Gauge the sky, weight the earth - cutting-edge technology of the Edo period.
Surveying the land with the help of an alidade - a sighting device or pointer for determining directions or measuring angles.
You can see the distance measured from the small window in the lid.
From the left: one-to-one → ten → hundred → thousand → one thousand.
1 to one = about 1.82 m.
This exhibition is based on Global Gallery 2F : Progress in Science and Technology
Photo : NAKAJIMA Yusuke