Use the metric system instead of (or in addition to) the English system.
Illustrations (line drawings, maps, photographs, shaded drawings) can be intermixed throughout the printed text. They must be clearly numbered in sequence, as they are to appear in the text. They will be termed Figures and should be numbered consecutively; if a group of figures is treated as a single figure, however, the individual components should be indicated by lowercase italic letters on the illustration, in the legend, and in text references: "Figure 9b." Type (double spaced) all legends on a page or pages separate from the text and not attached to the artwork.
In the bibliography spell out book, journal, and article titles, using initial caps with all words except minor terms such as "and, of, the." (For capitalization of foreign language titles, follow the national practice of the language.) Underscore (for italics) book and journal titles. Use the parentheses-colon system: 10(2):5-9 for volume, number, and page citations.
Notes and footnotes, accompanying a manuscript, are to be typed consecutively, double-spaced, and on sheets separate from the text. In typing the notes the number should be typed on the line and followed by a period. The footnote number should be typed slightly above the line and should follow any punctuation mark except a dash.
For free copies of his own paper, a Smithsonian author should indicate his requirements on "Form 36" (submitted to the Press with the manuscript). A non-Smithsonian author will receive fifty free copies; order forms for quantities above this amount with instructions for payment will be supplied when page proof is forwarded.
Notes
[1]: An extensive bibliography, essentially as complete at this time as when it was compiled in the early 1950s, is given on pages 1240-1242 of volume 2 of The Papers of Wilbur and Orville Wright, 1953.
[2]: Max P. Baker was a technical adviser to the Wright estate and as such had complete access to all of the material it contained.
[3]: In the 1890s the wealthy inventor Sir Hiram Stevens Maxim conducted an experiment of considerable magnitude with a flying machine that utilized a twin-cylinder compound steam powerplant. It was developed to the flight-test stage.
[4]: Fred C. Kelly, Miracle at Kitty Hawk, 1951.