in the glorious light of day？〃
〃No； Harry；〃 replied the girl； 〃I shall like to think about it； but I am glad to go back with you to our dear old home。〃
〃Nell！〃 said Harry； vainly attempting to steady his voice； 〃are you willing to be bound to me by the most sacred tie？ Could you marry me； Nell？〃
〃Yes； Harry； I could； if you are sure that I am able to make you happy；〃 answered the maiden； raising her innocent eyes to his。
Scarcely had she pronounced these words when an unaccountable phenomenon took place。 The Rob Roy； still half a mile from land； experienced a violent shock。 She suddenly grounded。 No efforts of the engine could move her。
The cause of this accident was simply that Loch Katrine was all at once emptied； as though an enormous fissure had opened in its bed。 In a few seconds it had the appearance of a sea beach at low water。 Nearly the whole of its contents had vanished into the bosom of the earth。
〃My friends！〃 exclaimed James Starr； as the cause of this marvel became suddenly clear to him； 〃God help New Aberfoyle！〃
CHAPTER XVI A FINAL THREAT
ON that day； in the colliery of New Aberfoyle； work was going on in the usual regular way。 In the distance could be heard the crash of great charges of dynamite； by which the carboniferous rocks were blasted。 Here masses of coal were loosened by pick…ax and crowbar； there the perforating machines； with their harsh grating； bored through the masses of sandstone and schist。
Hollow； cavernous noises resounded on all sides。 Draughts of air rushed along the ventilating galleries； and the wooden swing…doors slammed beneath their violent gusts。 In the lower tunnels； trains of trucks kept passing along at the rate of fifteen miles an hour； while at their approach electric bells warned the workmen to cower down in the refuge places。 Lifts went incessantly up and down； worked by powerful engines on the surface of the soil。 Coal Town was throughout brilliantly lighted by the electric lamps at full power。
Mining operations were being carried on with the greatest activity； coal was being piled incessantly into the trucks； which went in hundreds to empty themselves into the corves at the bottom of the shaft。 While parties of miners who
had labored during the night were taking needful rest； the others worked without wasting an hour。
Old Simon Ford and Madge； having finished their dinner； were resting at the door of their cottage。 Simon smoked a good pipe of tobacco； and from time to time the old couple spoke of Nell； of their boy； of Mr。 Starr； and wondered how they liked their trip to the surface of the earth。 Where would they be now？ What would they be doing？ How could they stay so long away from the mine without feeling homesick？
Just then a terrific roaring noise was heard。 It was like the sound of a mighty cataract rushing down into the mine。 The old people rose hastily。 They perceived at once that the waters of Loch Malcolm were rising。
A great wave； unfurling like a billow； swept up the bank and broke against the walls of the cottage。 Simon caught his wife in his arms； and carried her to the upper part of their dwelling。
At the same moment； cries arose from all parts of Coal Town； which was threatened by a sudden inundation。 The inhabitants fled for safety to the top of the schist rocks bordering the lake； terror spread in all directions； whole families in frantic haste rushed towards the tunnel in order to reach the upper regions of the pit。
It was feared that the sea had burst into the colliery； for its galleries and passages perated as far as the Caledonian Canal。 In that case the entire excavation； vast as it was； would be pletely flooded。 Not a single inhabitant of New Aberfoyle would escape death。
But when the foremost fugitives reached the entrance to the tunnel； they encountered Simon Ford； who had quitted his cottage。 〃Stop； my friends； stop！〃 shouted the old man； 〃if our town is to be overwhelmed； the floods will rush faster than you can； no one can possibly escape。 But see！ the waters are rising no further！ it appears to me the danger is over。〃
〃And our rades at the far end of the works……what about them？〃 cried some of the miners。
〃There is nothing to fear for them；〃 replied Simon； 〃they are working on a higher level than the bed of the loch。〃
It was soon evident that the old man was in the right。 The sudden influx of water had rushed to the very lowest
bed of the vast mine； and its only ultimate effect was to raise the level of Loch Malcolm a few feet。 Coal Town was uninjured； and it was reasonable to hope that no one had perished in the flood of water which had descended to the depths of the mine never yet perated by the workmen。
Simon and his men could not decide whether this inundation was owing to the overflow of a subterranean sheet of water perating fissures in the solid rock； or to some underground torrent breaking through its worn bed； and precipitating itself to the lowest level of the mine。 But that very same evening they knew what to think about it； for the local papers published an account of the marvelous phenomenon which Loch Katrine had exhibited。
The surprising news was soon after confirmed by the four travelers； who； returning with all possible speed to the cottage； learned with extreme satisfaction that no serious damage was done in New Aberfoyle。
The bed of Loch Katrine had fairly given way。 The waters had suddenly broken through by an enormous fissure into the mine beneath。 Of Sir Walter Scott's favorite loch there was not left enough to wet the pretty foot of the Lady of the Lake； all that remained was a pond of a few acres at the further extremity。
This singular event made a profound sensation in the country。 It was a thing unheard of that a lake should in the space of a few minutes empty itself； and disappear into the bowels of the earth。 There was nothing for it but to erase Loch Katrine from the map of Scotland until （by public subscription） it could be refilled； care being of course taken； in the first place； to stop the rent up tight。 This catastrophe would have been the death of Sir Walter Scott； had he still been in the world。
The accident was explicable when it was ascertained that； between the bed of the lake and the vast cavity beneath； the geological strata had bee reduced to a thin layer； incapable of longer sustaining the weight of water。
Now； although to most people this event seemed plainly due to natural causes； yet to James Starr and his friends； Simon and Harry Ford； the question constantly recurred； was it not rather to be attributed to malevolence？ Uneasy suspicions continually harassed their minds。 Was their evil
genius about to renew his persecution of those who ventured to work this rich mine？
At the cottage； some days later； James Starr thus discussed the matter with the old man and his son： 〃Well； Simon；〃 said he； 〃to my thinking we must class this circumstance with the others for which we still seek elucidation； although it is no doubt possible to explain it by natural causes。〃
〃I am quite of your mind； Mr。 James；〃 replied Simon； 〃but take my advice； and say nothing about it； let us make all researches ourselves。〃
〃Oh； I know the result of such research beforehand！〃 cried the engineer。
〃And what will it be； then？〃
〃We shall find proofs of malevolence； but not the malefactor。〃
〃But he exists！ he is there！ Where can he lie concealed？ Is it possible to conceive that the most depraved human being could； single…handed； carry out an idea so infernal as that of bursting through the bed of a lake？ I believe I shall end by thinking； like Jack Ryan； that the evil demon of the mine revenges himself on us for having invaded his domain。〃
Nell was allowed to hear as little as possible of these discussions。 Indeed； she showed no desire to enter into them； although it was very evident that she shared in the anxieties of her adopted parents。 The melancholy in her countenance bore witness to much mental agitation。
It was at length resolved that James Starr； together with Simon and Harry； should return to the scene of the disaster； and endeavor to satisfy themselves as to the cause of it。 They mentioned their project to no one。 To those unacquainted with the group of facts on which it was based； the opinion of Starr and his friends could not fail to appear wholly inadmissible。
A few days later； the three friends proceeded in a small boat to examine the natural pillars on which had rested the solid earth forming the basin of Loch Katrine。 They discovered that they had been right in suspecting that the massive columns had been undermined by blasting。 The blackened traces of explosion were to be seen； the waters having subsided below the level of these mysterious operations Thus the fall of a portion of the vast vaulted dome was proved to have been premeditated by man； and by man's hand had it been effected。
〃It is impossible to doubt it；〃 said James Starr； 〃and who can say what might not have happened had the sea； instead of a little loch； been let in upon us？〃
〃You may well say that；〃 cried the old overman； with a feeling of pride in his beloved mine； 〃for nothing less than a sea would have drowned our Aberfoyle。 But； once more； what possible interest could any human being have in the destruction of our works？〃
〃It is quite inprehensible；〃 replied James Starr。 〃This case is something perfectly unlike that of a band of mon criminals； who； concealing themselves in dens and caves； go forth to rob and pillage the surrounding country。 The evil deeds of such men would certainly； in the course of three years have betrayed their existence and lurking…places。 Neither can it be； as I sometimes used to think； that smugglers or coiners carried on their illegal practices in some distant and unknown corner of these prodigious caverns； and were consequently anxious to drive us out of them。 But no one coins false money or obtains contraband goods only to conceal them！
〃Yet it is clear that an implacable enemy has sworn the ruin of New Aberfoyle； and that some interest urges him to seek in every possible way to wreak his hatred upon us。 He appears to be too weak to act openly； and lays his schemes in secret； but displays such intelligence as to render him a most formidable foe。
〃My friends； he must understand better than we do the secrets of our domain； since he has all this time eluded our vigilance。 He must be a man experienced in mining； skilled beyond the most skillful…… that's certain； Simon！ We have proof enough of that。
〃Let me see！ Have you never had a personal enemy； to whom your suspicions might point？ Think well！ There is such a thing as hatred which time never softens。 Go back to recollections of your earliest days。 What befalls us appears the work of a stern and patient will； and to explain it demands every effort of thought and memory。〃
Simon did not answer immediately……his mind evidently engaged in a close and candid survey of his past life。 Presently； raising his head； 〃No；〃 said he； 〃no！ Heaven be my witness； neither Madge nor I have ever injured anybody。 We cannot believe that we have a single enemy in the world。〃
〃Ah！ if Nell would only speak！〃 cried the engineer。
〃Mr。 Starr……and you； father；〃