No one can journey a mile or two along the Thames without noticing the swans, which add so much to the beauty of the royal river, as they "float double, swan and shadow," on some quiet pool, or come ruffling up towards some passing skiff, in defence of their young. A sheet of water is hardly complete as a picture without some swans floating upon it. White specks in the distance, forms of exquisite grace and purity of colour in the foreground, they give a harmony to the composition and add to the scene the interest of life. The moorhen and coot are too inconspicuous as they lurk under the reeds, or swim hurriedly across the open water. The swallow and the kingfisher, brilliant though the plumage of the latter, dart too swiftly by to produce any lasting impression on the mind; but the swan sails slowly along, and lingers here and there, in harmony with the traveller, who is seeking only to drink his fill of nature's charms. The abundance of swans on the Thames is due to the fact that they are carefully tended. They are not to be reckoned among _feræ naturæ_; indeed, though other species are chance visitors, the "mute swan" is never, strictly speaking, a wild bird in England; but they are private property, the Dyers' and the Vintners' Companies being among the principal owners. Keepers are appointed to look after them, especially in the building season, when they are in some danger from predaceous animals, and more from predaceous persons. Still, they can take pretty good care of themselves, for the cock bird is very fierce in defence of his nest or young, and can deal formidable blows with his pinions, although, if he has succeeded in breaking a limb, as popular report asserts, the sufferer's bones must have been rather weak. The nests are generally built on the "aits," where the osier beds afford a quiet retreat and a good foundation for the capacious structure. This is constructed roughly of twigs and reeds, and raised some little height above the ground. In former days, when _fay ce que voudras_ was a motto adopted by City Companies more easily than in the present, they used, as sole conservators of the River Thames, to make an excursion annually in their barges, with all due ceremony and festivity, in order to count and mark their swans. This process was called "swan upping," corrupted generally into "swan hopping." The swans were caught and examined, sometimes not without a good deal of trouble, for a strong old cock bird did not submit himself very willingly to the physical suasion of the "swan crook." Cygnets were marked on the bill with the special symbol of the Company to which the parent birds belonged. The Vintners' Company mark was two nicks, whence, by a slight corruption, came the curious inn-sign of the "swan with two necks." "Swan upping" began on the Monday after St. Peter's Day, just at the time when a water excursion would be most pleasant, in the full warmth of summer,