I enjoyed this book. I liked the reference to 'Robinson Crusoe' and others who got stranded with tools etc from ships and that this group had nothing. The technical descriptions were interesting because they were written in 1874(?). And although some of them were way over my head (at which stage I started skimming them) they were still interesting.
Part I was a bit lengthy and I had to force myself to read through but am very glad I persisted. The engineer was a bit of a smartarse with all the answers to all the problems. But you get that.
I figured fairly early who the 'mysterious' help was but was wondering how he would be introduced to the story.
I didn't like the ending as I don't think all (except for poor Jup [that made me unhappy]) could have survived the explosion of the island. The ending appeared to be very fast and rushed.
All in all I liked the book and will go back and re-read some of the others. Fascinating really, how a book that old can still entertain.
Or maybe I re-read the book and try and find all those weird animals and names he used on google. I was quite glad when he called a Koala a koala and didn't mess with the name for kangaroo or used the scientific name. Some of the others have me stumped but it didn't hurt the story that much.