Contrary to previous results with special types, these tests of commercial types represent the capitals as more legible, by about one-fifth, than the lowercase letters; but, in view of the much greater bigness and heaviness of capitals, the earlier judgment would seem to be supported so far as the letter forms of the two classes are concerned.
"The Booklover and His Books"
Harry Lyman Koopman
Considering only the lowercase letters, which represent nine-tenths of the print that meets the eye, we still have four of the most used letters, s e a o, in the lowest fourth of the group, while s in both sizes of type and in all faces stands at the bottom.
"The Booklover and His Books"
Harry Lyman Koopman
The most noticeable feature about it is the absence of the loop to the lowercase 'd,' so conspicuous a feature of the No. 2 type.
"A Short History of English Printing, 1476-1898"
Henry R. Plomer