The tower stood here from 1695 until it was demolished in 1934, but the legend outlived the building. It housed the School of Mathematics and Navigation, run by Jacob Bruce — Peter the Great's companion, astronomer and engineer, whom rumour turned into a sorcerer. He was said to keep an observatory at the top, to conduct experiments at night, and to have walled a "black book" into the masonry, one that granted power over everything. The book was looked for during the demolition and never found. Bruce's ghost is said to appear on Sukharevskaya Square since, waiting for the tower to be rebuilt.