longer lines, and finds also that they facilitate a rhythmical regularity of eye-movement, both being conditions which contribute to speed and ease of reading. His tests showed that such lines (a little longer than newspaper lines) were read at greater speed and with shorter pauses than lines of twice the length.
Dearborn argues, and correctly I think, in favor of uniformity in the length of lines, particularly in books for children. The reader drops quickly into a habit of making a regular number of movements and pauses per line, for a given passage, and broken lines confuse and prevent the formation of such habits. However, a slight indentation every other line may, he thinks, be of distinct advantage.
Dearborn thinks that a line of 75-85 millimeters combines a good many advantages, and we are certainly safe in putting 90 millimeters as a maximum, with a preference for lines of 60 to 80 millimeters.
The smaller books which can be easily held in the hand during the reading are to be preferred, and on the whole have grown in popular favor. The larger books usually have to lie on a support, which exposes the letters at an angle, greatly lessening their legibility and producing the equivalent of a material decrease in the size of type. As to the forms of particular letters, many changes are cryingly needed. However, further investigation is needed before we are warranted in requiring changes of the printer. We know that such letters as t, z, o, s, e, c, i, are comparatively illegible. C, e, and o are often confused with each other, and i with 1, h with k, etc. This confusion can be avoided by making certain changes in these letters, and their legibility can be increased. Certain excellent recommendations of changes in particular letters have been made by Javal, Cohn, Sanford, and others.
However, there are many things to be considered in making such changes, and further thorough and mature investigation is needed before any letter is permanently changed. The whole matter should be placed in the hands of a competent specialist or committee of specialists, to be worked over experimentally and advised upon in the light of the psychology of reading, the history of typography, esthetic considerations, the convenience of printing, and the lessons of experience generally. Changes should not be made on the single basis of experiments upon the comparative legibility of isolated letter-forms. A letter whose legibility in isolation is bad may sometimes contribute most to the legibility of the total word-form. Studies now being made of the comparative legibility of letters as seen in context will doubtless throw light on this point. The subject is too complex to permit the adoption of recommendations that are based on study, however careful, of any single aspect, or on anything that does not include a careful study of all the factors. It is high time, however, that there