In the 19th century the guitar’s body also underwent changes that resulted in increased sonority. It became broader and shallower, with an extremely thin soundboard. Internally, the transverse bars reinforcing the soundboard were replaced by radial bars that fanned out below the sound hole. The neck, formerly set into a wood block, was formed into a brace, or shoe, that projected a short distance inside the body and was glued to the back; this gave extra stability against the pull of the strings.