When did the compilation of Four Essentials begin? What are its characteristics?

Si Chu was compiled by Zhonghua Book Company on 1924 and ended on 193 1. * * Published five episodes with 336 books, 1 1305 volumes. It was printed in the style of Ju Zhen imitating Song Dynasty, first in paperback, and then in hardcover. This book highlights the practicality of reading ancient books and has made great efforts in "preparation". For example, the Classic Department collects notes on the Thirteen Classics in ancient times, notes on the Thirteen Classics in Qing Dynasty, forming a complete system; The history department collects twenty-four histories and their main chronicles; The sub-department collects the masterpieces of Zhou and Qin philosophers and Confucianism, agriculture, Buddhism and Taoism; The collection department pays attention to the collection of literary works such as Selected Works. In reading study, it provides a number of commonly used and necessary classics for ordinary scholars.