I came to this conclusion while working all alone on my retaining wall. We live on a hill and some years ago my wife, Margaret, decided it would be nice to have a more level backyard. Implementation of this uxorial preference required that I build an 8-foot retaining wall of large stones and railroad ties. Also, the only way to get the 10 truckloads (40 tons) of new soil around the house was by a one-man (me)...