The expenditures thus far authorized for the preservation of Casa Grande ruin have been made in such manner as to meet the most urgent needs only, and without them the structure would probably have been, before this time, beyond the reach of preservation. The preservative works were undertaken as emergency measures, rather than as steps in carrying out a well-considered plan. From the outset it has been understood by architects and archeologists and others familiar with the structure that preservation can be insured only by throwing a roof over the entire ruin in such manner as to protect the walls from the fierce rainstorms which occasionally occur in the Gila valley. No lesser work will preserve the ruin more than a generation or two; and unless this work of roofing is contemplated and is undertaken within a few years, the emergency work will be of little avail and the money expended therein will be lost. Accordingly, assuming a desire and continued intention on the part of the Government to preserve this noteworthy relic, no hesitation is felt in recommending that a suitable roof be placed over Casa Grande ruin, at such time as may be expedient; and, in view of the rapidity with which destruction is now in progress, there is no hesitation in saying that the work should be undertaken at the earliest practicable date. It should be added that neither the Director nor any of the collaborators in the Bureau of American Ethnology have visited Casa Grande ruin for some three years, and accordingly that there are no data in this office to indicate whether there is especially urgent necessity for undertaking preservative work at this time; but much confidence is placed in the judgment of the custodian, Reverend Isaac T. Whittemore, who is known to several collaborators in the Bureau. The subject of the preservation of Casa Grande, in many respects the most noteworthy ruin in the United States, is deemed important; and if the Secretary of the Interior desires more specific information concerning the present condition of the ruin, as a basis for further action or judgment, it will be a pleasure to have an officer of this Bureau make a special examination of, and report on, the ruin during the autumn. I have the honor to be, yours, with great respect, W J McGee, _Acting Director_. The Secretary of the Interior. IV. _Letter of the Acting Secretary of the Interior to the Director of the Bureau of American Ethnology, approving the suggestion that Casa Grande be visited with a view of determining the desirability of its further protection_ Department of the Interior, _Washington, September 12, 1895_. The Director of the Bureau of American Ethnology, _Smithsonian Institution_.