What's the Name of That Book??? discussion

This topic is about
By the Great Horn Spoon!
SOLVED: Children's/YA
>
SOLVED. YA Historical Fiction - around the year 1900 a young boy of about 12 goes on adventures, ends up on a ship with a pig that can detect thieves, and the final showdown is on a rooftop in his neighborhood. [s]
date
newest »


Praiseworthy didn’t waste a moment. “But one of you, fearing that the sow’s squeal would give you away — one of you approached but didn’t touch a finger to her back. Look around you, gentlemen. If there is a man among you without coal dust on his finger — he has exposed himself as the thief!”
I have heard of this trick before (although I can't remember where), so it's possible it crops up in other books too.
I couldn't find a Google Books preview but there's a copy on archive.org if that helps - https://archive.org/details/bygreatho...
We read this book in my elementary school classes in the late 1990's, so it was likely published between 1980 and 1998 if I had to guess.
The cover was like a halfway cartoon of a sort of skinny, gangly blonde boy with a paperboy cap on.
The plot follows a young man of maybe 12 years old or so. He lives with his parents (if I remember right), and they head out for some kind of vacation or they ship him to a boarding school or something, so he ends up going on some adventures.
There is a part of the plot I remember well, which takes place on a ship. Somebody on the ship has stolen something, and the boy must figure out how to catch the thief. He (and his friend if I remember right) come up with a great plan, which is to gather up the crew of the ship all together in a single room. He holds up a pig to the crew of the ship and says that the pig can detect thieves, if a thief should touch the pig then he will squeal like crazy. So then, they turn the lights off (total darkness) and one by one, he calls each member of the crew to come touch the pig and see if it squeals when the thief touches it. One-by-one, the whole crew touches the pig and it never squeals. At that point, the boy reveals that it's actually just a regular pig, but it has been covered in a fine coal dust, and he asks all the crew members to show their hands, since the thief would not have touched the pig. Sure enough it works and something else happens that I can't remember, but they end up finding who the thief is.
The antagonist of this book is some kind of thief I believe, and they end up facing off on the final scene. The final scene takes place on a rooftop or something like that, where the boy sneaks out there to get away from the thief and they have the final confrontation if I remember right.
Sorry I can't remember more, hope this helps and thank you for your help!