Consider first population density between 1870 and ... correlate to total population. Compare Ireland, which looks like a bright red spot in the above map, with France, which appears to have ...

If you are interested in looking at this issue globally, I recommend Duncan Smith’s World Population Density interactive map, or the World ... and 160 for Northern Ireland.

This map shows the population Densities in 1841 and 1851, showing the number of persons per 100 acres. In 1841 there was very high levels of population density in the area encircling Lough Neagh ...