 Bald was a firm supporter of the Earl of Shaftesbury's Mines and Collieries Bill of 1842 that prohibited the employment of women and girls in mines and sought to regulate the employment of boys and improve safety conditions in the mines.Testimony of female coal bearers he had collected in 'An Inquiry into the condition of those women who carry coals underground in Scotland, known by the name of Bearers' (1808) had been used in the Children's Employment Commission earlier that year.Bald's obituary published in The Gentleman's Magazine, wrote that alongside Lord Ashley, the Earl of Shaftesbury, he did much to stop the employment of women 'bearers' in mines and to generally improve the condition of the mining community.