Concept of shape of the Earth.
Bedford level test:
test:Another similar test is done on Bedford Canal in England; In this case, three pillars on the canal are placed at equal elevations on the canal at a distance of 5 kilometers,
and if three nodes from one end see the middle of the twenty-six high ground plane In this case, you did not think it was proved that the earth is round by the experiment.
Pole stars: 
Pole stars in the North Pole are found to be in the 90°(degree) angle, in the direction of the star Earth's pole axis, this angular value decreases in the lower latitudes while the pole star of the molecule generates 0°(degree) angle with the administrator and the difference in the angular properties of the stars is that the earth is golakata easily If you can.
[(In your hands) You can also test such kind of tests in your school on a canal, for this you need three buses in front and a binocular.]
Have a Good Life......