...the [English] crown, desperate for new sources of patronage and revenue in the 1630's, was able to exploit [loopholes]. Industrial corporations were created or transformed to operate patents that conferred monopoly powers, at the price of an annual rent or pro rata payment to crown. Major items of consumption - salt, soap, starch, coal, for example - rose dramatically in price as monopolists sought to recoup the rents and premiums demanded by the government and to extract high profits while their political luck held. The practicioners of some trades were barred from exercising their legitimate occupation except on the payment of fines, or they paid harsh penalties for refusal.