Popular Science Appratus Workshops Private Limited

This is simple instrument to check similar sensation at varying lengths.
It is essentially a caliper, the jaws of which has two pointed extensions.
When the caliper is closed and the extended jaws are touched firmly on forearm of a person who has been asked to close eyes,
it gives feeling of a single point touch.
Even when the jaws are slightly opened the feeling remains the same.
Only at a significant distance does the subject realizes the touch as two point.