In 1923, a Milwaukee wrecking crew was dismantling an old factory between Water Street and the river, in the heart of downtown. The decayed building had been built in 1877 by Adolph Meinecke to house his "Meinecke Willow Works," which manufactured children's toys and novelties.

As they tore down the last wall, workers came across a mysterious cylinder embedded in the masonry. When the factory had been erected, someone had apparently hidden a large metal canister inside one of its walls. This had been sealed up and forgotten for nearly half a century until the wrecking crew unearthed it.

A group of workers quickly gathered around the strange object. As they cautiously pried off its cover, a long tube of paper burst out like a rocket and scattered the startled onlookers. It had been laid atop a compressed spring, and when the lid was lifted it sprung out like a child's Jack-in-the-Box.

After they recovered themselves, the workers realized that Meinecke had deliberately concealed a kind of time capsule when he constructed the building back in 1877.