But, for all that, there come blessed unutterable moments, when the mood and the scene and the companion are all attuned in a soft harmony. Such moments come back to me as I write. I see the mouldering brickwork of a crumbling tomb all overgrown with grasses and snapdragons, far out in the Campagna; or feel the plunge of the boat through the reed-beds of the Anapo, as we slid into the silent pool of blue water in the heart of the marsh, where the sand danced at the bottom, and the springs bubbled up, while a great bittern flew booming away from a reedy pool hard by. Such things are worth paying a heavy price for, because they bring a sort of aerial distance into the mind, they touch the spirit with a hope that the desire for beauty and perfection is not, after all, wholly unrealisable, but that there is a sort of treasure to be found even upon earth, if one diligently goes in search of it. Of one thing, however, I am quite certain, and that is that travel should not be a feverish garnering of impressions, but a delicious and leisurely plunge into a different atmosphere. It is better to visit few places, and to become at home in each, than to race from place to place, guide-book in hand. A beautiful scene does not yield up its secrets to the eye of the collector. What one wants is not definite impressions but indefinite influences. It is of little use to enter a church, unless one tries to worship there, because the essence of the place is worship, and only through worship can the secret of the shrine be apprehended. It is of little use to survey a landscape, unless one has an overpowering desire to spend the remainder of one's days there; because it is the life of the place, and not the sight of it, in which one desires to have a part. Above all, one must not let one's memories sleep as in a dusty lumber-room of the mind. In a quiet firelit hour one must draw near, and scrutinise them afresh, and ask oneself what remains. As I write, I open the door of my treasury and look round. What comes up before me? I see an opalescent sky, and the great soft blue rollers of a sapphire sea. I am journeying, it seems, in no mortal boat, though it was a commonplace vessel enough at the time, twenty years ago, and singularly destitute of bodily provision. What is that over the sea's rim, where the tremulous, shifting, blue line of billows shimmers and fluctuates? A long, low promontory, and in the centre, over white clustered houses and masts of shipping, rises a white dome like the shrine of some celestial city. That is Cadiz for me. I dare say the picture is all wrong, and I shall be told that Cadiz has a tower and is full of factory chimneys; but for me the dome, ghostly white, rises as though moulded out of a single pearl, upon the shifting edges of the haze. Whatever I have seen in my life, that at least is immortal.