When services are to be rendered in a classified position of a temporary character and for a definite period, the appointing authority shall inform the Commission, stating the duration of such temporary employment, the rate of compensation and other conditions of such employment, and may select for such temporary employment one of the first three persons on an appropriate eligible list who are willing to accept such employment. Neither the acceptance nor declination of any such temporary employment shall affect the right of an eligible to certification for permanent appointment, nor shall acceptance confer any of the rights of promotion, transfer or reinstatement.