Marvelous Maps and Measures

Lines on the pillar of Heidelberg's Karl-Theodor Bridge record the dramatic heights of past floods.

These two 15th-century metal rods allowed people to check if they were swindled or not.

A small collection of objects of a bygone era hide in plain view.

Presented to the city in 1910 for public use, these brass markers show varying lengths.

Though they might seem like arbitrary scratches in the wall, these were once official measures of length.

This small bronze pyramid marks the center of Belgrade, but some say it is a Masonic symbol.

This stone in Lake Geneva was once the reference point used to determine altitude in Switzerland.

The memory of the ancient unit of measurement of local builders.

In this scale model, our neighboring planets are represented by metal spheres spread across an English village. The nearest stars are represented by spheres in California and Australia.

This lesser-known geographic marker was the reference point for all surveys of the continent for 75 years.

The first thermometer made with the almost-universal temperature scale is backwards.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

This stone obelisk is a relic of the 17th-century Swedish mile markers.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

An unassuming rod in the Netherlands was once the old standard unit of length for the entire Dutch empire.

The former global standard for the exact mass of one kilogram sits under lock and key outside Paris.

This historic system is the zero level benchmark for measuring the depths and altitudes of the Baltic.