One morning at Princeton, as I was walking over to Dr. Einstein's home to pick him up for an early morning ramble, I passed a curbside pile of brush awaiting the town's disposal truck. The brush consisted largely of curved canes about four feet long, an inch thick at one end and tapering to about a quarter of an inch thick at the other end. I selected one of the canes and found that if I held the thick end in my hand, extended the cane (arched upward) down to the sidewalk in front of me, and walked forward, the tapered end would chatter along the sidewalk. Of course, for it to work, one had to walk it along a hard surface, like a cement sidewalk or a macadam street.

Equipped with my stick, I called at Dr. Einstein's home on Mercer Street. As we set out for our walk, Dr. Einstein was greatly intrigued by the behavior of my walking stick. “I wish I had one of those,” he said. “Here, take mine,” I replied. “Oh, I couldn't take your stick,” he said. “Well,” I then said, “I know where we can get another like it.” “Let's do that,” he replied. So we went to the brush pile and selected another walking stick. With the two sticks preceding us, and Dr. Einstein beaming like a little boy, we continued our early morning ramble.