Monticello, too, he could gratify his delight in the natural
sciences, for he was a true child of the eighteenth century in
his insatiable curiosity about the physical universe and in his
desire to reduce that universe to an intelligible mechanism. He
was by instinct a rationalist and a foe to superstition in any
form, whether in science or religion. His indefatigable pen was
as ready to discuss vaccination and yellow fever with Dr.
Benjamin Rush as it was to exchange views with Dr. Priestley on
the ethics of Jesus.

The diversity of Jefferson's interests is truly remarkable.
Monticello is a monument to his almost Yankee-like ingenuity. He
writes to his friend Thomas Paine to assure him that the
semi-cylindrical form of roof after the De Lorme pattern, which
he proposes for his house, is entirely practicable, for he
himself had "used it at home for a dome, being 120 degrees of an
oblong octagon." He was characteristically American in his
receptivity to new ideas from any source. A chance item about Eli
Whitney of New Haven arrests his attention and forthwith he
writes to Madison recommending a "Mr. Whitney at Connecticut, a
mechanic of the first order of ingenuity, who invented the cotton
gin," and who has recently invented "molds and machines for
making all the pieces of his [musket] locks so exactly equal that
take one hundred locks to pieces and mingle their parts and the
hundred locks may be put together as well by taking the first
pieces which come to hand." To Robert Fulton, then laboring to
perfect his torpedoes and submarine, Jefferson wrote
encouragingly: "I have ever looked to the submarine boat as most
to be depended on for attaching them [i. e., torpedoes]....I am
in hopes it is not to be abandoned as impracticable."