When the clerk has commenced to call the roll of the council for the taking of a vote by "yeas" and "nays," all debate on the question before the council shall be deemed concluded, and, during the taking of the vote, no member shall be permitted to explain his vote, but shall respond to the calling of his name by the clerk by answering "yea" or "nay," as the case may be.
('69 Code, § 2-89)