Question

At the Bedford level canal area a famous experiment was carried out. How many poles were used and at what distance apart?

Options

• 3 poles, 5 km

• 2 poles, 10 km

• 4 poles, 5 km

• 3 poles, 10 km

Answer 1

3 poles, 5 km

Explanation:

In this famous experiment, three poles of equal height were fixed at intervals of 5 km along the canal. When viewed from one end of the canal, the middle pole appeared slightly higher than the other two. This observation proved that the Earth's surface is curved. If the Earth were flat, all three poles would have appeared at the same height in a straight line of sight. This experiment provided clear evidence that the Earth is not flat, but curved.