THE SPIRAL WALK: Turns: 7.5 Outer length: 268.5 m Inner length: 85.5 m Outer rise: 10 % Inner rise: 33% Average rise per. turn: 3.74 m HEIGTH: Street to platform: 34.8 m OBSERVATORY: Heigth: 7 m Diameter: 3 m STAIRS: Wood staircase: 28 steps Stone staircase: 31 steps
Center to the outside of the innerwall: 195 cm Center to the inside of the outerwall: 610 cm Radius: 768 cm Some curious informations: Geografical position: 12° 34' 37" 11 east. 55° 40' 55" 06 north. Weight: 5914 t (specific gravity of clay + stone: app. 2 t/m³)
THE LIBRARY HALL Heigth: 3.85 m Area: 811 m2 Volume: 3121.5 m3 Weight of the air in the library: 3.758 t