In the spring of 1992, I lectured at the Instituto Superior Tecnico (ISP), in Lisbon, Portugal, invited by my colleague Miguel Coutinho, who teaches hydraulics at that university. One afternoon, I had coffee with Emidio Santos, a former student of mine from my days at Colorado State University in the late seventies. Emidio taught hydrology at the ISP, and passed away in 2010.

At that time, my hydrology textbook, Engineering Hydrology, Principles and Practices, had been published for three about years. Curious about Emidio's opinion of it, and knowing that he would give me a straight and informed answer, I asked:

"Emidio, what do you think about my book?"

To which he responded, after some thought: "It is a fine book, but it is more hydraulics than hydrology."


The river Tagus, at Villa Franca, Portugal.

The river Tagus, at Villa Franca, Portugal.