(1) When any act or omission would, if a person were under a certain age, be an offence punishable under this Act and such person is, in the opinion of the court, prima facie under such age, the burden shall be on the accused to prove that such person is not under such age.
     (2) A declaration in writing by a medical officer not below the rank of a Civil Assistant Surgeon relating to an employee that he has personally examined him and believes him to be under the age stated in such declaration, shall, for the purposes of this Act and the rules made thereunder, be admissible as evidence of the age of that employee.