William Smith and Ireland: Sources of Irish geological information on his geological map of 1820

William Smith's 1815 geological map shows the eastern margin of Ireland, but it is devoid of geological information. The scaled-down version published in 1820 provides a rudimentary representation of Irish geology with the granite regions of the Mourne and Wicklow Mountains prominent. The sources for this information were derivative coming from two maps published in the Transactions of the Geological Society of London in 1816 and 1819.