The mention of artillery recalls the fact that His Highness was an amateur of ordnance.  He established a gun-foundry on the island, and what he did not know about the art of casting pieces, as practised in his day, was plainly not worth knowing.  Had it not been for his passionate love of testing new processes and new combinations of metal, he might have attained to a European reputation in that department.  But he was always experimenting, and the consequence was that his cannons were always splitting.  One, however, a monster of its kind, remained intact, to outward appearances.  It was fired on every conceivable occasion—­to summon the Militia, for example, from remote corners of the island at any hour of the day or night, a considerable hardship to those who lived at a distance of two or three miles, seeing that according to the instructions set forth in the Militiaman’s Year-book, the sternest penalties were imposed upon all who failed to appear in their ranks at the Palace gates within five minutes after the signal had been sounded.

It was a perilous gun to handle.  Owing to some undiscoverable flaw of construction or imperfection in the alloy, the monster soon developed a disconcerting knack of back-firing, hazardous to life and limb.  It stands to reason that the Good Duke attached no undue importance to any trifling disaster accruing therefrom.  On the contrary, in order to be sure of a thunderous detonation, he often deigned to superintend in person the loading of this particular piece.

“More powder,” he would then command.  “More powder!  Ram it in!  Never mind her little caprices!  A good salute is worth a good soldier!  More powder!  Fill her up to the brim!  She’s only playful, like her master.”  Those who lost fingers or hands or arms received the Order of the Golden Vine.  Whenever a major portion of the anatomy, a head or so forth, went astray, the victim was posthumously ennobled.

Since his day, thanks to the science of a Paduan engineer, this defect has been almost completely overcome, and the gun can still be heard on great occasions, such as the Duke’s birthday, the Festival of the Patron Saint, or the visit to the island of some foreign sovereign; it is also discharged, as of yore, to summon the Militia for the purpose of quelling any popular disturbance.  But even now it occasionally relapses into its old humours—­with this difference, that instead of being decorated with a coveted distinction, the disabled man is sent to the hospital and told not to make a fool of himself next time.

This was the gun whose sound attracted the strained attention of Mr. Keith and his companions, far away, on the sea, under the cliffs.

CHAPTER XX

The firing had ceased; the boat began to glide forwards once more.  But Mr. Heard’s eye remained fixed upon the ill-omened black rock.  The sun’s rays had already licked dry the moisture on its surface; it shone with a steady dull glow.  Some malefic force seemed to dwell here.  Some demon haunted the place, peering out of the crevices or rising up from the turquoise-tinted water at its foot.  The suicides’ rock!