“Waltham Lever Escapement. A device for the governing of speed is the one thing on which accurate time measuring depends.” -Hill, 1921
Hill, Henry Chase The Wonder Book of Knowledge (Philadelphia, PA: John C. Winston Company, 1921)
2400×1040, 276.3 KiB
1024×443, 44.9 KiB
640×277, 24.4 KiB
320×138, 9.0 KiB