Horizontal sundial

From Object Wiki

Horizontal sundial
Manufacturer	(unknown)
Production years	1782
Production location	France

This instrument, of French make, is dated 1782, and its gnomon is fixed on a small cannon, which may be discharged at noon.

[edit] How it works

A sundial is used to measure time by casting a shadow using a stick called a gnomon onto a dial which is marked with hours. Because the earth moves at the same speed everyday the movement of the shadow will also be fairly predictable. With this instrument, a lens carried on an adjustable arm projected an image of the sun on the touch-hole of the piece.

[edit] Memories

Do you remember stories about sundials? Add your memories.

[edit] In the Science Museum's Records

Inv. No: 1880-52