ArchAn arch is a vertical curved structure that spans an elevated space and may or may not support the weight above it, or in case of a horizontal arch like an arch dam, the hydrostatic pressure against it. Arches may be synonymous with vaults, but a vault may be distinguished as a continuous arch forming a roof. Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture, and their systematic use started with the ancient Romans, who were the first to apply the technique to a wide range of structures.
Qianlong EmperorThe Qiánlóng Emperor qian2long2 (25 September 1711 - 7 February 1799), also known by his temple name Emperor Gāozōng of Qing, personal name Hongli, was the fifth emperor of the Qing and the fourth Qing emperor to rule over China proper. The fourth son of the Yongzheng Emperor, he reigned officially from 11 October 1735 to 8 February 1796. In 1796, he abdicated in favour of his son, the Jiaqing Emperor, out of filial piety towards his grandfather, the Kangxi Emperor, who ruled for 61 years, so that he not officially usurp him as the longest-reigning emperor.
