Chapter 9 of Purcell has a big sign at the end of the chapter saying, "The End."
It's not.
What happened was that an Alert Reader caught an error in Chapter 8 which required correction in all later chapters, as well. I uploaded the correction to Chapter 8, but when I thought I was uploading the corrections to chapters 9 - 18, I, instead, uploaded an (obsolete) letter to Lazeez.
Without the attachment which the letter referenced and in a location no letter should be, the message confused Lazeez. His reply confused me, until I figured out what I had done.
He finally repaired the confusion, but it ended with the sign at the end of chapter 9.
I'm going to go back to Lazeez to fix e p. again.