按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
this operation； catastrophes were prevented。 Sometimes the 'monk' was injured or killed in his work； then another took his place。 This was done in all mines until the Davy lamp was universally adopted。 But I knew the plan； and by its means I discovered the presence of firedamp and consequently that of a new seam of coal in the Dochart pit。〃
All that the old overman had related of the so…called 〃monk〃 or 〃fireman〃 was perfectly true。 The air in the galleries of mines was formerly always purified in the way described。
Fire…damp； marsh…gas； or carburetted hydrogen； is colorless； almost scentless； it burns with a blue flame； and makes respiration impossible。 The miner could not live in a place filled with this injurious gas； any more than one could live in a gasometer full of mon gas。 Moreover； fire…damp； as well as the latter； a mixture of inflammable gases； forms a detonating mixture as soon as the air unites with it in a proportion of eight； and perhaps even five to the hundred。 When this mixture is lighted by any cause； there is an explosion； almost always followed by a frightful catastrophe。
As they walked on； Simon Ford told the engineer all that he had done to attain his object； how he was sure that the escape of fire…damp took place at the very end of the farthest gallery in its western part； because he had provoked small and partial explosions； or rather little flames； enough to show the nature of the gas； which escaped in a small jet； but with a continuous flow。
An hour after leaving the cottage； James Starr and his two panions had gone a distance of four miles。 The engineer； urged by anxiety and hope； walked on without noticing the length of the way。 He pondered over all that the old miner had told him； and mentally weighed all the arguments which the latter had given in support of his belief。 He agreed with him in thinking that the continued emission of carburetted hydrogen certainly showed the existence of a new coal…seam。 If it had been merely a sort of pocket； full of gas； as it is sometimes found amongst the rock； it would soon have been empty； and the phenomenon have ceased。 But far from that。 According to Simon Ford； the fire…damp escaped incessantly； and from that fact the existence of an important vein might be considered certain。 Consequently； the riches of the Dochart pit were not entirely exhausted。 The chief question now was； whether this was merely a vein which would yield paratively little； or a bed occupying a large extent。
Harry； who preceded his father and the engineer； stopped。
〃Here we are！〃 exclaimed the old miner。 〃At last； thank Heaven！ you are here； Mr。 Starr； and we shall soon know。〃 The old overman's voice trembled slightly。
〃Be calm； my man！〃 said the engineer。 〃I am as excited as you are； but we must not lose time。〃
The gallery at this end of the pit widened into a sort of dark cave。 No shaft had been pierced in this part； and the gallery； bored into the bowels of the earth； had no direct munication with the surface of the earth。
James Starr； with intense interest； examined the place in which they were standing。 On the walls of the cavern the marks of the pick could still be seen； and even holes in which the rock had been blasted； near the termination of the working。 The schist was excessively hard； and it had not been necessary to bank up the end of the tunnel where the works had e to an end。 There the vein had failed； between the schist and the tertiary sandstone。 From this very place had been extracted the last piece of coal from the Dochart pit。
〃We must attack the dyke；〃 said Ford； raising his pick； 〃for at the other side of the break； at more or less depth； we shall assuredly find the vein； the existence of which I assert。〃
〃And was it on the surface of these rocks that you found out the fire…damp？〃 asked James Starr。
〃Just there； sir；〃 returned Ford； 〃and I was able to light it only by bringing my lamp near to the cracks in the rock。 Harry has done it as well as I。〃
〃At what height？〃 asked Starr。
〃Ten feet from the ground；〃 replied Harry。
James Starr had seated himself on a rock。 After critically inhaling the air of the cavern； he gazed at the two miners； almost as if doubting their words； decided as they were。 In fact； carburetted hydrogen is not pletely scentless； and the engineer； whose sense of smell was very keen； was astonished that it had not revealed the presence of the explosive gas。 At any rate； if the gas had mingled at all with the surrounding air； it could only be in a very small stream。 There was no danger of an explosion； and they might without fear open the safety lamp to try the experiment； just as the old miner had done before。
What troubled James Starr was； not lest too much gas
mingled with the air； but lest there should be little or none。
〃Could they have been mistaken？〃 he murmured。 〃No： these men know what they are about。 And yet……〃
He waited； not without some anxiety； until Simon Ford's phenomenon should have taken place。 But just then it seemed that Harry； like himself； had remarked the absence of the characteristic odor of fire…damp； for he exclaimed in an altered voice； 〃Father； I should say the gas was no longer escaping through the cracks！〃
〃No longer！〃 cried the old miner……and； pressing his lips tight together； he snuffed the air several times。
Then； all at once； with a sudden movement； 〃Hand me your lamp； Harry；〃 he said。
Ford took the lamp with a trembling hand。 He drew off the wire gauze case which surrounded the wick； and the flame burned in the open air。
As they had expected； there was no explosion； but； what was more serious； there was not even the slight crackling which indicates the presence of a small quantity of firedamp。 Simon took the stick which Harry was holding； fixed his lamp to the end of it； and raised it high above his head； up to where the gas； by reason of its buoyancy； would naturally accumulate。 The flame of the lamp； burning straight and clear； revealed no trace of the carburetted hydrogen。
〃Close to the wall；〃 said the engineer。
〃Yes；〃 responded Ford； carrying the lamp to that part of the wall at which he and his son had； the evening before； proved the escape of gas。
The old miner's arm trembled whilst he tried to hoist the lamp up。 〃Take my place； Harry；〃 said he。
Harry took the stick； and successively presented the lamp to the different fissures in the rock； but he shook his head； for of that slight crackling peculiar to escaping fire…damp he heard nothing。 There was no flame。 Evidently not a particle of gas was escaping through the rock。
〃Nothing！〃 cried Ford； clenching his fist with a gesture rather of anger than disappointment。
A cry escaped Harry。
〃What's the matter？〃 asked Starr quickly。
〃Someone has stopped up the cracks in the schist！〃
〃Is that true？〃 exclaimed the old miner。
〃Look； father！〃 Harry was not mistaken。 The obstruction of the fissures was clearly visible by the light of the lamp。 It had been recently done with lime； leaving on the rock a long whitish mark； badly concealed with coal dust。
〃It's he！〃 exclaimed Harry。 〃It can only be he！〃
〃He？〃 repeated James Starr in amazement。
〃Yes！〃 returned the young man； 〃that mysterious being who haunts our domain； for whom I have watched a hundred times without being able to get at him……the author； we may now be certain； of that letter which was intended to hinder you from ing to see my father； Mr。 Starr； and who finally threw that stone at us in the gallery of the Yarrow shaft！ Ah！ there's no doubt about it； there is a man's hand in all that！〃
Harry spoke with such energy that conviction came instantly and fully to the engineer's mind。 As to the old overman； he was already convinced。 Besides； there they were in the presence of an undeniable fact…… the stopping…up of cracks through which gas had escaped freely the night before。
〃Take your pick； Harry；〃 cried Ford； 〃mount on my shoulders； my lad！ I am still strong enough to bear you！〃 The young man understood in an instant。 His father propped himself up against the rock。 Harry got upon his shoulders； so that with his pick he could reach the line of the fissure。 Then with quick sharp blows h