Sentence:  If his "Title" be ſhort, he "Sets" it in the middle of the "Line", by "Setting <WSD>Quadrats</WSD>" on both ſides: If his "Title" be long, he "Sets" the middle "Line" in the middle: If it make three or more "Lines", he "Indents" the firſt with an m <WSD>"Quadrat</WSD>", and the other with two m <WSD>"Quadrats</WSD>". 
Meaning of the word marked with <WSD> tags:  A quad; a blank metal block used to fill space in lines of type.