He had however leisure and opportunity for his other studies and in 1795 he published observations on the increase of infidelity and he continued his Church History from the fall of the Western Empire to the reformation.
In the spring of 1796 he spent three months at Philadelphia and delivered there a set of discourses on the Evidences of Revelation, which he composed with a view to counteract the effect produced by the writings of unbelievers, which, as might be expected, was very great in a country where rational opinions in religion were but little known, and where the evidences of revelation had been but little attended to. It was a source of great satisfaction to him, and what he had little previous reason to expect, that his lectures were attended by very crowded audiences, including most of the members of the congress of the United States at that time assembled at Philadelphia, and of the executive officers of the government. These discourses which, in a regular and connected series, placed Christianity, and the evidences of its truth, in a more clear and satisfactory point of view than it had been usually considered in this country, attracted much attention, and created an interest in the subject which there is reason to believe has produced lasting effects. My father received assurances from many of the most respectable persons in the country, that they viewed the subject in a totally different light from what they had before done, and that could they attend places of worship, where such rational doctrines were inculcated, they should do it with satisfaction.
As my father had through life considered the office of a Christian minister as the most useful and honourable of any, and had always derived the greatest satisfaction from fulfilling its duties, particularly from catechizing young persons, the greatest source of uneasiness therefore to him at Northumberland was, that there was no sufficient opportunity of being useful in that way. Though he was uniformly treated with kindness and respect by the people of the place, yet their sentiments in religion were so different from his own, and the nature and tendency of his opinions were so little understood, that the establishment of a place of Unitarian worship perfectly free from any calvinistic or Arian tenet, was next to impossible. All therefore that he could do in that way was, for the two or three first years, to read a service either at his own or at my house, at which a few (perhaps a dozen) English persons were usually present, and in time, as their numbers increased he made use of a school room near his house, where from twenty to thirty regularly attended, and among them some of the inhabitants of the place, who by degrees began to divest themselves of their prejudices with respect to his opinions. However small the number of persons attending, he administered the Lord’s supper, a rite upon which he always laid particular stress.
In the Autumn of 1795 he had the misfortune to lose his youngest son, of whom being much younger than any of his other children, and having entertained the hopes of his succeeding him in his Theological and Philosophical pursuits he was remarkably fond. He felt this misfortune the more severely as it was the first of the kind he had experienced, and particularly as it had a visible effect upon my mother’s health and spirits. He was however so constantly in the habit of viewing the hand of God in all things, and of considering every occurrence as leading to good, that his mind soon recovered its accustomed serenity, and his journey to Philadelphia mentioned above and the success which attended his first exertions in the cause of, what he deemed, pure and genuine christianity, led him to look forward with cheerfulness to the future, and gave him an energy in his pursuits, which was never exceeded in any part of his life. It was the same habit of viewing God as the author of all events, and producing good out of seeming evil, that enabled him to support himself so well under the greatest affliction that could possibly have befallen him, viz. the loss of his wife, my mother; who through life had been truly a help meet for him; supporting him under all his trials and sufferings with a constancy and perseverance truly praise worthy, and who as he himself, in noting the event in his diary, justly observes, “was of a noble and generous mind and cared much for others and little for herself through life.”
In the period between the above very afflicting events, though his conveniences for experimenting were not increased, owing to his house, and particularly his laboratory not being finished, he wrote a small treatise in defence of the doctrine of Phlogiston, addressed to the Philosophers in France. He likewise composed a second set of discourses of a similar kind to those delivered in Philadelphia the preceding winter. He preached and printed a sermon in defence of Unitarianism, and printed the first set of discourses; he compleated his Church History; he made additional observations on the increase of infidelity chiefly in answer to Mr. Volney; and drew up an Outline of all the Evidences in favour of Revelation.
In the spring of 1797 he again spent two or three months in Philadelphia, and delivered a second set of discourses, but partly from the novelty of the thing being done away, partly from the prejudices that began to be excited against him on account of his supposed political opinions, (for high-toned politics began then to prevail in the fashionable circles) and partly owing to the discourses not being so well adapted for a public audience, though necessary to set the comparative excellence of Christianity in its true light, they were but thinly attended in comparison to his former set. This induced him to give up the idea of preaching any more regular sets of discourses. He however printed them, as likewise a sermon he preached in favour of the Emigrants. He also composed at this time a third and enlarged edition of his Observations on the increase of infidelity, a controversy with Mr. Volney, a tract on the Knowledge of a Future state among the Hebrews, which, with the works he composed the year before, he printed as he found means and opportunity. He revised his Church History, began his Notes on the Scriptures, and his Comparison of the Institutions of Moses with those of the Hindoos.
Towards the end of 1797 and not before, his library and laboratory were finished. None but men devoted to literature can imagine the pleasure he derived from being able to renew his experiments with every possible convenience, and from having his books once more arranged. His house was situated in a garden, commanding a prospect equal, if not superior, to any on the river Susquehanna, so justly celebrated for the picturesque views its banks afford. It was a singularly fortunate circumstance that he found at Northumberland several excellent workmen in metals, who could repair his instruments, make all the new articles he wanted in the course of his experimenting, as well as, he used to say, if not in some respects better than, he could have got them done in Birmingham; and in the society of Mr. Frederick Antis, the brother of Mr. Antis in England, and uncle of Mr. Latrobe the engineer, he derived great satisfaction. Mr. Antis was a man of mild and amiable manners, he possessed a very good knowledge of Mechanics the result of his own observation and reflection, and a fund of knowledge of many things which my father frequently found useful to resort to. The situation of Northumberland became abundantly more convenient than it was when he first came to the place. From there being no regular public post, there was now established a post twice a week to Philadelphia, and answers could be received to letters within a week, and the communication so much increased between the two places, that the price of the carriage of goods was reduced from 11s.-3d. to 6s. per Cwt. the distance being 132 miles.
Thus conveniently situated, he resumed the same kind of life he led at Birmingham, experimenting the greater part of the day, the result of which he published in the Medical repository of New-York. Having compleated his Church History, he finished his Comparison of the Institutions of Moses with those of the Hindoos. He likewise proceeded as far as Leviticus in the design he had formed of writing Notes on all the books of Scripture, and made some remarks on the origin of all religions by Dupuis, but the greater part of the time that he spent in theology this year, was employed in recomposing the Notes on the New-Testament, which were destroyed at the riots.
In the course of the year 1799, he finished his Notes on all the books of Scripture, he published his Comparison of the Institutions of Moses with those of the Hindoos, he likewise printed his Defence of the doctrine of Phlogiston above mentioned, and the greater part of each day in the summer was employed in making the additional experiments he had projected.
It was in the year 1799, during Mr. Adams’s administration, that my father had occasion to write any thing on the subject of politics in this country. It is well known to all his friends, that politics were always a subject of secondary importance with him. He however took part occasionally in the conversations on that subject; which every person has a right to do, and which, about the time my father left England, no person could avoid doing, as the subject engrossed so large a part of the conversation in almost every company. He always argued on the side of liberty. He was however in favour only of those changes that could be brought about by fair argument, and his speculations on the subject of British politics did not go further than a reform in Parliament, and no way tended, in his opinion, to affect the form of government, or the constitution of the kingdom, as vested in Kings, Lords and Commons. He used frequently to say, and it was said to him, that though he was an Unitarian in Religion he was in that country a Trinitarian in politics.