a large number of observers traveling for a long time over the continent for the same express purpose.  The observations relating to signs were all made here by the same persons, according to a uniform method, in which the gestures were obtained directly from the Indians, and their meaning (often in itself clear from the context of signs before known) was translated sometimes through the medium of English or Spanish, or of a native language known in common by some one or more of the Indians and by some one of the observers.  When an interpreter was employed, he translated the words used by an Indian in his oral paraphrase of the signs, and was not relied upon to explain the signs according to his own ideas.  Such translations and a description of minute and rapidly-executed signs, dictated at the moment of their exhibition, were sometimes taken down by a phonographer, that there might be no lapse of memory in any particular, and in many cases the signs were made in successive motions before the camera, and prints secured as certain evidence of their accuracy.  Not only were more than one hundred Indians thus examined individually, at leisure, but, on occasions, several parties of different tribes, who had never before met each other, and could not communicate by speech, were examined at the same time, both by inquiry of individuals whose answers were consulted upon by all the Indians present, and also by inducing several of the Indians to engage in talk and story-telling in signs between themselves.  Thus it was possible to notice the difference in the signs made for the same objects and the degree of mutual comprehension notwithstanding such differences.  Similar studies were made by taking Indians to the National Deaf Mute College and bringing them in contact with the pupils.

By far the greater part of the actual work of the observation and record of the signs obtained at Washington has been ably performed by Dr. W.J.  HOFFMAN, the assistant of the present writer.  When the latter has made personal observations the former has always been present, taking the necessary notes and sketches and superintending the photographing.  To him, therefore, belongs the credit for all those references in the following “LIST OF AUTHORITIES AND COLLABORATORS,” in which it is stated that the signs were obtained at Washington from Indian delegations.  Dr. HOFFMAN acquired in the West, through his service as acting assistant surgeon, United States Army, at a large reservation, the indispensable advantage of becoming acquainted with the Indian character so as to conduct skillfully such researches as that in question, and in addition has the eye and pencil of an artist, so that he seizes readily, describes with physiological accuracy, and reproduces in action and in permanent illustration all shades of gesture exhibited.  Nearly all of the pictorial illustrations in this paper are from his pencil.  For the remainder, and for general superintendence of the artistic department of the work, thanks are due to Mr. W.H.  HOLMES, whose high reputation needs no indorsement here.