Again, the earth is not a perfect sphere, but a spheroid, and there is a factor called precession, due to the attraction on the protuberant mass at and towards the equator.
If the earth were a perfect sphere, its orbit round the sun a perfect circle, and the equator coincided with the ecliptic, there would be no seasons.
They would, were the earth a perfect sphere; but it is not exactly such, being somewhat protuberant about the equator, and flattened towards the poles.
If, then, the earth is not a perfect sphere, but prominent at the equator, and depressed at the poles, would not a body weigh heavier at the equator than at the poles?
What would have been a consequence of the centrifugal force, had the earth been a perfect sphere?
The effect in this last-named latitude is the same as if the earth were a perfect sphere.
If the sea-level over the entire earth were a perfect sphere, an important consequence would follow--the length of a degree of the meridian would be everywhere the same.
If the earth were a perfect sphere, precession would be inexplicable.
If the earth were a perfect sphere, then the attraction would be the same at every part, and the body would fall through the same distance everywhere.
The measured lengths of the degrees enable us to see to what extent the shape of the earth departs from a perfect sphere.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "perfect sphere" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
