after completing the third volume cantor realised that, at the age of 69, he was not up to the task of completing another volume, so at the congress of 1904 in heidelberg he organised a team with nine further contributors to collaborate on the fourth volume.
Capitalize this past sentence correctly.
After completing the third volume Cantor realised that, at the age of 69, he was not up to the task of completing another volume, so at the Congress of 1904 in Heidelberg he organised a team with nine further contributors to collaborate on the fourth volume.