replied the reporter.

Till then the engineer's companions had been brickmakers and potters, now they were to become metallurgists.

The day before, after breakfast, they had explored as far as the point of Mandible Cape¹, seven miles distant from the Chimneys. There, the long series of downs ended, and the soil had a volcanic² appearance. There were no longer high cliffs as at Prospect³ Heights, but a strange and capricious border which surrounded the narrow gulf⁴ between the two capes⁵, formed of mineral matter, thrown up by the volcano. Arrived at this point the settlers retraced⁶ their steps, and at nightfall entered the Chimneys; but they did not sleep before the question of knowing whether they could think of leaving Lincoln Island or not was definitely settled.

The twelve hundred miles which separated the island from the Pomoutous Island was a considerable distance. A boat could not cross it, especially at the approach of the bad season. Pencroft had expressly declared this. Now, to construct a simple boat even with the necessary tools, was a difficult work, and the colonists⁷ not having tools they must begin by making hammers, axes, adzes, saws, augers, planes, etc., which would take some time. It was decided⁸, therefore, that they would winter at Lincoln Island, and that they would look for a more comfortable dwelling⁹ than the Chimneys, in which to pass the winter months.

Before anything else could be done it was necessary to make the iron ore, of which the engineer had observed some traces in the northwest part of the island, fit for use by converting it either into iron or into steel.

Metals are not generally found in the ground in a pure state. For the most part they are combined with oxygen or sulphur. Such was the case with the two specimens¹⁰ which Cyrus Harding had brought back, one of magnetic iron, not carbonated, the other a pyrite, also called sulphuret of iron. It was, therefore the first, the oxide¹² 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 smelts¹³ the ore, then changes it into iron, by carrying away the three to four per cent. of coal, which is combined with it.

Now Cyrus Harding wanted iron, and he wished to obtain it as soon as possible. The ore which he had picked up was in itself very pure and rich. It was the oxydulous iron, which is found in confused masses of a deep gray color; it gives a black dust, crystallized in the form of the regular octahedron. Native lodestones consist of this ore, and iron of the first quality is made in Europe from that with which Sweden and Norway are so abundantly supplied. Not far from this vein¹⁴ was the vein of coal already made use of by the settlers. The ingredients for the manufacture being close together would greatly facilitate the treatment of the ore. This is the cause of the wealth of the mines in Great Britain, where the coal aids the manufacture of the metal extracted from the same soil at the same time as itself.

"Then, captain," said Pencroft, "we are going to work iron ore?"

"Yes, my friend," replied the engineer, "and for that--something which will please you--we must begin by having a seal hunt on the islet."

"A seal hunt!" cried the sailor, turning towards Gideon Spilett. "Are seals needed to make iron?"

"Since Cyrus has said so!" replied the reporter.

But the engineer had already left the Chimneys, and Pencroft prepared for the seal hunt, without having received any other explanation.

Cyrus Harding, Herbert, Gideon Spilett, Neb, and the sailor were soon collected on the shore, at a place where the channel left a ford¹⁵ passable at low tide. The hunters could therefore traverse it without getting wet higher than the knee.

Harding then put his foot on the islet for the first, and his companions for the second time.

On their landing some hundreds of penguins¹⁶ looked fearlessly at them. The hunters, armed with sticks, could have killed them easily, but they were not guilty of such useless massacre¹⁷, as it was important not to frighten the seals, who were lying on the sand several cable lengths off. They also respected certain innocent-looking birds, whose wings were reduced to the state of stumps¹⁸, spread out like fins¹⁹, ornamented²⁰ with feathers of a scaly²¹ appearance. The settlers, therefore, prudently²² advanced towards the north point, walking over ground riddled²³ with little holes, which formed nests for the sea-birds. Towards the extremity²⁴ of the islet appeared great black heads floating just above the water, having exactly the appearance of rocks in motion.

These were the seals which were to be captured. It was necessary, however, first to allow them to land, for with their close, short hair, and their fusiform conformation, being excellent swimmers, it is difficult to catch them in the sea, while on land their short, webbed feet prevent their having more than a slow, waddling²⁵ movement.

Pencroft knew the habits of these creatures, and he advised waiting till they were stretched on the sand, when the sun, before long, would send them to sleep. They must then manage to cut off their retreat and knock them on the head.

The hunters, having concealed²⁶ themselves behind the rocks, waited silently.

An hour passed before the seals came to play on the sand. They could count half a dozen. Pencroft and Herbert then went round the point of the islet, so as to take them in the rear, and cut off their retreat. During this time Cyrus Harding, Spilett, and Neb, crawling behind the rocks, glided²⁷ towards the future scene of combat.

All at once the tall figure of the sailor appeared. Pencroft shouted. The engineer and his two companions threw themselves between the sea and the seals. Two of the animals soon lay dead on the sand, but the rest regained²⁸ the sea in safety.

"Here are the seals required, captain!" said the sailor, advancing towards the engineer.

"Capital," replied Harding. "We will make bellows²⁹ of them!"

"Bellows!" cried Pencroft. "Well! these are lucky seals!"

It was, in fact, a blowing-machine, necessary for the treatment of the ore that the engineer wished to manufacture with the skins of the amphibious creatures. They were of a medium size, for their length did not exceed six feet. They resembled a dog about the head.

As it was useless to burden themselves with the weight of both the animals, Neb and Pencroft resolved to skin them on the spot, while Cyrus Harding and the reporter continued to explore the islet.

The sailor and the Negro cleverly performed the operation, and three hours afterwards Cyrus Harding had at his disposal two seals' skins, which he intended to use in this state, without subjecting them to any tanning process.

The settlers waited till the tide was again low, and crossing the channel they entered the Chimneys.

The skins had then to be stretched on a frame of wood and sewn by means of fibers³¹ so as to preserve the air without allowing too much to escape. Cyrus Harding had nothing but the two steel blades from Top's collar, and yet he was so clever, and his companions aided him with so much intelligence, that three days afterwards the little colony's stock of tools was augmented³² by a blowing-machine, destined³³ to inject the air into the midst of the ore when it should be subjected to heat--an indispensable condition to the success of the operation.

On the morning of the 20th of April began the "metallic³⁴ period," as the reporter called it in his notes. The engineer had decided, as has been said, to operate near the veins³⁵ both of coal and ore. Now, according to his observations, these veins were situated³⁶ at the foot of the northeast spurs of Mount Franklin, that is to say, a distance of six miles from their home. It was impossible, therefore, to return every day to the Chimneys, and it was agreed that the little colony should camp under a hut of branches, so that the important operation could be followed night and day.

This settled, they set out in the morning. Neb and Pencroft dragged the bellows on a hurdle³⁷; also a quantity of vegetables and animals, which they besides could renew on the way.

The road led through Jacamar Wood, which they traversed obliquely³⁸ from southeast to northwest, and in the thickest part. It was necessary to beat a path, which would in the future form the most direct road to Prospect Heights and Mount Franklin. The trees, belonging to the species already discovered, were magnificent. Herbert found some new ones, among others some which Pencroft called "sham³⁹ leeks"; for, in spite of their size, they were of the same liliaceous family as the onion, chive, shallot, or asparagus. These trees produce ligneous⁴⁰ roots which, when cooked, are excellent; from them, by fermentation, a very agreeable liquor is made. They therefore made a good store of the roots.

The journey through the wood was long; it lasted the whole day, and so allowed plenty of time for examining the flora⁴¹ and fauna⁴². Top, who took special charge of the fauna, ran through the grass and brushwood, putting up all sorts of game. Herbert and Gideon Spilett killed two kangaroos with bows and arrows, and also an animal which strongly resembled both a hedgehog and an ant-eater. It was like the first because it rolled itself into a ball, and bristled⁴³ with spines⁴⁴, and the second because it had sharp claws, a long slender snout which terminated in a bird's beak⁴⁵, and an extendible tongue, covered with little thorns which served to hold the insects.

"And when it is in the pot," asked Pencroft naturally, "what will it be like?"

"An excellent piece of beef," replied Herbert.

"We will not ask more from it," replied the sailor,

During this excursion they saw several wild boars, which however, did not offer to attack the little band, and it appeared as if they would not meet with any dangerous beasts; when, in a thick part of the wood, the reporter thought he saw, some paces from him, among the lower branches of a tree, an animal which he took for a bear, and which he very tranquilly⁴⁶ began to draw. Happily for Gideon Spilett, the animal in question did not belong to the redoubtable⁴⁷ family of the plantigrades. It was only a koala, better known under the name of the sloth⁴⁸, being about the size of a large dog, and having stiff hair of a dirty color, the paws armed with strong claws, which enabled it to climb trees and feed on the leaves. Having identified the animal, which they did not disturb, Gideon Spilett erased⁴⁹ "bear" from the title of his sketch⁵⁰, putting koala in its place, and the journey was resumed.

At five o'clock in the evening, Cyrus Harding gave the signal to halt. They were now outside the forest, at the beginning of the powerful spurs which supported Mount Franklin towards the west. At a distance of some hundred feet flowed the Red Creek⁵¹, and consequently plenty of fresh water was within their reach.

The camp was soon organized. In less than an hour, on the edge of the forest, among the trees, a hut of branches interlaced with creepers, and pasted over with clay, offered a tolerable shelter. Their geological researches were put off till the next day. Supper was prepared, a good fire blazed before the hut, the roast turned, and at eight o'clock, while one of the settlers watched to keep up the fire, in case any wild beasts should prowl in the neighborhood, the others slept soundly.

The next day, the 21st of April, Cyrus Harding accompanied by Herbert, went to look for the soil of ancient formation, on which he had already discovered a specimen¹¹ of ore. They found the vein above ground, near the source of the creek, at the foot of one of the northeastern spurs. This ore, very rich in iron, enclosed in its fusible veinstone, was perfectly⁵² suited to the mode of reduction which the engineer intended to employ; that is, the Catalan method, but simplified, as it is used in Corsica. In fact, the Catalan method, properly so called, requires the construction of kilns⁵³ and crucibles⁵⁶, in which the ore and the coal, placed in alternate layers, are transformed and reduced, But Cyrus Harding intended to economize⁵⁷ these constructions, and wished simply to form, with the ore and the coal, a cubic mass, to the center of which he would direct the wind from his bellows. Doubtless, it was the proceeding⁵⁸ employed by Tubalcain, and the first metallurgists of the inhabited world. Now that which had succeeded with the grandson of Adam, and which still yielded good results in countries which in ore and fuel, could not but succeed with the settlers in Lincoln Island.

The 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 cleansed⁵⁹ them with the hand from the impurities⁶⁰ which soiled their surface. Then coal and ore were arranged in heaps and in successive 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.

Thus the engineer proceeded. The bellows of sealskin, furnished at its extremity with a nozzle of clay, which had been previously⁶¹ fabricated in the pottery⁶² kiln⁵⁴, was established near the heap of ore. Using the mechanism⁶³ which consisted of a frame, cords of fiber³⁰ and counterpoise, he threw into the mass an abundance of air, which by raising the temperature also concurred⁶⁴ with the chemical transformation⁶⁵ to produce in time pure iron.

The operation was difficult. All the patience, all the ingenuity⁶⁶ of the settlers was needed; but at last it succeeded, and the result was a lump of iron, reduced to a spongy state, which it was necessary to shingle⁶⁷ and fagot, that is to say, to forge so as to expel from it the liquefied veinstone. These amateur smiths had, of course, no hammer; but they were in no worse a situation than the first metallurgist, and therefore did what, no doubt, he had to do.

A handle was fixed⁶⁸ to the first lump, and was used as a hammer to forge the second on a granite⁶⁹ anvil⁷⁰, and thus they obtained a coarse but useful metal. At length, after many trials and much fatigue⁷¹, on the 25th of April several bars of iron were forged, and transformed into tools, crowbars, pincers, pickaxes, spades, etc., which Pencroft and Neb declared to be real jewels. But the metal was not yet in its most serviceable state, that is, of steel. Now steel is a combination of iron and coal, which is extracted, either from the liquid ore, by taking from it the excess of coal, or from the iron by adding to it the coal which was wanting. The first, obtained by the decarburation of the metal, gives natural or puddled steel; the second, produced by the carburation of the iron, gives steel of cementation.

It was the last which Cyrus Harding intended to forge, as he possessed⁷² iron in a pure state. He succeeded by heating the metal with powdered coal in a crucible⁵⁵ which had previously been manufactured from clay suitable for the purpose.

He then worked this steel, which is malleable⁷³ both when hot or cold, with the hammer. Neb and Pencroft, cleverly directed, made hatchets⁷⁴, which, heated red-hot, and plunged⁷⁵ suddenly into cold water, acquired an excellent temper.

Other instruments, of course roughly fashioned, were also manufactured; blades for planes, axes, hatchets, pieces of steel to be transformed into saws, chisels⁷⁶; then iron for spades, pickaxes, hammers, nails, etc. At last, on the 5th of May, the metallic period ended, the smiths returned to the Chimneys, and new work would soon authorize⁷⁷ them to take a fresh title.

第二天4月17日，水手第一句话是对吉丁.史佩莱说的。

“先生，”他问道，“今天我们干什么？”

“赛勒斯先生说干什么就干什么。”通讯记者答道。

在前一个时期，工程师的伙伴们不是制砖工人就是陶器工人，现在他们要变成冶金工人了。

昨天早饭以后，他们一直走到离“石窟”七英里的颚骨角，连绵不绝的沙丘到头了。那里的土壤看起来好象是火山土，没有象眺望岗那样的悬崖峭壁，只有一种火山喷发出来的奇形怪状的矿物质，在两个海角中间形成狭长海湾的边缘。居民们来到这里以后，就往回走了。暮色苍茫的时候，他们回到了“石窟”，可是他们想到能不能离开林肯岛的问题还没有肯定，就睡不着觉了。

海岛离帕摩图群岛一千二百英里，这是一段相当遥远的距离。一只小船是没法渡过去的，再说，已经快到寒冷的季节了。潘克洛夫特别强调这一点。即使有必要的工具，要造一只小船也很艰巨，何况移民们还没有工具，他们必须先开始做锤、斧、锛、锯、钻、刨等等，这需要一段相当长的时间。因此他们决定在林肯岛上过冬，并且要找一个比“石窟”舒服一些的地方避寒。

首先必须要找铁矿，工程师曾在海岛的西北部发现这种蕴藏，这种铁矿既适合炼钢，又适合炼铁。

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.史密斯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。

现在，赛勒斯.史密斯需要铁，而且想尽早炼出来。他所捡到的铁矿石质地非常优良纯粹，是一种氧化铁。在捡来的时候，它是不规则的深灰色的大块，从中可以得到一种正八面结晶体形成的黑色碎末。天然的磁石里就含有这种矿石，瑞典和挪威大量出产这种原料，在那里把它炼成了欧洲最好的生铁。离这个矿脉不远就是煤层，居民们已经利用过这里的煤了。炼铁需要的原料就在附近，这就给工作带来极大的便利。英国的矿藏所以宝贵，就是因为从地下可以同时开采出煤和金属来进行冶炼的缘故。

“那么，史密斯先生，”潘克洛夫说，“我们这就要炼铁了吗？”

“是的，朋友，”工程师答道，“为了这一点，我们首先要进行一样你所喜欢的工作——到小岛上去打海豹。”

“打海豹！”水手掉过脸来对吉丁.史佩莱说，“炼铁需要海豹吗？”

“既然赛勒斯这么说，那就不会错！”通讯记者答道。

工程师已经离开“石窟”了，别人又解答不了这个问题，潘克洛夫只好准备去打海豹。

赛勒斯.史密斯、赫伯特、吉丁.史佩莱、纳布和水手很快就在岸边集合，退潮的时候，这一带海峡形成一条浅滩可以通行，猎人们涉水过去，水深还不到膝盖。

史密斯还是第一次到小岛上来，他的伙伴们已经是第二次了。当初，气球就是把他们扔在这个地方的。

他们上岸的时候，有几百只企鹅望着他们，一点也不害怕。猎人们手里拿着棍子，本来很容易把它们打死，但这时候还不能无端杀害它们，因为海豹正躺在几锚链以外的沙滩上，不能把它们惊动了。还有一种鸟，样子很老实，它们的翅膀已经退化成短肢，象鳍似的往两边张开，浑身的羽毛和鳞片一样。居民们也没有侵犯它们。地面上到处是小洞，海鸟就在洞里做了窝。他们悄悄地穿过这一带往北走去。小岛尽头一带的水面上有许多黑色的大脑袋漂浮着，好象岩石在移动。

这就是他们打算猎捕的海豹，但是要想捉它们，首先必须等它们上岸，因为它们长着细密的短毛和纱锭似的躯体，在水里游起来非常快，想在海里捉住它是很困难的，在陆地上，由于它们的蹼足短小，它们只能摇摇摆摆地慢步走动。

潘克洛夫知道这种动物的习性，他教大家等着，海豹会到沙滩上来晒太阳的，而且一会儿就会躺下睡熟。那时候再切断它们的归路，打它们的头部。

猎人们躲在岩石后面，静静地等待着。

一个钟头以后，海豹到沙滩上来玩耍了。上来的有半打。潘克洛夫和赫伯特绕过小岛的海角，切断它们的后路，从后面向它们进攻。这时候赛勒斯.史密斯、史佩莱和纳布也从石头后边爬了出来，向即将成为战场的地方溜去。

水手高大的身材忽然站起来了。他大吼一声。工程师和他的两个伙伴马上跑过去站在大海和海豹之间。一会儿工夫，就有两只海豹死在地上了。可是其他的几只却平平安安地逃回了大海。

“史密斯先生，你不是要海豹吗，现在打到了！”水手一面说，一面向工程师走去。

“好极了，”史密斯答道。“我们要拿它们做风箱！”

“风箱！”潘克洛夫喊道，“怎么！这些海豹的命运倒不错呀！”

原来工程师打算用这种两栖动物的皮来做冶炼时不可缺少的鼓风机。这两个海豹大小普通，身长不满六英尺。它们的头部和狗的脑袋很象。

如果把两只海豹抬回去，既费力，又没有用，因此纳布和潘克洛夫决定就在这里剥它们的皮，赛勒斯.史密斯和通讯记者利用这个时间巡视小岛去了。

水手和黑人剥得非常巧妙，三个钟头以后，赛勒斯.史密斯就得到了两整张海豹皮，他打算不加鞣制，就这样使用。

等到潮水再度下退的时候，居民们就涉过海峡，回“石窟”来了。

然后，他们就把海豹皮绷在木架上，用纤维把它缝起来，尽量使它不漏气。赛勒斯.史密斯除了用托普的套环做成两片钢刀以外，其他什么工具也没有。然而他非常有办法，发挥了伙伴们无穷的智慧，三天以后，小队的工具就又增添了一件鼓风机了，在矿石加热的时候，用这个工具往矿石里送风——这是争取胜利完成冶炼工作的一个不可缺少的条件。

4月20日清晨，正如通讯记者所记载的，“金属时代”开始了。前面已经说过，工程师决定在邻近煤矿和铁矿的地方进行操作。根据他的观察，矿脉在富兰克林山东北支脉的山麓。这地方离“石窟”六英里，每天往返回家是不可能的。因此，小队一致决定用树枝搭一个棚子过夜，这样，他们就可以昼夜不停地进行这项重要的工作了。

早晨，这个问题决定以后，他们就出发了。纳布和潘克洛夫找了一个筐子，把风箱放在上面拖着走，另外还在筐上放了大量的蔬菜和兽肉，除了所带的以外，他们还准备沿途补充一些。

途中要经过啄木鸟林，他们从东南进入丛林，经过树木最密的地方，往西北方斜穿出去。他们必须开辟一条道路，将来这条道路可以把眺望岗和富兰克林山直接联系起来。有许多非常美丽的植物，它们的品种都是大家熟悉的。赫伯特又发现一些新的品种，其中有的潘克洛夫把它们叫做“假韭菜”；因为虽然比韭菜大得多，却也和洋葱、日本葱、冬葱和芦笋一样，属于百合科。这些植物长有木质的根，烧出来非常好吃。这些根经过发酵以后，还可以制成一种非常可口的饮料。因此他们大量地采集了这种树根。

他们在森林里走了很长的一段路，整整走了一天，因此有充分的时间观察林中的动植物。托普专门搜寻兽类，它在草木之间穿进穿出，把各种动物全赶出来了。赫伯特和吉丁.史佩莱用弓箭射死两只袋鼠，还射死一只既很象刺猬，又很象食蚁兽的动物。从它缩成一团、满身刺针倒竖的样子看来好象刺猬，它长着利爪，嘴部又细又长，末端跟鸟嘴一样，这又很象食蚁兽；另外它还有一根伸缩灵活的舌头，舌头上有很多小刺，可以用来捕食昆虫。

“等它下了锅以后，”潘克洛夫照例这样问道，“它象什么？”

“象最好的牛肉。”赫伯特答道。

“好，我们也不能要求过高了。”水手说。

在旅途中，他们看见几次野猪，可是这些野猪并没有向小队冲来，看来他们好象不会遇见什么猛兽了，可是这时候通讯记者隐约看见在几步以外浓密的树丛中，有一只野兽伏在一棵树的低枝间。他以为那是一只熊，就开始非常镇定地把它画下来。幸而这只动物并不属于可怕的蹠行类，它只是一只无尾熊，一般称为“懒兽”，体形和较大的狗差不多，身上的毛既硬又显得脏，脚上生着有力的爪子，能够攀登树木，它平时吃树叶。他们认清了这个动物，也没有侵犯它。吉丁.史佩莱把写生画的标题“熊”擦去，改成“无尾熊”，然后大家就继续前进了。

傍晚五点钟，赛勒斯.史密斯下令大家停下来。他们现在已经穿过森林，来到作为富兰克林山东部基础的主要支脉下。红河在几百英尺以外的地方流过，附近可以得到大量的淡水。

营地马上就安排好了。不到一个小时，他们就在森林边缘的树木之间，用爬藤把树枝编起来，搭成一个营棚，外面抹上一层泥土，这样就建成一个不坏的住处了。他们的地质勘探工作预定到第二天再进行。现在营棚前生起了一堆熊熊的篝火，烤肉在火焰上转动着。晚饭准备好了，八点钟的时候，大家都已睡下，只留一个人守夜，不使篝火熄灭，以防野兽潜到营地附近来。

第二天，4月21日，赛勒斯.史密斯让赫伯特随同一道去找古代生成的土层，上一次他已经在这种土地上发现了铁矿石的标本。他们在东北的一个支脉下发现矿脉，这个地方靠近红河发源地，而且矿石就露在地面上。这种矿石容易熔化，含铁量也很大，非常适合工程师打算采用的还原炼铁法，也就是加泰罗尼亚人用的土法，不过象科西嘉人那样把这种方法简化了。一般所说的土法，需要砌个熔炉，制造几个坩埚，把矿石和炭一层夹一层地放在坩埚里，然后让它变化和还原。可是赛勒斯.史密斯不打算用这些设备，只想把矿石和煤做成一个立方体，用风箱把空气鼓入立方体的中心。毫无疑问，这是土八.该隐以及世界上最早的冶金学家所采用的办法。既然亚当的子孙用这个方法能够成功，而且在铁矿和燃料丰富的国家里也曾收到良好的效果，那么林肯岛上的居民也一定会成功的。

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。

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。

工作是艰巨的，需要居民们最大的耐心和全部的智慧。最后终于成功了，炼出一块和海绵差不多的生铁，这块生铁还要加以锤炼，也就是说，必须经过打铁，把熔解的杂质排除出去。当然，这些业余铁匠是没有锤子的，可是他们的情况并不见得比最早的冶金家更坏，因此他们就模仿前辈的样子干起来了。

他们给一块生铁按上木柄，当作锤子，把花岗石当作砧子，就这样打起铁来。他们打出来的铁，虽然粗糙一些，却很有用。经过无数次的艰苦尝试，终于在4月25日打出了几根铁条，用它们做成许多工具，如铁橇、钳子、鹤嘴锄、铲子等等。潘克洛夫和纳布拿着这些工具，兴奋得象得了宝贝似的。

可是这种金属还没有达到尽善尽美的程度，也就是说还没有变成钢。钢是铁和炭的混合物。要取得钢，必须从生铁里除去多余的炭，或是把一定数量的炭加到熟铁里去才行。第一种脱炭的方法可以产生天然钢或是铸钢，第二种加炭的方法可以制成有泡钢。

赛勒斯.史密斯打算炼制后面一种，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。

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。

还有许多其他工具也制造出来了，形状自然是非常简陋的，其中有：做刨刀、砍柴斧、短斧用的钢板，做锯和凿子用的钢块；此外还有制造铲子、鹤嘴锄、锤子、钉子用的铁等等。5月5日那天，“金属时期”终于结束了。铁匠们回到“石窟”里，很快就要有新的工作给他们加上新的头衔了。