電報的發明是19世紀通信革命的重要一章。以光電速度進行信息傳播的關鍵是設計出文字與電訊號之間轉化的符號系統。在廣泛使用的莫爾斯碼系統的基礎上,將字母或數字組成的符號對應到短語、句子,編輯成專用的電碼本,可以實現通信設密和節省成本的效果。1871年國際電報線延伸到中國后,為了解決異于字母文字的漢字收發電報的問題,丹麥大北電報公司設計了最早的漢字電碼本。在此基礎上,晚清官商也進行了諸多嘗試。總理衙門制定和頒發《電信新法》電碼本,無形中建立了一套新的政府信息溝通機制。同時,個別部門和官督商辦的機構也編制自己的密碼本,造成清朝電報"密中有密,密外有密"的現象。

The invention of telegraph is an important part of the communicative revolution in the nineteenth century. It is essential to design a coding system to link written languages to electronic signals. In practice,codebooks were designed to symbolize phrases and sentences with letters and numbers,which can be transformed into electronic signals according to the widely used Morse code. In order to use telegraph to communicate in Chinese language after the international telegraph line reached China in 1871,a Danish telegraph company designed the first codebook for Chinese characters. Based on this codebook,Chinese officials and merchants in late Qing also attempted to design new codebooks. Zongli Yamen made and issued the codebook called New Codes of Telegraph( Dianxin xinfa),so as to establish a new mechanism of government communication. Meanwhile,individual government organs and the businesses run by merchants but supervised by officials also designed their own codebooks. Therefore,a large number of telegraph codebooks were used at the same time in late Qing to result in a very complicated situation in decoding telegrams.