Sentence:  Thus, when he drew up instructions in lawyer language ... his clerks ... understood him very well. If he had written a love letter, or a farce, or a "ballade", or a story, no one, either clerks, or friends, or <WSD>compositors</WSD>, would have understood anything but a word here and a word there. 
Meaning of the word marked with <WSD> tags:  A person who sets type; a typesetter.