Twenty-two hundred years ago, the Greek scientist Eratosthenes measured the circumference of the Earth. This paper describes an experiment to replicate Eratosthenes' experiment with observers located in Australia and New Zealand. The most accurate circumference produced in the experiment described in this paper is 38,874?km, measured at Rosebud, Victoria, Australia, and Jimboomba, Queensland, Australia with an error of 2.9%. This exceeds the accuracy of Eratosthenes, although not of the modern recreation of his experiment between Syene and Alexandria. The experiment described in this paper might form a useful model for cooperation between schools in different countries.