This volume emphasizes the fascination which the life and career of Don Carlos de Sigüenza y Góngora (1645-1700), one time incumbent of the chair of Mathematics and Astrology (i.e., Astronomy) in the Royal University of Mexico, has for Dr. Irving A. Leonard. Documents relating to the career of this creole scholar have been the objective of his searches in the Mexican Archives, and have afforded the foundation for several of his publications. This volume is the first to be presented wholly in Spanish by a Mexican publisher.

Don Carlos was born in Mexico City and educated by the Jesuits. For reasons unknown he did not enter the order, but the fact that he became the Chaplain of the Hospital of Amor de Dios, where he permanently resided, indicates he was regarded as of the regular clergy

In 1672 he won the competition for the before-mentioned professorship. His recognized competency in mensuration frequently led the viceroy to require his services about New Spain. These absences caused numerous interruptions in his teaching schedule. As a consequence of these absences he was often reprimanded and even fined by the university authorities. Documents which illustrate various incidents of this nature in his university career are presented in the first section of the book.

In the closing decades of the 17th century the Spanish Hapsburgs were increasingly preoccupied by the threat of French penetration to Gulf waters from Canada. Rumors of La Salle’s activities led to the viceroy’s decision to reconnoiter the situation. An expeditionary fleet under Admiral de Pez was dispatched for this purpose, to which Don Carlos was assigned as cartographer. This voyage provided Don Carlos’ only opportunity to travel outside the limits of New Spain. Pensacola Bay was readily found and its circuit completed without contact with Indians. From his bearings and notes Don Carlos produced a creditable chart. The second section of the volume reproduces several documents relating to the expedition, including the report of Don Carlos. This is the most detailed survey of Florida topography to that time made by the Spanish. This in translation, was included by Leonard (1939) in his The Spanish Approach to Pensacola, 1689-1693 (Vol. IX, Quivira Society, Albuquerque, N. M.).

The brief third section reveals the continued interest of the Spanish authorities in the security of Pensacola Bay, and presents four short documents of 1698 and 1699, of which Don Carlos contributed three. The bay itself was not permanently occupied until 1698.

For several years prior to his death in 1700, Don Carlos suffered excruciatingly from calculi. In his will he requested an autopsy be made so as to reveal to the physicians whether these were biliary or renal. It is obvious Don Carlos’ innate ability was developed exclusively in New Spain. It is also evident credit for its recognition and encouragement must be given to the Jesuits, who must have stimulated his talents.