Yesterday, in the afternoon, I went for a long walk, beginning in Midtown, where I got off the train at Lexington Avenue and wandered up toward the park, which I entered at the Metropolitan Museum of Art and which I exited an hour or so later on a roadway on the west side of the park, at 85th Street, having circled the reservoir on that broad gravelly section of the Bridle Path that joggers and dog walkers like to use.