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.
From his home in Birmingham, he walked 600 miles to a wall and then back, writing in the preface, "I have outlined my approach to this famous Bulwark; depicted its current condition, and narrated my journey back."