Spaces

Pieces of metal, less in heighth than letters, cast to the various bodies of types to form the whites or spaces between words and at the ends of lines for justification. They are cast to various thicknesses, and are called by various names. Those which run five to the em are called thin spaces; four to an em, middle spaces; three to an em, thick spaces; two to an em, en quadrats. The hair spaces average eight to the em, but. range between seven and ten, according to the size of the body.—See Justifying, Hair Spaces, Thin Spaces, &c.