Clavius

Christopher Clavius

Born: 1537 in Bamberg (now in Germany)
Died: 2 Feb 1612 in Rome (now in Italy)

Previous (Chronologically) Next     Biographies Index

Previous ( Alphabetically) Next          Welcome page
Christopher Clavius was a Jesuit astronomer who helped Pope Gregory XIII to introduce what is now called the Gregorian calendar.

The Julian leap-year rule created 3 leap years too many in every period of 385 years. As a result, the actual occurrence of the equinoxes and solstices slowly moved away from their calendar dates. The date of the spring equinox determines the date of Easter so the church began to press for reform.

Clavius proposed that Wednesday, Oct. 4, 1582 (Julian) should be followed by Thursday, Oct. 15, 1582 (Gregorian). He proposed that leap years occur in years exactly divisible by four, except that years ending in 00 must be divisible by 400 to be leap years. This rule is still used today and is so accurate that no further reform of the calendar will be necessary for many centuries.

Viète did not like Clavius's calendar and the people of Frankfurt rioted against mathematicians and the Pope who, they believed had conspired together to rob them of 11 days.

Although Clavius produced little mathematics of his own he did more than any other German scholar of the 16th Century to promote a knowledge of mathematics. He was the first, however, to use the decimal point.

He was a gifted teacher and writer of textbooks. His arithmetic books were used by many mathematicians including Leibniz and Descartes.

The picture above is from a engraving made from a portrait from life.

References elsewhere in this archive:

Tell me about the errors in the Julian calendar

Other Web sites:

Rice University, USA
Clarke University, USA

References:

  1. Dictionary of Scientific Biography
  2. C Sommervogel, Bibliothèque de la Compagnie de Jésus II (Brussels-Paris, 1891).
  3. C Naux, Le père Christophore Clavius (1537-1612) : Sa vie et son oeuvre I L'homme et son temps, Revue des Questions Scientifique 154 (1983), 55-67.
  4. J M Lattis, Between Copernicus and Galileo : Christoph Clavius and the collapse of Ptolemaic cosmology (Chicago, 1994). 
Previous (Chronologically) Next     Biographies Index

Previous ( Alphabetically) Next          Welcome page

History Topics Index              Famous curves index

Chronologies                           Birthplace Map

Mathematicians of the day  Anniversaries for the year

Search Form   Simple Search Form   Search Suggestions
JOC/EFR February 1996