Peruvian balance beam scale from 500 A.D. Made from bone, string, and shells.

Fullsize image: https://s3-us-west-1.amazonaws.com/h...e_fullsize.jpg



Previously:

60,000-lb crane scale - photo
Roberval balance - video
NIST-4 Kibble balance - photo
Definition of kilogram, amp, and kelvin set to change forever
Mushroom packing scale - GIF