It was not to be. He was sentenced to death for returning from transportation, a fate which was then commuted to transportation for life. This time, as before, there was a specific destination mentioned, but this time it was America.^[24] Part of a defiant attempt to get the Americas to again accept British offenders, Limpus was embarked on the Mercury, a ship which, following in the wake of the earlier Swift , would try to disembark convicts in the rebellious colonies. The subterfuge was that they claimed to be destined for Nova Scotia, but would then put in to Baltimore, Maryland, announcing that they were too short of water or provisions to make the more northerly destination.^[25] And so Thomas Limpus again embarked on a ship, this time not as a working member of the crew as he had hoped and planned, but once more as a captive held below decks.

This voyage was an attempt by the British government to return to the past, to revert to paying private contractors to remove convicts sentenced to transportation who would then have a fiscal stake in their labour power. Before the American Revolution, banished criminals had been privately owned by masters in the Americas, with many convict ships selling their labour power to the highest bidder after arrival. Although their situation was never directly akin to that of African and African-American slaves, there was far more similarity in the intention of the voyages. Both convict transports and slave ships transported men, women and children to labour elsewhere, and sold them after arrival to those needing labourers.^[26] For those engaged as captain and crew of such vessels, part of their job was to deliver the ‘goods’ in such a condition that they would return the best price.

The contractor for the Mercury, George Moore, had the same scheme in mind. He had arranged to take the prisoners, Limpus included, with the idea of profiting financially from their export. In fact it was to prove a gross miscalculation, with the Mercury not permitted to disembark its prisoners at any of its intended ports of call. The authorities in Maryland were still smarting from an earlier attempt to pass off convicts from the Swift as indentured servants and refused to let it land its passengers.^[27] It then sailed for the Honduras Bay settlement in Central America, where despite an acute need for additional labour, the convicts were once again unwanted, the settlers fearing that they ‘would damage the credit and character of the country’.^[28] Moore’s gamble had not paid off, but for those who sailed on the Mercury their experiences of the voyage, until its disastrous end, would have been similar to earlier generations of criminals sent to the Americas. The sea crossing was designed to deliver much needed workers and to create a profit for the contractors. The punishment was in the loss of control over their personal autonomy and the fruits of their future toil, and for this they had to be prepared for their ‘sale’ to a master.

For Thomas Limpus, however, whatever his experiences as a man being prepared for the sale of his labour power, they were short lived. He had in fact left the ship long before it reached Maryland and the Honduras Bay settlement. Only four days after the ship departed from England some of the convicts had mutinied and temporarily captured the vessel from the captain and crew. It is not clear what part Limpus took in these proceedings, but it is possible that his previous work aboard ships had given him just the kind of knowledge, and even possibly anti-authoritarian spirit, which the mutineers needed. The rebels first steered for Ireland and then Spain before finally coming to rest in Devon. There the majority, including Limpus, escaped.^[29]

Quickly recaptured, Limpus, along with many other of his fellow Mercury escapees, was provisionally imprisoned in Exeter gaol. However, this was not designed to take such a large sudden influx of inmates and was sorely overcrowded. Fearing that ‘infectious Distempers’ would break out, or that they would attempt a mass escape, and unsure where to banish them to, they were removed to the Dunkirk hulk.^[30] Limpus was again at sea, if this time anchored just offshore.

The government, of course, had not finished trying to banish Thomas Limpus. By a strange twist of fate, the place they had in mind was the one from which he had already escaped. Yet the experiences of Limpus and his fellow transports in Africa had obviously not gone completely unnoticed, because by this time transportation to Africa was considered to be a far worse fate than America. As the admiralty itself put it, ‘in the routine of Punishment’ Africa was ‘considered as next in degree to that of Death’.^[31] Even the authorities baulked at the punishment, questioning whether they should suffer ‘so severe a sentence as Transportation thither’.^[32] The problem, therefore, was clear. If convicts taken to Africa simply died, as so many had, or escaped, there was no justifiable objective. As Limpus’s earlier voyage on the Den Keyser had illustrated, there was nothing constructive in merely dumping men and women onto another continent. A sea crossing was not, in itself, what the convicts were sentenced to, the government had obviously decided. It had to be a means to an end; it had to be fulfilling part of a larger aim. In the end the admiralty advised the Mayor of Plymouth that a general sentence of banishment ‘beyond the seas’ would be the best solution for the recaptured Mercury mutineers like Limpus.^[33]