More information from OP u/Quick_Coffee_1401:
We opened a time capsule buried in the courthouse lawn in spring 2020. It [was] buried in June 1970. The “capsule” was a pine coffin that was sealed in a concrete vault that looked like it had failed almost immediately. There were several coins that made it and a few plastic trinkets that sort of survived, but all papers and documentation was basically just sludge, with the exception of some newspapers triple-wrapped in garbage bags and a few things on top of that pile. This cylinder was at the bottom of the sludgy remains, along with a horseshoe that was identifiable but rusted thin.
You can see by the picture [that it's] about the length of my finger. It’s solid and rather heavy for its size. I can’t tell if that is a label or a piece of something like athletic tape wrapped around it. It isn’t rusted, although there are some rust spots from nearby objects. It has a groove that runs around the top that suggests maybe a clip held it into something, but there was nothing that survived to give a clue as to what that might have been. This object is displayed in a glass case in the library where I am the director and is among the few surviving relics from the capsule.
EDIT 1: The time capsule was buried in East Tennessee.
EDIT 1.5: This is a solid piece of metal. There is NOT a cap. It does NOT open. Not with a hacksaw nor a laser. It would turn to [a] blob if you used a taser.
EDIT 2: It weighs 3.5 ounces/100 grams. It is 3.5 inches long and 7/16 in diameter.
EDIT 2.5: Not a fuse.
EDIT 2.5.5: Not a cigar holder.
EDIT 2.5.6: Here is a link to a picture of it cleaned up and by the horseshoe.
EDIT 3: With apologies to Dr. Seuss:
It does not jiggle
It does not flap.
It does not have a seam or cap.
It's solid as the Rock of Gibraltar.
From this assessment, I do not falter.
SEE THOSE LAST TWO LINES ABOVE? IGNORE THEM PLEASE, WOULD YOU, LOVE? 'CAUSE IT'S A GOOD THING I DIDN'T BET A DOLLAR TURNS OUT THAT THIS THING IS HOLLER (HOLLOW, but I'm in Tennessee, so I'm going with it.)
100 grams is what it weighs.
No rust but has a patina glaze.
I doused it in some WD-40.
Nothing change worthy can I reporty. (Yeah... I know. The rhyme sucks.)
I removed a portion of the tape.
And with a knife the side did scrape.
I tried to stick a magnet to it.
Nothing happened. That didn't do it.
Despite the torture I inflicted,
including the blade with which I nicked it.
It is basically the same as found
That rainy day when we dug up the ground.
There were no documents, no letters, notes
I could not find any quotes
to give me insight to its history.
So far it's still a mystery.
Answered by Redditor u/char-bacca:
It sure looks like a time capsule tube.
From Redditor u/gulmat:
My vote goes to this, and the seam would be under the tape (which they used to try to waterproof it).
From OP u/Quick_Coffee_1401:
No seam under the tape. I just checked.
From Redditor u/principalskinrash:
I can see a seam in the photo of it all cleaned up. It’s faint but definitely there.
Final update from OP u/Quick_Coffee_1401:
Final update: We got it open!
It turns out this does open. It is something funeral home directors put in caskets in case of catastrophe or natural disaster. A waterproof scroll was tucked inside. It read:
Roger Burke, Mary Jean Burke, Sherry Burke, Stephanie Burke, ages left to right 29, 25, 6, 3. Roger's an embalmer and funeral director. Mary Jean a nurse.
Roger is from Cookeville, Tenn. Mary Jean from Nashville, Tenn. Mary Jean is a direct descendant of James Robertson the founder of Nashville, Tenn.
Some famous persons who I have buried while in Nashville, Tenn. Jim Reeves, country music star killed in plane crash.
Cowboy Copas, Hawshak Hawkins, Texas Ruby all music stars killed in plane crash.
Click here to see what is inside.