At other times it happens that the meanness and trifling nature of a cause not very obvious to observation has occasioned it to be entirely overlooked, even on account of that very meanness, since no one is willing to acknowledge that he has been alarmed by a cause of little consequence, and which he would be ashamed of mentioning. An incident of this sort happened to a gentleman of birth and distinction, who is well known in the political world, and was detected by the precision of his observation. Shortly after he succeeded to his estate and title, there was a rumour among his servants concerning a strange noise heard in the family mansion at night, the cause of which they had found it impossible to trace. The gentleman resolved to watch himself, with a domestic who had grown old in the family, and who had begun to murmur strange things concerning the knocking having followed so close upon the death of his old master. They watched until the noise was heard, which they listened to with that strange uncertainty attending midnight sounds which prevents the hearers from immediately tracing them to the spot where they arise, while the silence of the night generally occasions the imputing to them more than the due importance which they would receive if mingled with the usual noises of daylight. At length the gentleman and his servant traced the sounds which they had repeatedly heard to a small store-room used as a place for keeping provisions of various kinds for the family, of which the old butler had the key. They entered this place, and remained there for some time without hearing the noises which they had traced thither; at length the sound was heard, but much lower than it had formerly seemed to be, while acted upon at a distance by the imagination of the hearers. The cause was immediately discovered. A rat caught in an old-fashioned trap had occasioned this tumult by its efforts to escape, in which it was able to raise the trap-door of its prison to a certain height, but was then obliged to drop it. The noise of the fall, resounding through the house, had occasioned the disturbance which, but for the cool investigation of the proprietor, might easily have established an accredited ghost story. The circumstance was told me by the gentleman to whom it happened. There are other occasions in which the ghost story is rendered credible by some remarkable combination of circumstances very unlikely to have happened, and which no one could have supposed unless some particular fortune occasioned a discovery. An apparition which took place at Plymouth is well known, but it has been differently related; and having some reason to think the following edition correct, it is an incident so much to my purpose that you must pardon its insertion.