I've got that book, and another titled "Krakatau 1883", by Simkin and Fiske (published in 1983 - the 100-year anniversary of the event).

The though the newer book has some updated science in it, it can't compare to the earlier one in fascinating detail, personal accounts, ship's logs, etc. etc. If you've found the subject interesting, I really recommend Krakatau 1883.

Mike Williams