Carew observes that the parishes in which the tin was worked were in a "meaner plight of wealth" than those which were agricultural. Vast amounts of tin were raised, but little of the profit stuck to the hands of the toilers in the mines.
Tinning was not carried on by large companies, but by small men; three or four would combine to take a set. They cut four turves at the bounds, paying a certain sum down to the Duchy or to the private owner of the land, as rent; and also owing a toll of the tin raised to the proprietor of the land. These small men were without capital, and they were constrained to borrow of Roberts, and he let them have the requisite money at a rate of interest we should consider extortionate. Queen Elizabeth was unable to borrow money of the estates of Holland under 25 per cent, and we may judge what would be the rate of interest demanded by the usurer of the working miner.
But that was not all. The miner did not pay the interest in cash, but in tin, and tin at the value pretty arbitrarily laid down by the moneylender, so that he had the adventurer in two ways. Nor was this indeed all. He often advanced to the miner not cash alone, but the tools for his trade, the timber for shoring up the shafts, and the machinery, such as it was, for pumping the water out of the mines.
There was an additional means of getting money, and also of acquiring lands. Carew gives us a curious account of the manner in which the London merchants of his time took advantage of any want of money Cornish gentry in London might experience in order to defray their expenses there, by binding them to furnish tin for money advanced, at great ultimate loss to the Cornish men. They also had their agents in Cornwall, who advanced money to the needy tinners, partly in wares and partly in money, upon agreement that they should furnish certain quantities of tin at the next coinage, by which the tinners experienced great loss.
With regard to the loans to the adventurers, Roberts possessed the inestimable advantage of being on the spot, and so prepared to supply them with the fuel and the capital they needed. But there were Cornish gentry who wanted to go to London, and desired loans to cover their expenses in town. They went to Roberts: he furnished the supplies. As may be well expected, these gentry did not make money in London, they became greatly impoverished there, and Roberts, we may infer, was able to take their estates, or large slices out of them, on the security of which he had made the advances.
How hard the work of the poor tinners was, on whom the usurers preyed, we learn from Carew. "In most places," he says, "their toyle is so extream, as they cannot endure it above four hours a day, but are succeeded by spels; the residue of the time they weare out at coytes, kayles, or like idle exercises."
Richard Roberts, the son of John, amassed great wealth, and was knighted 11 November, 1616. At this time he was threatened with prosecution by the Privy Seal for usury, and he only escaped trial by paying a bribe of £12,000. He bought a baronetcy of James I in 1621, and was created Baron Truro in 1625. One of the charges brought against Buckingham, when impeached in the House of Commons, was that he had received a bribe of £10,000 from Richard Roberts for negotiating for him his elevation to the Barony of Truro. This is confirmed by the deposition of Roberts himself (Calendar State Papers, 1677-8, p. 220; cf. 1625-6, p. 298).
Richard Roberts married Frances, daughter of John Hender of Botreux Castle or Boscastle, a co-heiress, and died in 1634. He was evidently a very shrewd and grasping man, and particularly desirous of pushing ahead and obtaining a position to which his only claim was wealth. By the marriages of father and son, the very plebeian family of Roberts brought strains of gentle blood into the veins of their descendants. He it was who built the stately mansion of Lanhydrock. He died 19th April, 1634, but was not buried at Lanhydrock till July 4th in the same year.
His son and heir John Roberts, second Baron Truro, was sent to be educated at Exeter College, Oxford. He entered as Gentleman Commoner in 1625, when aged seventeen, the year of his mother's death. At college, according to Wood, he "sucked in evil principles both as to Church and State."