Contracting liability for workplace injuries: employer liable to compensate employees, with indemnity available from contractors. Where an employer contracts out work ordinarily part of its trade, the employer is liable to pay compensation to employees engaged in that work as if immediately employed by the employer, calculated with reference to the wages payable by the immediate employer. The employer paying compensation may be indemnified by the contractor or other persons from whom the employee could have recovered, with indemnity disputes settled by the competent authority; employees may instead recover directly from the contractor. The section does not apply to accidents occurring off premises under the employer's control.