Section 26. On or before the sixth week preceding any term of grand or trial juror service, the office of jury commissioner may summon additional grand or trial jurors if it appears from the returned juror confirmation forms that the number of previously summoned jurors who will report for service will be inadequate for the needs of the court. Any juror who is summoned under this section shall return a duly completed and signed confirmation form within ten days of its receipt by him. Any grand or trial juror summoned under the provision of this section from whom the office of jury commissioner has not received a duly completed and signed juror confirmation form by the third week preceding the term of service for which he was summoned shall be summoned a second time. The second summons shall have the same content and form as the first summons except the words ''second summons'' shall appear prominently on the face of the summons. The second summons shall be sent by first-class mail, registered mail, or served by a sheriff or constable. A juror who receives a second summons shall return a duly completed and signed juror confirmation form within five days of its receipt.