The seal chop of the present ivory carving was most probably re-carved in the latter half of the 19th century as identified by the four-character seal mark, Weng Tonghe yin. The present carving is a personal seal of the late Qing official Weng Tonghe (1830-1904) who became tutor to Emperor Tongzhi, the son of Empress Cixi, in 1866. After the Emperor's death in 1874, the Empress appointed Weng as tutor to the following successor, Guangxu. Weng later became a close and trusted minister to Emperor Guangxu, and for the next twenty-four years played a key role in China's domestic and foreign affairs.
From the subject-matter, carving style and patination, the seal can be dated to the late Ming/early Qing period. It appears that a number ceramic seals of square form with similarly carved chilong amidst a dense ground of ruyi heads, were used in the Imperial library by Prince Heshuo Yongqin, who later became Emperor Yongzheng. A number of these ceramic seals bearing the Prince's official 'Heshuo Yongqin' title, from the Palace Museum collection, are illustrated in Mingqing Dihou Baoxi, Forbidden City Press, 1994, pps. 190-193. There was a practice amongst scholars and collectors that some seals were incised with a short inscription on their vertical sides, recording a certain carver or a particular event. In some cases, seals of organic material are found with the seal chops re-carved, bearing the owner's name or sobriquet to indicate new ownership, as in the case of the present example.