Section 4103. Issues triable by a jury revealed at trial; demand and waiver of trial by jury

When it appears in the course of a trial by the  court
  that  the  relief required, although not originally demanded by a party,
  entitles the adverse party to a trial by jury of certain issues of fact,
  the court shall give the adverse party an opportunity to demand  a  jury
  trial  of  such  issues.  Failure  to  make  such demand within the time
  limited by the court shall be deemed a waiver of the right to  trial  by
  jury. Upon such demand, the court shall order a jury trial of any issues
  of fact which are required to be tried by jury.