Measurements

eTwinning and eTwinning+ schools (7)

| Aigio | Athens | Busteni | Has | Montcuq | Malovat | Nis |

America (3)

| Chivilcoy | Del Castilho | Méier |

On december solstice the Sun at the vertical of Capricorn Tropic at solar noon

All the measures on 18, 19, 20 , 21 and 22 december are available

The calculations are made with  the Capricorn tropic

The 2 schools in Rio de janeiro (Méier and Del Castilho) are too close to the tropic to have an accurate calculation of the circumference.