The Preparation of Illustrations for Reports of the United States Geological Survey / With Brief Descriptions of Processes of Reproduction

by John L. Ridgway

All periods should be omitted from abbreviations used in the body of a map unless their omission would cause misunderstanding. They are generally unnecessary, and if used on some maps they are likely to be mistaken for symbols representing certain features, such as houses or flowing wells, if either is shown. Periods used on drawings that are to be reproduced "direct" or photomechanically should always be slightly exaggerated.

NAMES OF RAILROADS.

The names of railroads may be written in full or abbreviated, in accordance with the kind of map and the space available. On a sketch map in black and white the initial letters are generally sufficient. On a more detailed map, if there is room enough, the names may be spelled out. As already stated, neither the words "railroad" and "railway" nor the abbreviations R. R. and Ry. should be used on a map.

MAKE-UP OF MAPS.

FORMS FOR CERTAIN FEATURES.

The proper forms for certain features of maps, such as the borders, titles, explanations, bar scales, captions, arrows indicating true north and magnetic declination, source, and authorship, are shown in [Plate VII]. Note particularly the style and position of the marginal matter.

BORDER.

A finished map border is used or omitted according to the kind of map prepared. Diagrammatic maps and maps on which no parallels and meridians appear do not need finished borders. On a map that shows complete areal geologic or other coloring, such as a map in a Survey geologic folio, the border lines tend to destroy the simple effect of the whole map. On a map that is not completely colored and on all very large maps borders are really necessary. If borders are used, however, the space between the neat line and the outer line of the border should be only sufficient to provide proper space for the numbers showing latitude and longitude or township and range. A simple rule[8] for determining the width of this space is as follows: Divide the sum of the dimensions of the map by 2 and find the square root of the quotient, which will represent the width of the border in sixteenths of an inch. Example: Map is 20 by 30 inches; (20 + 30)/2 = 25; square root of 25 = 5; width of border = ⁵/₁₆ inch.

[8] Worked out by Martin Solem, of the U. S. Geological Survey.

The numbers showing latitude and longitude should be in shaded arabic numerals and those showing township and range in gothic. The symbols for degree, minute, and second should not be crowded. On a map that has no added border lines the numbers should be in hair-line gothic.