that the relative positions of the various details in the three colors are exactly as on the manuscript. Discrepancies are noted, and when satisfactory adjustment has been made the sheet is approved for printing.

Section of Illustrations.

Clear presentation of the subjects with which most scientific papers deal demands the use of illustrations, and many appear in the reports of the Survey. These illustrations are not selected for their pictorial value, but because they assist the reader to understand the text and the subject treated. In works on paleontology, for example, the need of illustrations is so great that it is necessary to figure each type, and often each species, in order to adequately describe its characteristics. For similar reasons the geologist illustrates his paper with structure sections, maps, and landscapes, in order that the reader may see, almost as well as if he were on the spot, the phenomena under consideration.

Prior to the beginning of the fiscal year 1884–85 no corps of artists or draftsmen was permanently employed in the Survey. The illustrations were prepared, suitable processes of reproduction were selected, and proofs were examined by one of the geologists (who was also an artist of exceptional ability), either personally or under his direct supervision, or by contract with persons specially qualified. In a few instances the geologists and paleontologists made their own drawings.

In a report to the Director dated July 13, 1885, the geologist in charge of illustrations stated: "During past years it has been the practice of the Survey to give out a large portion of the work of preparing illustrations to competent draftsmen not connected with the office. This method seemed to be open to objection, and, acting in accordance with instructions from you, I have, within the fiscal year, selected a number of draftsmen having especial qualifications for the work who have been regularly attached to the Survey. The results appear to be entirely satisfactory." This report led to the organization in 1885 of the section of illustrations.

At this time there were four draftsmen, including the chief, regularly employed. Other draftsmen were temporarily engaged under the direction of the persons for whom the drawings were made. The number of draftsmen now regularly employed is ten, including the chief. When there is exceptional demand, work is occasionally given out to draftsmen not connected with the Survey.

The section of illustrations and the section of texts necessarily cooperate during the preparation of the manuscript and the illustrations for a paper, in order to adjust the two parts. The originals from which illustrations are to be prepared generally consist of material of one or more of the following classes: Diagrammatic drawings (sections,

etc.), geologic and other maps, photographic prints, geologic and paleontologic specimens, thin sections, and references or citations. The material belonging to the first and second classes is generally crude, and is used merely as a guide in preparing more elaborate and finished drawings. Each illustration is prepared with the twofold purpose of expressing the fact intended by the author and securing the best possible result in its reproduction by one of the numerous processes in use. This section decides upon the most suitable process of reproduction, writes specifications for the reproduction of each class, examines critically all proofs, keeps complete records and files, and gives attention to all other matters that pertain to the illustration of the various reports of the Survey.

In the early days of the section, as at the present time, drawings were prepared in accordance with the demands of the various reproductive processes in vogue. Photography had not reached its present perfection, and up to the year 1884 the majority of such illustrations were engraved on wood. On referring to any of the reports published prior to that date one will observe a marked deficiency in the scientific value of the illustrations engraved by that process, as compared with more recent reproductions of similar subjects—a lack of value due to the fact that hand work entered too largely into the former. Moreover, the woodcut process was relatively expensive. The 76 woodcuts used in the Seventh Annual Report of the Survey cost $4,825, whereas similar illustrations reproduced by the half-tone process would probably cost less than $600. But as artistic illustrations in the broader sense, many of the woodcuts in the earlier reports stand as examples of exceptional merit in selection and execution.

The half-tone process began to be used for the reproduction of photographs and drawings in 1884. This process has gradually worked into favor, and has revolutionized the illustration of all kinds of literature. Its use has also effected many changes in methods of preparation, and at the present time photographs are used (whenever suitable prints can be obtained) in preference to drawings. It is also used in numerous ways when drawings must be made, and is not only a timesaver, but adds to the element of accuracy in the finished drawing. In other words, new conditions have so modified methods of preparation of illustrations that complete new drawings of certain classes of subjects rarely become necessary. There is still, however, abundant need for skill in the artistic treatment of illustrations, whether in preparing new designs or in "building up" or retouching photographic prints.

During the calendar year 1903 illustrations were prepared and transmitted for the following publications: Three annual reports, 2 monographs, 9 bulletins, 10 water-supply papers, 12 professional papers, and 2 volumes on mineral resources; in all, 1,168 illustrations, many

of which represented groups of separate drawings. In addition to these, hundreds of drawings were prepared within the year which still await transmittal to the engravers.

The processes at present used for the reproduction of illustrations for Survey reports are chromolithography, photolithography, photogelatin, half-tone, zinc etching, wax engraving, and the three-color process. In the preparation of illustrations both economy in preparation and economy in reproduction must be considered. Some processes call for carefully prepared drawings, while others require only the crudest kind of copy. The total cost to the Government is approximately the same whether the drawing is elaborated and refined in the office or the elaboration is left to the reproducer. In deciding the question in any given case the points considered are urgency in getting out the report, quality of result desired, and character of subject.

An important feature in connection with illustrations is that of censorship. An author, thoroughly imbued with his subject, is apt to submit originals, especially photographs, in excess of the needs of his paper. In order to correct this tendency, a committee composed of officers of the Survey, and of which the chief of the section of illustrations is chairman, examines the original material submitted by authors, with a view to the elimination of all superfluous or irrelevant matter.

Section of Photography.

Photography has always been an important adjunct in the work of the United States Geological Survey, and its scope and usefulness have constantly increased. Before dry plates and paper films came into use the work in photography was largely that of recording exploratory and scenic views. The wet-plate process required such bulky apparatus, so much time and labor, and such skill in manipulation of camera and chemicals that its use was practically confined to large parties and to comparatively accessible localities. However, in spite of these disadvantages, a large amount of valuable work, both in field and in office, was done. Indeed, it is not too much to say that many of these early negatives are unsurpassed in scenic value.

With the advent of dry plates and small cameras the use of photography in the field work of both geologist and topographer rapidly increased. Instead of the one photographer with his glass plates and his array of bottles and pans and cumbrous developing tent or boxbarely tolerated in a geologic party and abominated in a topographic party- almost every party chief now has his dry-plate or film camera, and is encouraged to photograph every subject germane to his work, thus adding immensely to the volume, accuracy, and value of his field observations.

As great improvement has been made in office or laboratory methods as in field. This is especially the case in the development of negatives,

by which an almost hopeless field exposure can be made to give creditable results, a dim pencil sketch be reproduced on any desired scale, or a fossil brought out so as to eliminate all effects of color and show only its form and markings.

The photographic laboratory of the Geological Survey is equipped with the most modern appliances. Daylight exposures are no longer made, so that the work of copying maps progresses regardless of sunshine. Two large cameras are used in this work. The maps to be copied are stretched on adjustable frames attached to the walls, each illuminated by two powerful arc lamps which are operated by the photographer from his position at the camera. The camera rolls on tracks and may be elevated or depressed or moved forward or backward for focusing or for procuring reductions to fixed scale, all from one position behind the instrument. In like manner, printing is no longer dependent upon sunlight, but the negative to be printed is held under pressure in a quick-acting frame on trucks, on which it is tilted so as to expose it to an electric light for a few seconds, after which the frame falls back into position and flies open, when the print is removed and a new sensitized sheet is inserted. This process is so rapid that as many as 150 prints from a negative have been made in an hour.

In the Geological Survey photography readily groups itself into field work and laboratory work. It is all under control of a chief photographer, whose powers differ in each branch of the work. To the person using a camera in the field he gives instruction and advice, sees that the instruments purchased are such as are best adapted to the desired work, and that they are kept in repair and issued on proper requisitions. Here his functions cease. He can neither select the views, place the camera, nor time the exposure. He must accept the results brought to him by the field force of the Survey, upon whom the only restriction placed is that the subjects photographed shall be germane to the work in hand. Generally the exposed negatives are sent to the Survey laboratory for developing, but frequently the user of a camera develops his negatives in the field, or has them developed by a local photographer, in order that the results may be immediately known. It often happens that such work is poor, judged by the standard established in the laboratory, but probably the advantage of immediately knowing whether a negative of sufficient value to be used. has been procured more than compensates for the inferior quality.

A record of all exposures made in the field is kept according to forms arranged for the purpose. These forms give a brief description of the locality and subject, condition of light, length of exposure, aperture of lens, and the field number of the negative, and must accompany all plates or films sent to the laboratory from parties in the field or turned in on their return. They furnish the data from

which is made a permanent office record of all negatives that are of sufficient value to be preserved.

All work in the laboratory is done in pursuance of card requisitions made by the division or section chief, countersigned by the chief clerk. This requisition specifies the character and amount of work to be done and the use for which the thing required is intended, and must be accompanied by the subject to be photographed. Upon its receipt by the photographic. section the card is given a serial number and filed, and the requisition is then referred to the proper subsection, to await its turn. When the work is completed the card is returned to the person making the requisition, accompanied by the thing required, who inspects it and receipts for it on the card, which is then filed for a permanent record.

The work done in the laboratory falls into four general classes-map, dry plate, specimen work, and printing and to each of these classes experts are assigned.

If the requisition calls for the reproduction, on either the same, an enlarged, or a reduced scale, of a field map, a county or State map, or some rare chart of early explorations, it is assigned to the map section. Here cameras accommodating plates up to 34 by 34 inches in size are used, and the negatives are made by the wet process. These cameras are mounted on tracks and are worked by slow movement, so that prints of the exact size required can be obtained. In this section two men are constantly employed in making negatives and one in washing and preparing glass. If the requisition calls for the developing of plates or films, it goes to the dry-plate section, where two men are engaged in this work. If a fossil or mineral is to be photographed, it is referred to the specimen section, where photo-micrographic and other special apparatus is used. After negatives are made or developed they are turned over to the printing section, where the specified number of prints are made upon the paper desired. If a negative is of sufficient importance to be preserved, a permanent number is given it and it is filed for future use. Prints from such negatives are preserved for ready inspection in indexed albums, and more copies are made as desired.

The photographic section has now on file about 25,000 negatives and nearly 4,000 lantern slides. A considerable number of the negatives were made by the Powell and Hayden surveys, and constitute an invaluable record of early explorations. The remainder were made by the Geological Survey, by far the larger part since the introduction of the dry-plate process. At the organization of the Geological Survey one photographer and one assistant were employed, and these were engaged almost exclusively in field work. In 1903 the force consisted of a section chief and 8 assistants, employed almost exclusively in the laboratory, while about 75 cameras were used in the field. To obtain a just