All too often publishers give their authors the opportunity to save money by making their own index.
The alternative is to pay, per page, for someone to do it for you. Surprisingly, this often comes out better.
In the 1990's it used to be 50 US cents a page. It probably costs more now.
Given that The Knowledge could and should be a reference book, I think it would benefit from having a better index.
Just today, I looked up "ash" to find chemical processes that can use (e.g. wood) ash as a "raw ingredient."
Not in the index.
Has anyone started working on a better index?
With modern computers it wouldn't be too hard to at least make a search tool and put it on this web site.