Howard’s personal friends connected him to prominent eighteenth-century public figures. Howard’s close personal friend Richard Price became a minister, moralist, philosopher, and political writer with numerous influential connections by the 1770s. In the early 1760s, Price posthumously edited his friend Thomas Bayes’ manuscripts on the theory of probability, which were then published in the Transactions of the Royal Society. In 1771, Price became friends with William Petty, the second earl of Shelburne and prominent political figure who served in key British government positions, including Prime Minister in 1782.^ Price was a close personal friend of Joseph Priestley, one of the leading English natural philosophers of the eighteenth-century. Price also knew well Benjamin Franklin, the inventor, natural philosopher, and U.S. founding father. Franklin had sponsored Price for fellowship in the Royal Society in 1767. Price also had ongoing correspondence with Thomas Jefferson, John Adams, Turgot, Mirabeau, La Rochefoucauld, Thomas Belsham, and Adam Smith, among others. According to Benjamin Franklin, Price provided comments on sections of Smith’s drafts for The Wealth of Nations. Price also corresponded with Benjamin Rush, a leading member of Philadelphia society and a prominent proponent of penal reform in the U.S. Re-enforcing his personal relationships, Price was a member of the “Honest Whigs” club, which met regularly for discussion and included many intellectually and politically prominent figures.^ Price and Howard had a common, dissenting religion and a shared enthusiasm for science. By the mid-1770s, many of Price’s friends surely were also knew Howard.

Howard had other personal connections to London intellectual circles. As a young adult, Howard had lived from about 1749 to 1756 in Stoke Newington, about four miles north of the City of London. Many prominent dissenters lived in this area.^ One who lived nearby was John Canton. Canton was a leading English physicist who had won membership and a high honor from the Royal Society in 1750. Canton was among the four sponsors of Howard’s successful application for membership in the Royal Society in 1756. In 1764, Howard addressed observations on temperature to John Canton.^ In a letter to Richard Price in 1770, Howard in closing asked Price to “remember me” to “Mr Canton.”^ Canton, like Price, was a member of the “Honest Whigs” club.

Howard was also friends with John Fothergill, a Quaker, a doctor, and also a leading member of the Royal Society. Fothergill testified about prison health conditions to the House of Commons on Mar. 4, 1774, the same hearing that Howard testified. In 1776, Fothergill published, under the name “Philanthropos,” a letter in a London paper (The Gazetteer) urging reform in the employment of convicts.^ This is the same subject and spirit of Howard’s efforts. Howard accepted a position as superintendent for the construction of penitentiaries under the Penitentiary Act of 1779 on the condition that his friend Fothergill also be appointed a superintendent.^ John Coakley Lettsom, a physician protégé of Fothergill’s, was also one of Howard’s friends. Lettsom in 1772 published Reflections on the General Treatment and Cure of Fevers.^ Fevers were a widely recognized problem in jails (‘gaol fever‘).

Howard apparently was also friends with William Watson and John Ellicott, both of whom were prominent experimental philosophers and members of the Royal Society. Howard addressed observations on temperature to Watson in 1767. Howard letter began:

When I had the pleasure of seeing you in London, you thought some explanation of the paper, upon the heat of Bath-waters, necessary.^

That suggests that Howard had enough of a relationship with Watson to consult with him informally. Ellicott sponsored Howard’s membership in the Royal Society in 1756. Ellicott, who earned a living as a clockmaker, was known for work on temperature-compensated pendulums. Howard’s interest in measuring temperature’s was probably shared with Ellicott.