The compilation of "Minutes of Reading History Fangyu", a masterpiece that focuses on military geography and combines natural and human geography, is of course inseparable from Gu Zuyu's own efforts.
In order to compile this giant historical and geographical work, he successively consulted twenty-one histories and more than 100 kinds of geographical records, and quoted from a wide range of sources. At the same time, he also paid more attention to on-site inspections. Whenever he went out, he would definitely observe the city outline, and he also paid attention to the mountains, rivers, roads, and passes. We also conducted in-depth investigations, paying attention to the similarities and differences in geographical conditions whether it was business travelers, military expeditioners, or even when talking with guests. However, no matter whether it is on-site inspection or investigation, due to limited conditions, he can only "occasionally experience it". The main work is still limited to the exploration and examination of library materials. Although the textual research in the book is rigorous and the descriptions and arguments are reliable, he always felt that he was not very satisfied with it, especially the lack of perceptual knowledge that could only be obtained from field trips. Of course, due to the limitations of the times and conditions, and the fact that the whole book was written by Gu Zuyu alone, there are inevitably some omissions and fallacies, but these are not its mainstream and do not affect its brilliance in the forest of historical and geographical masterpieces.
Due to its rich content, complete place names, detailed textual research, and strict structure, "Minutes of Reading History Fangyu" has long been better than "Yuanhe Prefectures and Counties Map" written in the Tang Dynasty and "Yuanhe County Map Chronicles" written in the Song Dynasty. "Taiping Huanyu Ji", and surpassed "Huanyu Tongzhi" and "Da Ming Yitong Zhi" written in the Ming Dynasty. If compared with the masterpiece of history and geography of the Qing Dynasty and the official-edited "Unification of the Qing Dynasty", it has its own merits and is not inferior. It has still become an important reference book that historical geographers and even scholars who study history, economy, and military must read.