The eighth article was entitled: "Monthly and Annual Results of Meteorological Observations" for the years 1801, 1802, 1803.
In an appendix to his seventh article, he discusses the writings of certain Italian, French and German scientists, giving his reasons for differing with them on certain philosophical questions. His discussion is devoted largely to a consideration of certain laws of hydrostatics.
His "Observations on the eclipse of the sun, June 16, 1806" made in his private observatory on Union Hill, constitutes his tenth contribution to the publication mentioned above. This article gives a vivid account of the excited state of mind with which an astronomer awaits the time when nature affords favorable opportunities for investigating her mysteries. It also shows that this frontier scientist of Mississippi enjoyed in thought, as he could not by personal association, the companionship of the great thinkers of the world. These are his words:
"The moment of the expected impression approached and reflecting that this eclipse was to be seen all over Europe and North America which renders it a very important phenomenon for settling comparative longitudes, I conceived that all the zealous astronomers of both worlds were then looking with me at the great luminary and centre of our system. I kept my eye riveted upon that point of the disk where the eclipse was to commence, with an anxiety known only to astronomers; with the chronometer watch at my ear, I attended to the most doubtful appearances which my perturbation perhaps presented to the eye, and upon every alarm, began to count the beats of the watch (five in two seconds) in order that I might not lose the very first instant of the impression, and I am confident that not one quarter of a second was lost."
The last letter that has been preserved from the interesting correspondence between Dunbar and Jefferson, bears the date of Dec. 17, 1805. With it was enclosed Dunbar's "Method of finding the Longitude by a single observer without any knowledge of the precise time," a problem that had been solved by him at Jefferson's request. This formed an eleventh contribution to the publication referred to above.
There is no reason for doubting that this correspondence was continued throughout the remaining four years of Dunbar's life, though the letters have not been found by the writer.
Dunbar's last contribution to the Transactions was entitled: "Observations on the Comet of 1807-'8." It was read before the Society Nov. 18, 1808. In this article appears at least one entry which indicated that the scientific services of its author were drawing to a close. "Indisposition," says he at one point in the narrative, "prevented observation for some time past." A few months from this date the scientific investigation of this remarkable man were brought to a close.
Writers have frequently noted the fact that many great men have lived in advance of their times. To substantiate this assertion they cite us to the careers of Copernicus, Galileo, Newton, and a host of others. That Dunbar is entitled to the same distinction might be amply proved by a study of his life.
The most conclusive evidence of this fact is furnished by his idea of the relation the government should sustain to scientific explorations. In a letter to John Vaughan, bearing the date of March 21, 1802, he writes as follows:
"There is no example of any encouragement being held out by [our] Government; no spirit of inquiry set on foot at the public expense. What is the reason, we have no State observatory to which individuals might send their contributions & from which they might receive astronomical intelligence.... No naturalist travels at the public expense to explore our immense country & make us acquainted with the infinite resources it Contains upon its surface, in its waters & within its bowels, from whence great national advantages would result; the public & individuals would be instructed where to direct their researches after such objects as might become subjects of curiosity, Public the exercise of genius & agrandizem't of fortune; but it would seem that the speculations ... of our politicians are confined within the narrow circle of the Customs & Excise, while literature of our present illustrious President will correct & enlarge the views of our public men, & that under his auspices & protection, Arts, Science, & Literature may take a flight, which will at length carry them beyond those European brethren, as wel[l] to[o] as above them in the enjoyment of national liberty."