Sun Dial

By :

Class IIIRainbow group

The Target We set…….We were asked to prepare a sun dial

model which would be the best for measuring the accurate time.

We studied the phenomena of sun dial in the 18th century & compared it with the modern clock.

oMade our own predictions, oWrote our own questions, oRanked them by a list of criteriao Compared and contrasted the resultso Selected the best sun dial possible.

Our model of sun dial.

1. The sun dial is prepared on a card sheet or Frisbee of 5cm,7cm,10cm respectively .

2. One pencil or joker is fixed in the center of diameter to form shadows.

3. The ratio of the size of shadows at different timings is compared.

4. Direction is mentioned through arrow key on sun dial sheet.

5. Gnomon is kept in a smooth sundial which is worked by keeping it in east direction in front of sun on a plane surface.

6. sundial contains marked numbers from 1 to 12.7. Sun dial provides consistency in size of shadow

over the week in different timings.

The Best Proposed Sundial

The shape of sundial is round and it is kept on a plane surface.

It is marked with numbers from 1 to 12 just like modern clock.

Directions are mentioned on it. It is kept on East side. The gnomon is of adequate size.

The Best Proposed The Best Proposed

SundialSundial

Conclusion 1. Group A sundial:

Rejected due to small size of Gnomon, small size of shadow, incorrect direction of sundial, indication of incorrect time, short diameter of sun dial ,to predict the incorrect time.

2. Group B sundial:

Rejected due to incorrect direction of sundial, indication of incorrect time, to predict the correct time.

.3. Group C sundial:

ACCEPTED due to normal size of Gnomon ,normal size of shadow, correct direction of sundial, correct indication of time, normal diameter of sun dial ,to predict the correct time.

Works Cited page

Images and information :

Web sites:

http://www.fi.edu/time/Journey/Sundials/interactsd.htm http://www.sundials.co.uk/projects.htm http://www.metoffice.gov.uk/education/primary/teachers/sundial.html http://www.infraroth.de/slinks.html