This is the case in Keelung and Huwei, though mountains aid in the defense. Setting up cannons on them would give us strong positions .... Penghu is not only the gateway to Taiwan but also a key to the north and south seas. To protect Taiwan, protecting Penghu is essential. For protecting the north and south seas, Penghu is also essential as a gateway.
… … 基隆、滬尾兩口雖能停泊兵輪，賴有山險，如有大砲水雷設防，尚能為力，……，澎湖不但為全台之門戶，亦南北洋關鍵，守台灣，須守澎湖；保南北洋，亦必須以澎廈為門戶。