Physics Class day : 18 April 2007

We are two classes 1A and 1B at IISS G. La Pira Pozzallo of Lower Secondary School, a Nautical School. We are about 15 years. Our best estimate of Earth circumference was of 37333.84 km, as is shown below.

With an mean error of 6,74 %, and our best error was of 5,6 % and the worst case have been 8,0 %. We have performed our observation on days 19, 22, 23 March because 20th and 21st March it was impossible because of bad weather (sometime also in Sicily have clouds just for local noon!!!)

The instruments and the method we used are - The Solar Dial, to place the location of local meridian that you can see on picture below.

On this big sheet of paper we have drawing the position of the meridian to get the exact position of the Sun in its passage at local noon. In the picture is shown the meter stick through which we have measured the meter stick shadow and then we got the Sun ray angles.

We have realized that the error source are of different nature from the flatness of the ground and also of perpendicularity of meter stick . All our instruments are home made, our teacher have build years ago, we probably will have newer next occasion to participate at the Noon Project.

Hello to every one and if some one would proceed to exchange measurements with us, will be appreciated and welcomed.
—  Rocco G. Maltese Via Roma, 15 - 97016 Pozzallo (Rg) Italy +390932954752 - cell. +393289490530 Work: IISS "G. La Pira" Via E. Giunta - 97016 Pozzallo (Rg) Italy +390932953326