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

Fullsize image: https://diqn32j8nouaz.cloudfront.net...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