A general view of the coal trade of Scotland : chiefly that of the river Forth and Mid-Lothian : to which is added, an inquiry into the condition of the women who carry coals under ground in Scotland, known by the name of bearers : with an appendix, in which a review of the trade is taken to the present period, since the treatise was first published in 1808 : and a statement given of the steps lately taken by government, with the view of placing the coal trade under an excise : the effects of which are fully considered / by Robert Bald.