A historian had found other contentions made by the storyteller to be untrue.
Conservation technicians sifting through 140 years' worth of muck accumulated inside the turret of the USS Monitor have periodically teased historian Jeff Johnston with a facetious cry of "Cat bones, we got cat bones!"
But the researcher with the Monitor National Marine Sanctuary has always been doubtful that a 19th-century memoir contending a ship's cat had been stuffed inside one of the ironclad's 11-inch cannons shortly before the vessel sank was true.
Now, after more than two years of carefully reaming out and sifting the contents of the guns, Johnston is convinced that not only didn't the cat go down with the ship, there was probably never such a mascot aboard the most famous Union ship of the Civil War.
The source of the story was a Yankee sailor named Francis R. Butts, who in 1885 wrote an account of his brief service aboard the Monitor. He had joined the crew just before the vessel began its final voyage in November 1862.
In the last minutes before the Monitor capsized and sank on Dec. 31, 1862, Butts contended that he was alone in the turret when he stuffed his boots and overcoat in one of the guns, and shoved a howling black cat into the breech of the other.
"I would almost as soon have touched a ghost, but I caught her, and placing her in another gun, replaced the wad and tampion; but I could still hear that distressing yowl," Butts wrote.
Johnston, who has dedicated much of his career to studying the Monitor and its Confederate ironclad adversary, the CSS Virginia, has caught Butts stretching the truth in other aspects of his recollections.
The seaman's contention that the ship sailed with its cannons loaded seemed unlikely but forced the preservation crew to work carefully in cleaning the silt and debris from the guns just in case they still contained explosives. They didn't.
Now, with about 90 percent of the barrels cleared, David Krop, the assistant conservator for the Mariners' Museum in Newport News, Va., where the turret is housed, said Thursday, "We've excavated and screened enough material to say with certainty that neither cannon is loaded. We have also failed to find any trace of organic material, such as leather, wool or bone.
"Although we are still clearing concretion and sediment from inside both bores that may hide cat bones or organics, I seriously doubt anything will turn up," Krop said.
"The excavations confirmed my suspicion that Francis Butts fabricated the whole story," Johnston said.
After it fought the Virginia to a draw at Hampton Roads in March 1862, the Monitor quickly became one of the most celebrated vessels in naval history.
Its crew posed for photographs on the deck several times, and thousands of visitors went aboard when the Monitor returned to Washington in October 1862.
Yet no mascot appears in any of the pictures, nor do any contemporary accounts by the crew or others talk about a cat. "It would have been the most famous cat in the Union, but no one else ever mentioned it," the historian said.