rief mention is sometimes very important, as it
may be a clue to new data, or may confirm or refute accepted information
and thus lead to further investigation. Some documents, of course, are
much more explicit than others, but this is no reason why the latter
should be neglected. The value of a source may be subject to
investigation from a number of points of view, but it is not always
possible to obtain the requisite information. Thus the biographies of
authors are an important requisite, but how seldom are they obtainable
with the necessary detail!

The sources of the history of the Rio Grande Pueblos, both printed and
in manuscript, are numerous. The manuscript documents are as yet but
imperfectly known. Only that which remained at Santa Fe after the first
period of Anglo-American occupancy--a number of church books and
documents formerly scattered through the parishes of New Mexico, and a
very few documents held in private hands--have been accessible within
the United States. In Mexico the parish and other official documents at
El Paso del Norte (Juarez) up to the beginning of the eighteenth century
have been examined by me to a certain extent, and at the City of Mexico
the Archivo Nacional has yielded a number of important papers, though
the research has been far from exhaustive, owing to the lack of time and
support. Hence much still remains to be done in that field. Some
destruction of papers of an official character appears to have taken
place at Mexico also, yet with the present condition of the archives
there is hope that much that appears to be lost will eventually be
brought to light; in any event we still have recourse to the Spanish
archives, principally at Sevilla. It was the rule during Spanish
colonial domination to have every document of any importance executed in
triplicate, one copy to remain at the seat of local government, another
to be sent to the viceregal archives, and the third to the mother
country. Hence there is always a hope that, if the first two were
destroyed, the third might be preserved. So, for instance, the
collection of royal decrees (_cedulas_) is imperfect at the City of
Mexico. There are lacunae of several decades, and it is perhaps
significant that the same gaps are repeated in the publication of the
"Cedulas" by Aguiar and Montemayor. In regard to ecclesiastical
documents the difficulty is greater still. The archives of the
Franciscan Order, to which the missions on the Rio Gr