Heading: (Mathematics, 1848 - American ‘mental calculator’)
Author:
Title: Early American math genius, rare 1848 letter
Place Published:
Publisher:
Date Published: 1848
Description:

Peter M. Deshong, "Mathematician". Autograph Letter Signed. NY, March 7, 1848. 1pg.+ address leaf. To Connecticut Life Insurance Co., Hartford, Conn.

"Wishing to extend my new method of computing numbers among Merchants &; Bankers...I will give you a brief statement of the Mathematical powers I possess. First let a Ledger be opened and a column of figures be presented, I will give the sum total in 5 seconds...it matters not what the length or breadth of the column is...let a sum be written in multiplication with 1000 figures for the multiplier and as may for the multiplicand. I will...write the product underneath... as fast as figures can be written down...Fractions of every denomination can be summoned up instantly without reducing to a denominator. These Rules can be learned by any person...remitting me $2 through the N.York PO..." Peter Martin Deshong (1825?-1850) was one of the first American "mental calculators" or "calculating prodigies" who would compute large figures in his head faster than others could figure them on paper - and perhaps the very first to contend that he could teach others to emulate his abilities. This ran him afoul of the law in 1845, when he was arrested in Philadelphia for "swindling", selling, for $3 each, a set of written "rules" that one newspaper denounced as "fictitious and forged", this "pretended American Babbage...locomotive calculating machine" being a "gross imposter...[with] a poor education...shamefully ignorant [of]...the philosophy of arithmetic." He was acquitted of the charge, even critics admitting that he "certainly possess an extraordinary...faculty of calculation", perhaps "one of the greatest mathematical geniuses of his age", yet a "humbug" who was totally unable "to impart his skill to others." More generously, in 1847, the Scientific American praised his "wonderful powers" which have "astonished all those who have witnessed their exhibition", appearing at the Mount Washington Observatory to mentally calculate the trajectory of Halley 's Comet "faster than fifteen of the scientific gentlemen could do altogether." Two years after he wrote this letter, he died aboard a Canadian steamship, probably of a "severe" epileptic fit, Deshong 's letters are apparently very rare; WorldCat 's Archive Grid shows none of his correspondence held by any American institution.

Some edge coloration; very good