Sentence:  With respect to "walking", it is the favourite exercise of my life; I sometimes divert myself with objects on the road, which, my being "on a level" with them, offers to observation; and yet, which, had I been <WSD>perked</WSD> up beyond my natural height on the back of a horse, would have been all overlooked. 
Meaning of the word marked with <WSD> tags:  To perch.