§ 4116. Co-operation of Indians shall be sought. In the discharge of the duties imposed by this article, the said commissioner shall endeavor to secure the co-operation of all the several bands of Indians, and for this purpose, shall visit, by himself or his authorized representative, all the reservations where they reside, lay the matter before them in public assembly, inviting them to assist either by appropriating their public moneys to this object, or by setting apart lands and erecting suitable buildings, or by furnishing labor or materials for such buildings, or in any other way which he or they may suggest as most effectual for the promotion of this object.