The 'Chicago House Method'
Founder James Henry Breasted committed the Epigraphic Survey to the preservation of Egypt's cultural heritage by non-destructive means: through documentation so precise it could stand alone as a replacement in the absence of the original monument. Large-format photography (8x10, 5x7, and 4x5 inch negatives) is an essential tool in this process, and one of the first goals of Chicago House was to create a photographic archive of as many of Egypt's accessible standing monuments as possible, photographed inside and out. Breasted understood, however, that photographs alone cannot always capture all the details of the often damaged or modified wall scenes of individual monuments, since the light source that illuminates also casts shadows that obscure details. To supplement and clarify the photographic record, precise line drawings are produced at Chicago House that combine the skills of the photographer, artist, and Egyptologist.
First the wall surface is carefully photographed with a large-format camera whose lens is positioned exactly parallel to the wall to eliminate distortion. From these negatives, which are digitally scanned and duplicated, photographic enlargements up to 20x24 inches are produced, printed on a special matt-surface paper with an emulsion coating that can take pencil and ink lines. An artist takes this enlarged photographic print mounted on a drawing board to the wall itself, and pencils directly onto the photograph all of the carved detail that is visible on the wall surface, adding those details that are not visible or clear on the photograph. Then, in the studio, the penciled lines are carefully inked with a series of weighted line conventions to show the three dimensions of the relief, and damage that interrupts the carved line is rendered with thin, broken lines that imitate the nature of the break. This can now also be accomplished digitally (see below). In the case of hard-copy drawings, when the inking is complete, the entire photograph is immersed in an iodine bath that dissolves away the photographic image, leaving just the ink drawing. The drawing is then blueprinted, the blueprint is cut into sections and each section is mounted on a sheet of stiff white paper. These "collation sheets" are taken back to the wall where the inked details on the blueprint are thoroughly examined by two Egyptologist epigraphers, one after the other. These epigraphers pencil corrections and refinements on the blueprint itself with explanations and instructions to the artist written in the margins. The collation sheets are then returned to the artist, who in turn takes them back to the wall and carefully checks the epigraphers' corrections, one by one. When everyone is in agreement, the corrections are added to the inked drawing back in the studio, the transferred corrections are checked for accuracy by the epigraphers, and the drawing receives a final review by the field director back at the original wall.
Consultations between artist, epigraphers, and field director, the consensus of all skill sets combined, ensures a finished facsimile drawing that is faithful to what is preserved on the wall in every detail. This is the essence of what is generally referred to as the "Chicago House Method." The corrected ink drawings, photographs, scans, text translations, commentary, glossaries, and duplicate negatives are then taken back to Chicago for processing and publication in large folio volumes for distribution worldwide. These publications are available for sale in hard copy and now also for free distribution in electronic format, part of a new program recently inaugurated by the Oriental Institute, and generously funded by OI Visiting Committee Members Lewis and Misty Gruber.
In some instances, it is not possible to photograph the surface that is being recorded, or to observe it directly, since the stone in question is masked by an adjoining architectural feature. For such cases we have developed a special method of recording by indirect observation. Sheets of aluminum foil are inserted into the interstice and used to make rubbings of the carved surface, a labor-intensive process that results in the extraction of enormous amounts of completely hidden carved information. The impressions thus produced on the foil are then slipped beneath sheets of clear diacetate and traced as if they were the original surface of the block. Once a field drawing on diacetate is completed, the artist copies the original tracing onto another piece of diacetate in the studio in order to refine the ink lines of the original. At this stage the drawing, still at one-to-one scale and thus potentially rather unwieldy in size, is submitted to the photographer, who makes digital photographs of the drawings at a high enough resolution to ensure clear reduced printouts. These printouts are used by the epigraphers as collation sheets. In addition to collations of the drawings, the epigraphers also make notes on the content and condition of the reliefs, as well as measured isometric drawings of the blocks on which they occur. After the collation is completed, the epigraphers and the artist examine the block together to consider the suggested corrections and to reach an agreement regarding the changes to be effected on the drawing. In the last step of the field process, the field director makes a final on-site check of the corrected drawing. The diacetate is then scanned, reduced to scale, and overlaid with vellum, on which the lines of the inscription and other features are inked using the normal Chicago House drawing conventions. This method produces the most accurate possible copies of inscribed surfaces that cannot be seen by eye or camera, and would otherwise escape documentation.