Its author, a military man fond of literature, had been governor of Nueva Ecija and, from his experience, wrote a Memoria acerca de la Provincia de Nueva Écija [Report regarding the Province of Nueva Ecija] (Madrid, 1889). The present work results from the knowledge acquired after two years as governor of the district of Davao. It was a previous experience since this book was already edited in 1884, and its publication was delayed for unknown reasons. Most of the book is devoted to narrating the risky reconnaissance expeditions he led. Some sections of the book read like an adventure story told in the first person. It contains abundant information about the geography and inhabitants of the district: description of natives weddings he attended, encounters with local datus, attacks from pagan chiefdoms, etc. The book ends with a curious Spanish-Malayo-Bisaya-Manobo vocabulary. The author reckons there were 66,000 inhabitants in the district, 5,000 of whom were Muslims and only 1,900 Christians. Among the indigenous people, the author distinguishes between those who led a nomadic life and those who lived sedentary lives. It is essential to know the early history of Davao. It is precious work that deserves to be translated into English. Very rare.