Poetry in a math text

     In the 1980s, all students at Bloomsburg University were required to take at least one mathematics course and I worked with colleagues to develop a suitable offering -- one that did not require expertise in algebra but which emphasized problem-solving.  Our course became "Mathematical Thinking" -- and I began to develop suitable materials -- eventually writing and publishing Mathematics in Daily Life:  Making Decisions and Solving Problems (McGraw-Hill, 1986).  Each of the twenty-two chapters of this textbook is introduced with a relevant quote.  Chapter 11, "Visualizing the Structure of Information with a Tree Diagram," opens with two lines by one of my favorite poets, Theodore Roethke:

               Once upon a tree              
               I came across a time.