What circular diagram, introduced by Sir Ebenezer Howard, marketed a spatial reform package linking cities surrounded by a greenbelt?

Answer

Garden City concept

Sir Ebenezer Howard's 1898 publication introduced the Garden City concept, visualized through a circular diagram illustrating linked, smokeless cities surrounded by a greenbelt.

What circular diagram, introduced by Sir Ebenezer Howard, marketed a spatial reform package linking cities surrounded by a greenbelt?
inventiondesigncitytoolurban planning