The comments of Robert Lincoln O’Brien, writing in the 
Atlantic Monthly  in 1904, indicate a rich field of social material 
that still remains unexplored. For example:

          The invention of the typewriter has given a 
     tremendous impetus to the dictating habit. . . . This 
     means not only greater diffuseness . . . but it also brings 
     forward the point of view of the one who speaks. There is 
     the disposition on the part of the talker to explain, as if 
     watching the facial expression of his hearers to see how 
     far they are following. This attitude is not lost when his 
     audience is following. It is no uncommon thing in the 
     typewriting booths at the Capitol in Washington to see 
     Congressmen in dictating letters use the most vigorous 
     gestures as if the oratorical methods of persuasion could 
     be transmitted to the printed page.