If the taking of an account, or the proof of a fact, or the assessment of damages, be necessary to enable the court to pronounce judgment upon a failure to answer, or after a decision of an issue of law, the court may, with the assent of the party not in default, take the account, hear the proof, or assess the damages; or may, with the like assent, refer the same to a referee, master, or commissioner, or may direct the same to be ascertained or assessed by a jury. If a jury be ordered, it shall be on or after the day on which the action is set for trial. This section shall not be construed to impair the right of a party to a jury if he appear at the trial by himself or attorney, and demand the same.