History Mystery

This week, we're happy to share more of what the Pine Knot News has learned about the 5,000-pound millstone pulled by the city of Cloquet from resident Bill Stolberg's yard.

The millstone was used at the paper mill in pulp manufacturing. It would be "mounted on a geared pedestal ... and the pulp fiber would be crushed between the rotating millstone and a stationary stone," said an email from Sappi's Tom Radovich, managing director of the mill in Cloquet.

The fiber was pinched and elongated between the rotating millstone and stationary stone, a process that improved the strength properties of the fiber, said Radovich in his email.

"Our modern refiners still follow the same basic principle of fiber development," he wrote.

Nowadays, a high-speed rotor disc rotates between two stationary discs to develop the fiber, he explained.

The millstone from Stolberg's yard, now on display in Cloquet's Spafford Park, would have been used for high-yield pulping in the early 20th century.

City staff poured concrete to set the millstone in the park, where it will function as both a seat and discussion piece. - Pine Knot News