The headblock of the broadside depicts the figure of Britannia¹. "Touch" here means an assessment. It is a figurative use of the assessment of the purity of gold by means of a touchstone. [OED]

Breaking stone for road building was one of the tasks assigned to the inmates of workhouses. They were put on piece work. If they refused to work for the piece rate they were returned to the parish. Turnpike Trusts especially in southern England employed pauper labour. In 1810 The pioneering road builder John McAdam contended that 'women or men past hard labour' should be employed breaking stone. 'a woman sitting will break more limestone for a road that two strong labourers on their feet with long hammers in a given time'. Children were also employed.

Reference: Albert, William - The Turnpike Road System in England 1663 - 1840 (#Cambridge University Press, 1972