Introduction to the primary source written by James G. Basker, from James G. Basker (editor) with Nicole Seary, Black Writers of the Founding Era: 1760–1800 (New York: Library of America, 2023), p. 362.
“Famous for the series of almanacs he compiled in the 1790s, Benjamin Banneker was the most accomplished African American astronomer and scientist in the early history of the United States. The child of a free Black mother and a formerly enslaved father from Africa, Banneker was an autodidact with limited schooling but a lifelong intellectual curiosity. In his fifties he took on astronomy and, with the support of members of the prominent Ellicott family, who lived near him in rural Maryland, he was appointed to the surveying team that laid out the District of Columbia in 1791 and he produced the almanacs that were published over several years in seven cities, from Baltimore and Philadelphia, to Richmond, Virginia.”
Sir,—I received your letter at the hand of Bell but found nothing strange to me. In the Letter Concerning the number of Eclipses, tho according to authors the Edge of the penumber only touches the Suns Limb in that Eclips, that I left out of the Number—which happens April 14th day, at 37 minutes past 7 o’clock in the morning, and is the first we shall have; but since you wrote to me, l drew in the Equations of the Node which will cause a small Solar Defe[c]t, but as I did not intend to publish, l was not so very peticular as I should have been, but was more intent upon the true method of projecting a Solar Eclips—It is an easy matter for us when a Diagram is laid down before us, to draw one in resemblance of it, but it is a hard matter for young Tyroes in Astronomy, when only the Elements for the projection is laid down before him to draw his Diagram with any degree of Certainty.
Says the Learned LEADBETTER, the projection, I shall here describe, is that mentioned by Mr. Flamsted. When the sun is in Cancer, Leo, Virgo, Libra, Scorpio or, Sagitary, the Axes of the Globe must lie to the right hand of the Axes of the Ecliptic, but when the sun is in Capricorn, Aquarius, Pisces, Aries, Taurus, or Gemini, then to the left.
Says the wise author FERGUSON, when the sun is in Capercorn, Aquarius, Pisces, Aries, Taurus, and Gemeni, the Northern half of the Earths Axes lies to the right hand of the Axes of the Ecliptic and to the left hand, whilst the Sun is on the other six signs.
Now Mr. Ellicott, two such learned gentlemen as the above mentioned, one in direct opposition to the other, stagnates young beginners, but I hope the stagnation will not be of long duration, for this I observe that Leadbetter counts the time on the path of Vertex 1. 2. 3 &c. from the right to the left hand or from the consequent to the antecedent,--But Ferguson on the path of Vertex counts the time 1. 2. 3 &c. from the left to the right hand, according to the order of numbers, so that that is regular, shall compensate for irregularity. Now sir if I can overcome this difficulty I doubt not being able to calculate a Common Almanac. —Sir no more
But remain your faithful friend,
B. Banneker.
Mr. George Ellicott, Oct. 13th, 1789
Source: “Letter to George Ellicott, October 13, 1789.” In J. Saurin Norris, A Sketch of the Life of Benjamin Banneker; From Notes Taken in 1836/ Read by J. Saurin Norris, before the Maryland Historical Society, October 15, 1854 (Baltimore: John D. Toy, 1854), pp. 8–9. In James G. Basker (editor) with Nicole Seary, Black Writers of the Founding Era: 1760–1800 (New York: Library of America, 2023), pp. 362–363.