of slender elliptical outline, one side depicting a two-storied pavilion displaying archaic bronzes within, beneath two towering pines and distant mountains, the reverse with scholarly accoutrements and a three-character gilt inscription, Yuegulou, one side incised with a single-line four-character mark 

Yuegulou (Hall for Reading the Ancient Classics) in Beihai park was commissioned by the Qianlong emperor in order to house and create rubbings to record the most famous examples of early calligraphy. This 32 volume collection became known as the Sanxitang Fa Tie ('Rubbings from The Hall of Three Rarities'), which included more than 340 works of 135 major calligraphers from the 4th to the 14th century. The collection was called Sanxitang because it included three rare pieces by calligraphers Wang Xizhi, Wang Xianzhi and Wang Xun.