SUGGESTIONS TO COLLABORATORS.
The present writer hopes to receive contributions from travelers and observers, not only in North America, but in other parts of the world. Such collaboration will always receive due credit, and when practicable will be reproduced in the language of the collaborator.
The number and the importance of the contributions received upon the collateral branch of sign-language encourages the hope of similar success in this application for assistance in the monograph on pictographs now in preparation.
The main object of the classification both of the text and of the illustrations in the present paper has been to stimulate the research and assist the collaboration invited, so that reference to the various preceding headings is unnecessary. Some practical suggestions may, however, be offered as follows:
As a small drawing of large rock inscriptions may give an exaggerated idea of the degree of finish or fineness of the subject, it is desirable, in every instance, to affix the scale of the drawing, or to give a principal dimension that may serve as a guide. A convenient scale for ordinary petroglyphs is one-sixteenth of full size. The drawing should be sufficiently close and accurate to show the character of the work. It is desirable to note the lithologic character of the rock or bowlder used; whether the drawing has been etched into the face of the rock, or pecked in more deeply with a sharp implement, and the depth of such pecking; whether the design is merely outlined, or the whole body of the figures pecked out, and whether paint has been applied to the pecked surface, or the design executed with paint only. The composition of paint should be ascertained when possible. The amount of weathering or erosion, together with the exposure, or any other feature bearing on the question of antiquity, would prove important. If actual colors are not accessible for representation the ordinary heraldic scheme of colors can be used.
That sketches even by fair artists, are of not high value in accuracy, is shown by the discrepant copies of some of the most carefully-studied pictographs, which discrepancies sometimes leave in uncertainty the points most needed for interpretation. Sketches, or still better, photographs are desirable to present a connected and general view of the characters and the surface upon which they are found. For accuracy of details “squeezes” should be obtained when practicable.
A simple method of obtaining squeezes of petroglyphs, when the lines are sufficiently deep to receive an impression, is to take ordinary manilla paper of loose texture, and to spread the sheet, after being thoroughly wetted, over the surface desired, commencing at the top. The top edge may be temporarily secured by a small streak of starch or flour paste. The paper is then pressed upon the surface of the rock by means of a soft bristle brush, so that its texture is gently forced into every depression. Torn portions of the paper may be supplied by applying small patches of wet paper until every opening is thoroughly covered. A coating of ordinary paste, as above mentioned, is now applied to the entire surface, and a new sheet of paper, similarly softened by water, is laid over this and pressed down with the brush. This process is continued until three or four thicknesses of paper have been used. Upon drying, the entire mold will usually fall off by contraction. The edge at the top, if previously pasted to the rock, should be cut. The entire sheet can then be rolled up, or if inconveniently large can be cut in sections and properly marked for future purposes. This process yields the negative. To obtain the positive the inner coating of the negative may be oiled, and the former process renewed upon the cast.
Pictographs, when of bright colors and upon a light-colored surface, may readily be traced upon tracing linen, such as is employed by topographers. Should the rock be of a dark color, and the characters indistinct, a simple process is to first follow the pictographic characters in outline with colored crayons, red chalk, or dry colors mixed with water and applied with a brush, after which a piece of muslin is placed over the surface and pressed so as to receive sufficient coloring matter to indicate the general form and relative positions of the characters. After these impressions are touched up the true position may be obtained by painting the lines upon the back of the sheet of muslin, or by making a true tracing of the negative.
A mode of securing the outline once adopted was to clear out the channels of the intaglios, then, after painting them heavily, to press a sheet of muslin into the freshly-painted depressions. The objection to this method is the obvious damage inflicted on the inscription. Before such treatment, if the only one practicable, all particulars of the work to be covered by paint should be carefully recorded.
The locality should be reported with detail of State (or Territory), county, township, and distance and direction from the nearest post-office, railway station or country road. In addition the name of any contiguous stream, hill, bluff, or other remarkable natural feature should be given. The name of the owner of the land is of some secondary value, but that indication is liable to frequent changes. The site or station should be particularly described with reference to the surrounding country and to the natural circumstances and geological history of the location.
When numbers and groups of petroglyphs or rock paintings occur, their relation to each other, to the points of the compass, or to topographical features should be noted, if possible, by an accurate survey, otherwise by numeration and sketching.
The following details should be carefully noted: The direction of the face of the rock. The presence of probable trails and gaps which may have been used in shortening distances in travel. Localities of mounds and caves, if any, in the vicinity. Ancient camping grounds, indicated by fragments of pottery, flint chips, etc. Existence of aboriginal relics, particularly flints which may have been used in pecking; these may be found at the base of the rocks upon which petroglyphs occur. The presence of small mortar-holes which may have served in the preparation of colors.
With reference to pictographs on other objects than rock the material upon which they appear and the substances used in their execution should be reported, as indicated in another part of this paper.
With reference to all kinds of pictographs, it should be noted that mere descriptions without reproduction are of little value. Probable age and origin and traditions relating to them should be ascertained. Their interpretation by natives of the locality who themselves make pictographs or who belong to people who have lately made pictographs is most valuable, especially in reference to such designs as do not represent objects of nature, and which may be either conventional or connected with lines of gesture-signs.