Introduction 3 
archives as he could in libraries in the United States. But, if one’s work in 
the capital or other place where there are different archives leads him to 
several, it is possible by careful planning to piece together a fair day’s work. 
In addition to rather short hours in some of the repositories, one must be 
prepared for many civil holidays and religious dias de fiesta, when the archives 
are closed. | 
CLIMATIC CONDITIONS. 
Many persons assume that Mexico, lying far to the south, is essentially a 
hot country. While this is true in summer of most of the lowland region of 
the periphery of the Republic, it is by no means the case with the great central 
plateau. Indeed this plateau is rapidly becoming a popular retreat from the 
summer heat of the southern part of the United States. The climate of this 
portion of Mexico is essentially equable and moderate. In the months when 
American students are most likely to frequent the archives of Mexico, 
between May and September, the city of Mexico, Querétaro, Guadalajara, 
San Luis Potosi, Zacatecas, Durango, and Saltillo will be found delightfully 
cool. One who intends to work in the archives of these places either summer 
or winter should be provided with warm clothing, since some of the collections 
are housed in chilly, sunless rooms, on the ground floor. For outdoor wear in 
the middle of the day lighter clothing may be desirable. Places at a lower 
altitude are hot in summer, but the buildings usually have thick walls and are 
cool. . 
CLASSIFICATION. 
For present purposes the archives of Mexico may be classified as those 
located at the city of Mexico, and those preserved outside of that city. In 
each class there are governmental, ecclesiastical, and private collections. A 
complete survey of the field would require an examination of all of these 
classes in all localities. The first division of this book will be devoted to the 
principal archives in the city of Mexico. 
