receive full-time education at an educational institution, the Commissioner may, having due regard to the circumstances of the case and taking into consideration the amount of assistance from any other source towards the further education of that child, award an allowance— (a) if that child attends at a university, at a rate not exceeding eight hundred and fifty-six dollars per annum; (b) if that child attends at an educational institution other than a university, at a rate not exceeding eight hundred and fifty-six dollars per annum or, if the Commissioner considers that there are special circumstances warranting a greater allowance, not exceeding five hundred and ninety-five dollars per annum. (2) Subject to subsection (3), an allowance in terms of subsection (1) shall be payable with effect from such date and for such period as may be fixed by the Commissioner: Provided that payment of such allowance shall depend on the progress of the child at the educational institution being satisfactory to the Commissioner. (3) An allowance in terms of subsection (1) shall not be payable in respect of any period after the child attains the age of— (a) in the case of a child attending at a university, twenty-four years; (b) in the case of a child attending at an educational institution other than a university, twenty-one years: Provided that, if the Commissioner considers that there are special circumstances warranting the payment of the allowance or part thereof after the child attains the age specified in paragraph (a) or (b), as the case may be, the Commissioner may authorize the payment of the allowance or part thereof for such period as the Commissioner thinks fit. PART VII GENERAL 27 Medical boards (1) The Commissioner may from time to time request the Minister to appoint a medical board consisting of two medical practitioners for the purposes of this Act. (2) A member of a medical board who is not in the full-time employment of the State shall be entitled to be paid such remuneration and allowances as the Minister may in his case fix. 28 Assessment of earnings (1) Subject to subsections (2) and (4) of section twenty-four, where any compensation payable in terms of this Act is to be calculated in relation to the earnings of any person, the Commissioner shall assess the earnings of that person by taking into account— (a) in the case of a person employed by another, the income, either real or potential, including the value of free quarters, received by him in respect of such employment and any other income which the Commissioner considers to be relevant; and (b) in the case of a person not employed by another, any income of his which the Commissioner considers to be relevant; and where, in the opinion of the Commissioner, it is necessary to do so, the Commissioner may, for the purpose of calculating the earnings of that person immediately prior to the date of his injury or death, as the case may be, calculate his average income over such period, not exceeding four years, immediately prior to that date, as the Commissioner considers to be equitable in the circumstances. (2) In assessing, in terms of subsection (1), the earnings of a person who, at the time of his injury or death, was under the age of twenty-five years or was employed under a contract of apprenticeship or learnership, the Commissioner shall calculate the income received by him or which would have been received by him had he been employed as being the income which, had he not been injured or died, he would, in the opinion of the Commissioner, probably have been receiving from employment— (a) four years after the date of his injury or death; or