This pair, with the rich red colouration of Sang de Boeuf (Bull's Blood) effected by use of copper in the glaze, had been employed in decoration since the Sung dynasty.
Originally the vases were employed as oil lamps, and fitted with ormolu bases in the oriental taste and oil reservoirs and burners. Thus, artistic effort, knowledge and tradition was combined with typical Victorian practicality, and with our adapation for electricity, a century and a half later, the decorative lighting function is in use again.