IT was agreed that the inhabitants of the cottage must keep more on their guard than ever. The threats of old Silfax were too serious to be disregarded. It was only too possible that he possessed some terrible means by which the whole of Aberfoyle might be annihilated.

Armed sentinels were posted at the various entrances to the mine, with orders to keep strict watch day and night. Any stranger entering the mine was brought before James Starr, that he might give an account of himself. There being no fear of treason among the inhabitants of Coal Town, the threatened danger to the subterranean colony was made known to them. Nell was informed of all the precautions taken, and became more tranquil, although she was not free from uneasiness. Harry's determination to follow her wherever she went compelled her to promise not to escape from her friends.

During the week preceding the wedding, no accident whatever occurred in Aberfoyle. The system of watching was carefully maintained, but the miners began to recover from the panic, which had seriously interrupted the work of excavation. James Starr continued to look out for Silfax. The old man having vindictively declared that Nell should never marry Simon's son, it was natural to suppose that he would not hesitate to commit any violent deed which would hinder their union.

The examination of the mine was carried on minutely. Every passage and gallery was searched, up to those higher ranges which opened out among the ruins of Dundonald Castle. It was rightly supposed that through this old building Silfax passed out to obtain what was needful for the support of his miserable existence (which he must have done, either by purchasing or thieving).

As to the "fire-maidens," James Starr began to think that appearance must have been produced by some jet of fire-damp gas which, issuing from that part of the pit, could be lighted by Silfax. He was not far wrong; but all search for proof of this was fruitless, and the continued strain of anxiety in this perpetual effort to detect a malignant and invisible being rendered the engineer--outwardly calm--an unhappy man.

As the wedding-day approached, his dread of some catastrophe increased, and he could not but speak of it to the old overman, whose uneasiness soon more than equaled his own. At length the day came. Silfax had given no token of existence.

By daybreak the entire population of Coal Town was astir. Work was suspended; overseers and workmen alike desired to do honor to Simon Ford and his son. They all felt they owed a large debt of gratitude to these bold and persevering men, by whose means the mine had been restored to its former prosperity. The ceremony was to take place at eleven o'clock, in St. Giles's chapel, which stood on the shores of Loch Malcolm.

At the appointed time, Harry left the cottage, supporting his mother on his arm, while Simon led the bride. Following them came Starr, the engineer, composed in manner, but in reality nerved to expect the worst, and Jack Ryan, stepping superb in full Highland piper's costume. Then came the other mining engineers, the principal people of Coal Town, the friends and comrades of the old overman--every member of this great family of miners forming the population of New Aberfoyle.

In the outer world, the day was one of the hottest of the month of August, peculiarly oppressive in northern countries. The sultry air penetrated the depths of the coal mine, and elevated the temperature. The air which entered through the ventilating shafts, and the great tunnel of Loch Malcolm, was charged with electricity, and the barometer, it was afterwards remarked, had fallen in a remarkable manner. There was, indeed, every indication that a storm might burst forth beneath the rocky vault which formed the roof of the enormous crypt of the very mine itself.

But the inhabitants were not at that moment troubling themselves about the chances of atmospheric disturbance above ground. Everybody, as a matter of course, had put on his best clothes for the occasion. Madge was dressed in the fashion of days gone by, wearing the "toy" and the "rokelay," or Tartan plaid, of matrons of the olden time, old Simon wore a coat of which Bailie Nicol Jarvie himself would have approved.

Nell had resolved to show nothing of her mental agitation; she forbade her heart to beat, or her inward terrors to betray themselves, and the brave girl appeared before all with a calm and collected aspect. She had declined every ornament of dress, and the very simplicity of her attire added to the charming elegance of her appearance. Her hair was bound with the "snood," the usual head-dress of Scottish maidens.

All proceeded towards St. Giles's chapel, which had been handsomely decorated for the occasion.

The electric discs of light which illuminated Coal Town blazed like so many suns. A luminous atmosphere pervaded New Aberfoyle. In the chapel, electric lamps shed a glow over the stained-glass windows, whic............