When parties did what they were already contractually obligated to do, they could not demand additional compensation.The court held that the contract was not supported by adequate consideration because it was based solely on libelants' agreement to render the exact services that they were already obligated to perform.Appellant agreed to the demands of the workmen out of necessity. The new agreement was based solely upon the workmen’s assent to render the exact services that they were already under contract to render. Hence, the new agreement was not supported by new consideration and therefore unenforceable.