High-precision radiocarbon measurements of contemporaneous tree-ring wood from the British Isles and New Zealand: AD 1850-950.

The University of Waikato, Hamilton, New Zealand and The Queen's University of Belfast, Northern Ireland radiocarbon dating laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus petraea) from Great Britain and cedar (Libocedrus bidwillii) and silver pine (Lagarostrobos colensoi) from New Zealand. The results show an average hemispheric offset over the 900 yr of measurement of 40±13 yr. This value is not constant but varies with a periodicity of about 130 yr. The Northern Hemisphere measurements confirm the validity of the Pearson et al. (1986) calibration dataset.

Calibration of the Radiocarbon Time Scale for the Southern Hemisphere: AD 1850-950

We have conducted a series of radiocarbon measurements on decadal samples of dendrochronologically dated wood from both hemispheres, spanning 1000 years (McCormac et al. 1998; Hogg et al. this issue). Using the data presented in Hogg et al., we show that during the period AD 950-1850 the 14C offset between the hemispheres is not constant, but varies periodically (~130 yr periodicity) with amplitudes varying between 1 and 10‰ (i.e. 8-80 yr), with a consequent effect on the 14C calibration of material from the Southern Hemisphere. A large increase in the offset occurs between AD 1245 and 1355. In this paper, we present a Southern Hemisphere high-precision calibration data set (SHCal02) that comprises measurements from New Zealand, Chile, and South Africa. This data, and a new value of 41 ± 14 yr for correction of the IntCal98 data for the period outside the range given here, is proposed for use in calibrating Southern Hemisphere 14C dates.

Near-infrared spectroscopy of PKS 1549-79: a protoquasar revealed?

We present a near-infrared (near-IR) spectrum of the nearby radio galaxy PKS 1549-79 (z = 0.153). These data were taken with the aim of testing the idea that this object contains a quasar nucleus that is moderately extinguished, despite evidence that its radio jet points close to our line of sight. We detect broad Paalpha emission (FWHM 1745 +/- 40 km s(-1)), relatively bright continuum emission, and a continuum slope consistent with a reddened quasar spectrum (3.1 <A(V) <7.3), all emitted by an unresolved point source. Therefore we conclude that we have, indeed, detected a hidden quasar nucleus in PKS 1549-79. Combined with previous results, these observations are consistent with the idea that PKS 1549-79 is a young radio source in which the cocoon of debris left over from the triggering events has not yet been swept aside by circumnuclear outflows.

Exile or emigrant? Female ex-prisoners who left Ireland 1850-1921

In the popular mind, the concept of 'emigration' usually refers to people voluntarily leaving one country to go to another in search of a new and better life. It presupposes some degree of choice, although it is accepted that for many emigrants, such as those who left Ireland during the nineteenth century, there were few incentives to stay at home. Current scholarship on voluntary and forced movements of people demonstrates that the distinction between the categories of 'voluntary emigrant' and 'forced exile' is often blurred. Orm Overland's study of refugee communities in the United States highlights the fact that, although the differences between the 'emigrant' and the 'exile' may be clear in extreme cases, this is not always true, as there may be 'pressing political or economic reasons behind a decision to emigrate'. Migration scholars Jan Lucassen and Leo Lucassen also question the adequacy of conceptual models of migration based on what Lindsay Proudfoot and Dianne Hall refer to as the 'straightforward binarism between free and unfree emigration'. The questions raised by these scholars are very relevant to the study of Irish people who left their country during the second half of the nineteenth century immediately after they had been discharged from prison or from Dundrum. Their stories are discussed here against a background of substantial scholarship on emigration from Ireland and on the criminal justice system within Ireland. According to David Fitzpatrick, at least eight million men, women and children emigrated from Ireland between 1801 and 1921. This large-scale movement of people was generally characterised by the voluntary emigration of individuals who funded their own passages. However, it also included schemes of assisted emigration, funded variously by governments, landlords, the poor law authorities, earlier emigrants, and philanthropists. In addition, it included people who were transported from Ireland by means of the criminal justice system a practice that had originated in the seventeenth century. What is less well known is that after the end of transportation from Ireland to eastern Australia in 1853, to Bermuda in 1863 and to Western Australia in 1868, Irish convicts continued to be channelled towards emigration by being offered early release if they agreed to leave Ireland. These people, and especially the women among them, are the subject of this article.