The essential principles of lettering have been described in numerous treatises and are well understood by most draftsmen. The correct form of each letter may be learned from such treatises, but spacing and arrangement are best learned by observation and experience. Good lettering will not strongly attract attention, but even slight imperfections of form, spacing, slant, and shading will be quickly detected and criticized. Map letterers should note that the name of a place or the number of a symbol should be put to the right of the symbol if possible and a little above or below it--not to the left and directly on a line with it, as Tucson=o=, 17=o=, Dallas=o=, Carson=o=. Names indicating large areas, if written from west to east, should curve with the parallels, and all names should be so lettered that "if they should fall they would fall on their feet." Every name should be distinctly legible but not so conspicuous as to subordinate the feature it designates. Lines should therefore not be broken in order to make the lettering clear except where there is possible danger that the smaller spaces may be filled up in printing. The lettering on a map should always be so spaced that it will properly fit the area it is intended to designate. In names consisting of two or more words the letters should not be closely spaced if wide spaces are left between the words. In numbers, except those used to indicate elevations on contour Lines or elsewhere, thousands should always be set off by commas. Draftsmen often draw bad forms for commas, quotation marks, apostrophes, and question marks. The following forms are correct: Comma , ; quotation marks "" ; apostrophe ' ; question mark ? . LETTERING BY TYPE.