A

Population Explosion

In the seventeenth century, Ireland was one of the more thinly populated regions of western Europe. Population growth was typically slow and subject to reversals owing to war, harvest failure, famine, and disease. Modest population growth was apparent during the first four decades of the eighteenth century but there was a savage setback between 1740 and 1741 as a result of crop failure, bitterly cold weather, hunger, and famine diseases. By the end of that catastrophe the number of people on the island approximated only two million, much the same level as a half century earlier. But that picture of slow change in the numbers of families, households, and individuals inhabiting the island was to change dramatically and unexpectedly.

In the century between the 1740s and the 1840s Ireland experienced an explosive growth of population. In fact, the expansion was the fastest in Europe, with the possible exception of Finland (another thinly populated country with large reserves of wasteland). In 1750, in round figures, there were two million inhabitants. By 1800 this total had swollen to five million. The mighty wave of population increase continued into the nineteenth century, reaching its highest level in 1845. By then the island was peopled by 8.5 million beings, a remarkable figure never achieved before or since.

An alternative way of expressing this headlong surge of population is to capture it in terms of proportional change on an annual basis. Before looking at the Irish figures, it is worth bearing in mind that a sustained population increase of more than 1 percent per annum is rapid by the standards of preindustrial societies. The most authoritative estimates for Ireland suggest an annual growth rate of 1.5 percent or more for the period 1753 to 1791, and 1.4 percent (possibly 1.6%) for the years from 1791 to 1821. In the poorest, most westerly province of Connacht reproduction was at its most exuberant, with the population increasing by close on 2 percent each year, on average, up to 1821.

So, why this astonishing turnaround in demographic fortunes? It certainly had nothing to do with an influx of people, as in the case of other immigration-prone societies. There was a small but significant outflow of people from Ireland, and Ulster in particular, during the eighteenth century. Between 1815 and 1845 perhaps a further 1.5 million Irish emigrated to Britain or North America. In view of this movement of population, the problem to be explained is all the greater.

INCREASED FERTILITY AS A CAUSE

Logically, there are only two remaining possible sources of population increase: a rise in births or a fall in mortality over time. The two are not of course mutually exclusive. Historians have tended to place the primary emphasis on increased births (or fertility). Change might have come about because of a variety of shifts in the economic and ecological systems of Irish society. First, there was the increasing use of the miracle food—the potato. The famous spud was not only nutritious: In the production of a given level of calories it was at least twice as economical in its use of land as other food sources such as oats or wheat (not to mention dairy or beef farming, which used land extravagantly). In effect, under a regime of potato cultivation much higher population densities became possible. Subdivision of holdings among two or more children also became feasible without threatening, at least for a generation or two, the viability of the farm holding. In addition, potatoes proved to be well adapted to the poorer soils, allowing reclamation of bog lands and mountainsides. This in turn allowed population to spill out onto the wastelands in a process of internal colonization of the countryside.

It is possible, as the pioneering work of Kenneth H. Connell suggested, that potato cultivation lowered the age at which men and, more importantly, women married in the second half of the eighteenth century. The argument is that the potato crop lowered the barriers to marriage by assuring young couples of at least a minimum subsistence, even when access to a patch of land was all that was available. In a noncontraceptive society early female marriage would have led inevitably to larger families. There is a small number of local studies that indicate that this is indeed what happened in the later eighteenth century but there is no comprehensive evidence as yet on age at marriage and how this may have changed over time. In addition to possible changes in the age at marriage, it is also possible that the proportions of the population that married increased over time as potato cultivation relaxed the restraints on the formation of households. Even more speculatively, a baby food of mashed potatoes and milk may have allowed children to be weaned at an earlier age. The effect on mothers would have been to shorten the sterile period after birth and thus boost fertility.

The potato also acted on mortality by helping prolong the lives of children and adults. It reduced mortality not only by virtue of its high nutritional content but also because it added a cheap and apparently reliable food to the people's diet. In time, of course, with a descent into monoculture, dependence on the potato would prove a source of vulnerability. But for at least the two generations after 1750, when it was used in conjunction with oatmeal, milk, or other foodstuffs, it must have added to the reliability of the food supply. Further influences favoring a decline in mortality in the century before the Great Famine of the 1840s may have included medical advances in the fight against infectious diseases, with smallpox perhaps as the only significant candidate for consideration. It is also possible that the virulence of infectious diseases naturally waned over time; if so, the reasons belong to the natural rather than to the social world.

SOCIOECONOMIC CONTEXT

But the social world was fundamental. The prerequisite to an ever-increasing population was an expanding economic base, as the early classical economists Adam Smith and the Reverend Thomas Malthus reminded their readers. The Irish economy experienced a long wave of expansion between the 1740s and 1815. Potato cultivation played its variety of roles. A rising demand for Irish agricultural produce on the British and overseas markets, in particular for labor-intensive products such as oats, wheat, butter, and pork, created livings for more and more people. Handicraft industry also expanded, most notably in Ulster, where the linen industry achieved spectacular gains. Manufacturing and subsistence farming coexisted side by side, multiplying the possibilities of making a living.

Ulster also illustrates the point that there was more to Irish population history than the potato. In this northerly province the potato never achieved the dominance that it attained in the south and west of the island. Oatmeal was used extensively in the people's diet, yet during the early decades of population growth it was Ulster that experienced the most rapid increase in numbers of any of the four provinces. Similarly, it may be noted that population growth was common to other European societies at the time, where cereals were the stable food. Clearly, then, pan-European rather than purely Irish forces were at play. Still, in explaining Ireland's place at the top of the European growth league, it is tempting to conclude that it was the potato that made the difference.

A DOWNWARD TREND

Irish population lurched forward in the century before the Great Famine, in a manner that had no precedent in Irish history. But it is also clear that at least three decades before that awful event, the rate of population growth was slackening and adjusting downward. The tragedy is that potato failure and famine struck at an inflated population before it had time to complete the adjustment to a new equilibrium between population and food resources.

SEE ALSO Agriculture: 1690 to 1845; Family: Marriage Patterns and Family Life from 1690 to 1921; Great Famine; Land Questions; Migration: Emigration from the Seventeenth Century to 1845; Population, Economy, and Society from 1750 to 1950; Potato and Potato Blight (Phytophthora infestans); Rural Life: 1690 to 1845; Subdivision and Subletting of Holdings; Town Life from 1690 to the Early Twentieth Century

Bibliography

Connell, Kenneth H. The Population of Ireland, 1750–1845. 1950.

Daultrey, Stuart, David Dickson, and Cormac Ó Grada. "Eighteenth-Century Irish Population: New Perspectives from Old Sources." Journal of Economic History 41, no. 3 (1981): 601–628.

Liam Kennedy