(2) Such notice shall state the particulars of any damage, ordered to be done or, in the case referred to in section 6, sub- section (3), done in exercise of any of the powers conferred by the said section, and the particulars of any restrictions attaching to the land under section 7, and shall require all persons interested in the land to appear personally or by agent before the Collector 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 land and the amount and particulars of their claims to compensation for damage to such interests and their objections (if any) to the measurements made under section 8. The Collector may in any case require such statement to be made in writing and signed by the party or his agent.