Walking 600 miles from his Birmingham home, along the wall, and back home again, he wrote in the preface, "I have given a short sketch of my approach to this famous Bulwark; have described it as it appears in the present day, and stated my return.
He walked 600 miles from his Birmingham house to the wall and then back, writing in the preface, "I have outlined my strategy for approaching this famous Bulwark; depicted its current state, and narrated my journey back."