9. When any claim for compensation is made before the Collector in accordance with the last preceding section, the Collector shall issue a notice requiring all persons interested in the matter in respect of which compensation is claimed to appear personally or by agent before him at a time and place therein mentioned (such time not being earlier than fifteen days after the date of publication of the notice), and to state the nature of their respective interests in the property affected, and the amount and particulars of their claims to compensation for such interests.