1>the French astronomer Jean Picard became the first person to accurately measure the length of a degree of a meridian and
used that to calculate the size of Earth.
-lack of tense agreement between 'to measure' and 'used'
-the pronoun 'that' is vague (not clear reference)
2>the French astronomer Jean Picard became the first person to accurately measure the length of a degree of a meridian and
made use of it
in the calculation of the size of Earth.
-lack of tense agreement between 'to measure' and 'made'
- 'in the calculation of the size of Earth' is awkward and wordy.
3>the French astronomer Jean Picard
made the first accurate measurement of the length of a degree of a meridian and
used it to calculate the size of Earth.
4>the first accurate measurement of the length of a degree of a meridian
was made by the French astronomer Jean Picard, and he used
that to calculate the size of Earth.
- passive voice is used
-the pronoun 'that' is vague (not clear reference)
5>the length of a degree of a meridian was
first accurately
measured by the French astronomer Jean Picard
, who calculated the size of Earth with it.
-'first' gives a different meaning (as if : the length was at the beginning measured by ... then something new happen)
- passive voice is used
- comma should be used before 'who'.
IMO C