During an inspection visit to the Chané river, in Eastern Bolivia, in January of 1990, a colleague who taught at a South American university engaged me in conversation: "Ponce... What are you doing these days?"

I answered that I had recently completed a paper on the Vedernikov number.

Acknowledging his ignorance of the subject, he said, "The... what number?"

I retorted that he should know, since I understood that he taught Open-channel Hydraulics. Noticing that he was still clueless, I added, "Don't you teach with Chow?" ¹

To which he answered, "Yes, of course."

I then said, "Well, it is there... in Chow."

He said, "Where?"

To which I responded, "In Chapter 8."

He then said, "Which one is that?"

And I responded, "The one titled 'Theoretical Concepts...'"

Finding himself totally at a loss, he acknowledged with a grin, "Oh, yeah... that's the one we skip!"

Flood stage on the Chané river, in Santa Cruz department, Eastern Bolivia, January 1990.