Is there some kind of software that would allow me to download this online book and/or convert it to pdf?
http://ip194097.ntcu.edu.tw/memory/TGB/thak.asp?id=578
Of course I could save each page separately and then merge them into a pdf, but it would take a lot of time, since the book has 451 pages.
i would suggest a web crawler like wget or Offline Explorer with the right rules, this should be easy
and even a small batch like
wget "http://ip194097.ntcu.edu.tw/memory/TGB/data/Tbook/TBook1/TBook1_%E9%A0%81%E9%9D%A2_001.png"
.....
wget "http://ip194097.ntcu.edu.tw/memory/TGB/data/Tbook/TBook1/TBook1_%E9%A0%81%E9%9D%A2_451.png"
should be easy to make in minutes with a spreadsheet
Have a look at these previous answers as may be useful:
Software that takes a webpage and collates information from its internal links
[recommends a script and some plugins]
Looking for software: create, manage, export manuals
[Sphinx, LogicalDoc, etc]
