"Philadelphia, Pa., August 30, 1791.
"Sir,—I thank you sincerely for your letter of the 19th instant, and for the almanac it contained. Nobody wishes more than I do to see such proofs as you exhibit, that Nature has given to our black brethren talents equal to those of the other colors of men, and that the appearance of a want of them is owing only to the degraded condition of their existence both in Africa and America. I can add with truth that no one wishes more ardently to see a good system commenced for raising the condition both of their body and mind to what it ought to be, as fast as the imbecility of their present existence, and other circumstances which cannot be neglected, will admit. I have taken the liberty of sending your almanac to Monsieur de Condorcet, Secretary of the Academy of Sciences at Paris, and Member of the Philanthropic Society, because I considered it a document to which your whole color had a right for their justification against the doubts which have been entertained of them.
"I am, with great esteem, Sir,
"Your most obedient serv't,
"THO. JEFFERSON."
When his first almanac was published, Banneker was fifty-nine years of age, and had received tokens of respect from all the scientific men of the country. The commissioners appointed after the adoption of the Constitution in 1789 to run the lines of the District of Columbia invited the presence and assistance of Banneker, and treated him as an equal. They invited him to take a seat at their table; but he declined, and requested a separate table.
Banneker continued to calculate and publish almanacs until the year 1802. Besides numerous valuable astronomical and mathematical notes found amongst his papers are observations of passing events, showing that he had the mind of a philosopher. For instance:—
"27th Aug. 1797. Standing at my door, I heard the discharge of a gun, and in four or five seconds of time the small shot came rattling about me, one or two of which struck the house; which plainly demonstrates that the velocity of sound is greater than that of a cannon-bullet."
"23d Dec. 1790. About 3 o'clock A.M., I heard a sound and felt a shock like unto heavy thunder. I went out, but could not observe any cloud. I therefore conclude it must be a great earthquake in some part of the globe."
In April, 1800, he writes:—