John Williams is 79 years old (birthdate: February 8, 1932).
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William John Wills was born on January 5, 1834 and died on June 28, 1861. This would have been 27 years old at the time of death or 176 years old today.
William John Swainson was born on October 8, 1789 and died on December 6, 1855. William John Swainson would have been 66 years old at the time of death or 222 years old today.
William John Macquorn Rankine was born on July 5, 1820 and died on December 24, 1872. William John Macquorn Rankine would have been 52 years old at the time of death or 191 years old today.