Thomas was a corn merchant like his father, with warehouses in Cork, Limerick and Tralee.
With a rising population  England has been dependent on imported grain since the middle of the eighteenth century.  The Corn Laws imposed heavy duty on foreign grain. Since the Act of Union of 1800 Ireland had been regarded as part of England and grain imports free of duty. By 1832-4 the Irish grain harvest exceeded that of England. A port like Tralee in Co.Kerry was exporting upwards of 10,000 tons annually. The Kerry Evening Post of June 1834 reported "It is interesting to view the great number of corn stores now in Tralee, full every year of grain for exportation and to think back to the time thirty years ago when not a single corn store was to be seen in the town. In comparison to today Tralee was a miserable hamlet with little in the way of maritime trade, and the poor farmer had no other mode of making up his rent than by the produce of his half-starved cow and the labour of his wife." By 1852 there were 41 corn stores in Tralee. Thomas owned three of them.
Thomas continued to export corn throughout the famine years. According to a newspaper report headed "Limerick Intelligence" and dated July 1846, 1,663 barrels of oats were dispatched by Thomas from Limerick to London and 250 qrs.of oats & 20 tons of oatmeal from Galway to London. It is not yet established whether his depots were being guarded by British soldiers against looting by the starving masses as was common elsewhere. The british government  with an almost religious devotion to the policy of "Laissez faire" were reluctant to take any action to restrict the export of corn. 
In 1874 Thomas held 2800 shares in the Baltic company (trading in corn). "These (the shareholders) were the people who were reaping the rewards of the Baltic." writes Hugh Barty-King. 
In 1871 there are references to his ownership of 340 acres at Ballintemple, Cork
At his death Thomas owned 2,600 acres in Co.Kerry; 616 acres in Co.Cork; 842 acres in Co.Clare and 130 acres in Essex. This land was estimated to yield a gross income of £5,408 annually (£285,000 in today's money).   Source: Great Landowners of England and Ireland. 1883.
A family pedigree lodged with the college of arms starts with Thomas and can be found in Burke's Landed Gentry (18th edition, volume 3, 1972).
A memorial can be found in St Finn Barr's Cathederal, Cork.