The tricky task of tracking London's swans.

The third week in July calls for London's annual swan census - an appealing spectacle for the newsreel cameras. The six flag-adorned skiffs carry members of two City livery companies, the Vitners and the Dyers, who share ownership of Britain's swan population with the Crown. Every year they 'mark' newly-born cygnets in a ceremony dating back to the 12th century.

A regular calendar custom, the swan upping ceremony was filmed often by early newsreels, which were always on the lookout for pre-planned or predictable events - the quirkier the better. This Gaumont Graphic edition is a bit more matter-of-fact than Topical Budget's 'Swan Upping Starts' (1930), which appeals to a nostalgic sense of 'ancient custom' and British tradition.