Spring 2008 Reports and Photos
Vastseliina Boarding School, Estonia Collège Antonin Perbosc, Tarn et Garonne, France
Matthew and Peter Sowerbutts, Adelaide South Australia  
Vastseliina Boarding School, Estonia

Letter of Introduction

Grade Level: 9th Latitude is 57°44'41" N Longitude is 27°15'57" E.

Hallo! We are from Vastseliina Boarding School. Our pupils are very talkative, adventurous and lively. We have difficulties in concentrating and we need all the time new and new activities.
We live in Estonia. Estonia is situated in Northern Europe, on the coast of the Baltic Sea, neighboring Finland, Sweden, Latvia and Russia. It is a country with 1.4 million people. Interesting facts about Estonia:
- Estonia's area of 45 227 km2 is similar to that of the Netherlands, but the population (1.4 million) is ten times smaller.
- The length of the longest day in summer is over 19 hours, while the shortest winter day lasts only six hours. It is not completely dark at night from the beginning of May until the end of July.
- Estonia has more than 1 500 islands, 1 000 lakes (5 per cent of the Estonian territory), 7 000 rivers and streams. Bogs and wooded swamplands of different types cover over one fifth of the country.
- Estonia is a sea country.
- Estonia is very rich in forests - various kinds of forests cover almost half of Estonia's territory. Elk, wild boar, bear and lynx are amongst Estonia's common large mammals. About 10 per cent of Estonia is a nature reserve.
- The average temperature of the coldest month, February, is –3.5° to – 7 °C and may sink to -20°C, that of the warmest, July, being 16° to 20°C and may rise to +30°C.

Final report

Latitude 57° 44' 41'' N Longitude 27° 15' 57'' E

Edgar’s team
Height of the gnomon 100 cm
Lenght of the shadow 149 cm
Angle of the sun 56°7' = 56,133°
First partner located on the equator
Latitude 00° 00' 00''
Angle of the sun 0°
Distance to equator 6416 km
Circumference : 6416 km * 360° / (56.133° - 0°) = 41148 km

Second partner Osnovna škola located in Serbia.
Latitude 43° 37' 41''
Height of the gnomon 100 cm
Lenght of the shadow 87.1 cm
Angle of the sun 41°3' = 41.056°
Distance to Osnovna škola 14.1167° x 111.111 km = 1569 km
Circumference : 1569 km * 360° / (56.133° - 41.056°) = 37416 km

Carmen’s team
Height of the gnomon 100 cm
Lenght of the shadow 153 cm
Angle of the sun 56°49' = 56.832°
First partner located on the equator
Latitude 00° 00' 00''
Angle of the sun 0°
Distance to equator 6416 km
Circumference : 6416 km * 360° / (56.832° - 0°) = 40629 km

Second partner Xiamen International located in China
Latitude 24° 27' 00''
Height of the gnomon 100 cm
Lenght of the shadow 39.75 cm
Angle of the sun 21°40' = 21.678°
Distance to Xiamen International 33.2947° x 111.111 km = 3699 km
Circumference : 3699 km * 360° / (56.832° ° - 21.678°) = 37880 km

Third partner Ecole Lafontaine located in France
Latitude 50° 17' 00''
Height of the gnomon 100 cm
Lenght of the shadow 120 cm
Angle of the sun 50°11' = 50.194°
Distance to Ecole Lafontaine 7.4614° x 111.111 km = 829 km
Circumference : 829 km * 360° / (56,832°° - 50.194°) = 44959 km

Kerli’s team
Height of the gnomon 241,5 cm
Lenght of the shadow 348 cm
Angle of the sun 55°14' = 55.241°
First partner located on the equator
Latitude 00° 00' 00''
Angle of the sun 0°
Distance to equator 6416 km
Circumference : 6416 * 360 / (55.241-0) = 41812 km

Collège Antonin Perbosc, Tarn et Garonne, France
44°08'N=44.133° & 1°15'E=1.250°E)

We had a sunny day for the equinox measurements

We used two gnomons of 100cm and 50 cm high.

With the gnomon of 50cm we realized an animation of the shadow of the gnomon

You can see the original video there:

European Association for Astronomy Education , Eratosthene groupspace

With the 100cm gnomon we made a precise measurement of the length of the shadow at solar noon : 97cm

angle of the sun : 44.128°

Latitude of Lafrançaise : 44°08’=44.133°

We have chosen a virtual partner located on the equator

Distance to equator 44.1333° x 111.111 km = 4904 km

Circumference : 4904 * 360 / 44.128 = 40007km

final report of september 2007
final report of june 2007
Matthew and Peter Sowerbutts, Adelaide South Australia

Hello my name is Matthew. I am 9 and I live in Adelaide South Australia. It is very hot right now and at the moment we are having a drought.

Longitude is 138 degrees 39.7 minutes East
Latitude is 34 degrees 51.7 minutes South

I am homeschooled with my 3 brothers- Peter 12, Christopher 7 and Anthony 4. I have an older brother and sister who go to school.

Sydney is one of the best known cities in Australia. Adelaide is smaller but is also a great place to live. We have hundreds of Fairy Penguins on Granite Island. In the evening they come out of the sea and walk across the paths to get to their nests.

During the first week of the project we did several things to get ready.

1. We read the book The Librarian Who Measured the Earth. We learned how Eratosthenes used shadows and angles to measure the circumference of the earth more than two thousand years ago.

2. We made a shadow clock. We used a pencil standing upright on a piece of paper. We placed it outside in the sun and recorded the length of the shadow cast by the pencil. We measured the length each half hour
for a few hours each side of noon. By finding the shortest shadow we discovered the direction of North and the approximate time of local noon. This turned out to be 1.20pm.

3. We looked up on the internet and found some useful information
(a) Our exact longitude and latitude for Windsor Gardens South Australia- Latitude 34.86° South
Longitude138.66° East
(b) Listing of exact times of local noon for Adelaide for every day of the year. 1.23pm was the
exact time for March 21st
(c) That between each degree of Latitude there was approximately 111km.
(d) That on March the 21st the angle of the sun was zero at the equator.

4. We got our equipment ready
Metre Ruler
Library bookend to keep our ruler at 90°
Tape to attach ruler to bookend
Tape measure
Paper for shadow to fall on

On March 21st
We went outside and measured the shadow length of the metre ruler every minute for about 5 mins each side of local noon (1.23pm). We used a measuring tape with millimeter divisions. The measurement was difficult to get exactly due to the shadow being fuzzy at the end and the ruler wobbling in the slightest breeze. We did our best and got 72.5 cm.


1. We read the book Sir Cumference and the Great Knight of Angleland and practiced measuring
angles with a protractor.

2. We got a big piece of paper and drew in the metre ruler and the shadow. Then we had to join them up to make a triangle. This was a bit difficult as we didn’t have anything long enough so
we used a long board and the metre ruler. We measured the angle between the top of the ruler and the line joining the top of the ruler to the end of the shadow. We used a protractor with the
smallest measure being one degree. We got 36 ° as our sun angle.

3. Circumference measurement. Then we partnered with the equator as we knew the sun angle
there was zero. We used our latitude 34.86 ° South and our knowledge that we could multiply
this by 111km to find our distance from the equator. We calculated approximately 3900kms.
This was the distance of our wedge. As our sun angle was 36 ° that made 10 wedges to make up
a full earth of 360 °. Multiplying 3900 by 10 gave a circumference of 39000kms. This was
slightly different from the actual circumference of about 40,000kms but quite good considering
the accuracy of our measuring equipment

4. We looked at everyone else’s data on the Noon-day site. We got out our world map and using the
latitude and longitude measures we marked all their positions.
We choose 3 other groups to partner with: Xiamen International School China
College Antonin Perbosc France
Arsenault Homeschool USA
To work out the size of each wedge we added our degrees of latitude together and multiplied by
111km. This gave the distance as if we had moved each of the other schools across to our
longitude and then measured directly North.
To work out the number of wedges we added our 2 sun angles together and divided it into 360.
We then calculated the circumference by multiplying the distance of each wedge by the number
of wedges.

Circumference results: With- Xiamen International School China 40,817kms
College Antonin Perbosc France 39,456kms
Arsenault Homeschool USA 39,095kms