Meaning of phrase " two-forty as his speed" in carol "Jingle bells"

Posted by Sykim on December 18, 2000

As titled, I want to know the meaning or the orgin of the phrase "two-forty as his speed" shown in the famous carol song "Jingle bells".

Please help me.
A guy from Korea.

• I'll elaborate my question sykim 12/18/00
  • 2 minutes and 40 seconds! Bruce Kahl 12/18/00