Sundials have been used since ancient times to tell time by the sun's shadow. The earliest sundials date back to 2000 BC in China and Egypt. Romans spread the use of sundials throughout Europe. Sundials work by casting a shadow on a surface marked to indicate hours of the day. The shadow's position tells the time of day based on the sun's changing position in the sky throughout the year.

1. Written by Emma and Elise

2. Collège J.J.Soulier
Written by Estelle & Eloise

3. Antique sundials

4. Gnomon were used in china 2000 bc

5. Sundials are used since the antiquity
The first ones were invented in the 3rd milenium BC
The oldest sundial from Qumram
near the black sea

6. In Egypt the first sundials were T
shaped
Ce sont les Égyptiens qui ont inventé
les cadrans solaires et les Romains le
leur ont subtilisé

7. The oldest sundial was thoutmosis 's portable sundial
The Caire Museum of ancient Egypt:
Pharaoh Thoutmosis III in sfinx

8. Romans invented the ring sundial
Cadran solaire en marbre du 1er ou 2e s ap JC

9. Crusaders came back in europe with sundials in their
luggages

10. A gnomon is a sundial :
we look at the movement of its shadow on a horizontal surface.

11. Summer
Winter
At noon time is correct. The shadow evoluates trough the seasons

12. Noon is the middle of the day,
between sunrise and sunset

13. We split the path of the shadow in 12 parts

14. Created by Charle Bloud mid 17th century

16. Looking at the Sun is the oldest way to measure time.
south
sun
west
east
north

17. The shadow of a stick decreases untill noon.
Gnomon

18. Many sundials are vertical.
Shadow of stick parallel to the earth indicates,

20. This angle is 90°minus the
latitude of your location
(44°)
Stick
Wall
Ground
North South Direction This angle equals the
location latitude (46°)

22. Notre Cadran solaire analemnique