“Yegg” was an old slang term for BURGLAR.
While I don’t see in the drawings the item you have, it is clearly described as a vessel of frangible material to hold a toxic liquid, which is to be released upon the use of explosives upon a safe’s door or lock.
US Patent numbers: 1408494 / 1408495
What makes me very certain that this is what it is, is the presumed inventor by the name of Walter C. Beckwith.
This guy has TONS of patents credited to his name, everything from Railroad signaling devices to chemical agent to boobytrap parts and trips. An interesting point, is that MOST of his inventions seem to share a common thread: They either combust, ignite, emit, or injure someone. While Mr. Beckwith was simply inventing things to solve problems encountered in his day, he would CERTAINLY be labeled a TERRORIST if inventing a small fraction of what he came-up with in the modern era of today!
Hope this helps some,
–Vince O–O
PS: If I’m not mistaken, didn’t that blue glass thing come from a glass museum that recently went belly-up? Or are there many of these things floating around out there?
