John Isaac Hawkins

[3][4] John Isaac emigrated to the United States about 1790,[5] attending the College of New Jersey,[6] where he studied medicine and later, chemical filtration.

In his own account, he was influenced by work of Georg Moritz Lowitz to try charcoal for filtration purposes, and ran an exhibition on the topic, with Raphaelle and Rembrandt Peale, in the Philadelphia Exchange Coffee House.

[14] Hawkins and his wife adopted from the workhouse a child, James Chalmers, orphaned after his parents had entered the Poyais scam of Gregor MacGregor; he died young.

[16] Back in London, where his wife Anna died in 1838,[17] he superintended the construction of the Thames Tunnel under Isambard Kingdom Brunel.

[19][20][21] Later in life Hawkins fell into debt[18] and concluding that America presented a better opportunity to profit from his patents, he decided to re-emigrate, departing in autumn 1848.

Lectures there for local ladies could not survive their disapproval of his display of human skulls or the preserved organs of his deceased adopted son, his only child, whom he had dissected following the boy's death at age seven.

He was living in Philadelphia when he invented and first produced the pianino or cottage pianoforte – the "portable grand" as he then called it – which he patented in 1800.

The action, in metal supports, anticipated Robert Wornum's in the checking, and later ideas in a contrivance for repetition.