My memory of fog draws mostly on the years spent in the midwest. That memory is strongest when recalling fog that moved and changed with the same speed as flowers following the path of the sun across the day. That memory coincides with the fog of Carl Sandburg which moves stealthily, gracefully as if on cat feet. When I was 10, the Fourth of July involved a display of fireworks held in the field across the street and the event had two parts: the display in the evening of the 4th, followed the next morning by the search through the field for any of the unspent firework fragments that might rain down on the field. We would collect those fragments and then Conrad's dad would light them in the driveway as we watched and waited for something dramatic. One year on that morning after, a fog thicker than I'd ever seen before covered the field. We could hear the voices of all the other seekers in the field, but we could not see more than 3 feet in any direction. Find one fragment an...