倉頡 (Cāng Jié), the legendary four-eyed inventor of Chinese characters.
There are two different systems for writing Mandarin Chinese characters, including traditional and simplified; in simplified script the name is written 仓颉. Note that there are (at least) two systems of Romanization for Chinese. The spelling "Ts'ang Chieh" (used in this inscription) is the antiquated Wide-Giles system which has since fallen out of use; it's generally considered standard procedure to use Pinyin Romanization.
P.S. The bronze doors were sculpted by Lee Lawrie in 1939.
For more figures from these bronze doors, see the following post.