The duplicating polygraph is a mechanical device used for reproducing images and handwriting. The device was most popular in the early 19th century, particularly in the hands of various American statesman. The mechanical logics for the device were based on the pantograph, a 17th century tool created for drafting and image reproduction.
The duplicating polygraph is not to be confused with the contemporary electric polygraph, or "lie detector".
From the Greek, polygraph literally means “many hands” or “many writings” (the suffix -graph implies not simply the hand, but that which is written with or by the hand). According to the Oxford English Dictionary, the earliest form of the word is adjectival and dates to the early 18th century, referring to a prolific individual or voluminous book. Instances of the word in the late 18th century refer to “a person who imitates or very closely resembles another; an imitator, an imitation.” Thus, the word (as both a noun, polygraph, and an adjective, polygraphic) initially implied a form of personal mimesis in which one individual adopts the social significations of another. Its usage as a noun in reference to the mechanical device is not recorded in the Oxford English Dictionary until 1803.
"Frame" and "Origins" of the Polygraph
The polygraph emerged in the late 18th century as merely one of a score of instruments designed and patented for the mechanical reproduction of handwriting. It burgeoned from a emerging anxiety regarding the ephemerality of print, as well an increasing socio-political desire to compile information for the benefit of posterity.
Late eighteenth and early nineteenth century inventors employed two methods for overcoming the singularity of handwriting:
1. transferring ink to another sheet of paper or tissue via applied pressure, as seen with James Watts' copying press patented in 1780
2. constructing a device to copy movement of the hand by using the hand itself as a motor, as seen with the pantograph and the polygraph
The copying press was wildly popular in the late 18th and 19th century, and was used by figures such as George Washington, Benjamin Franklin, and Thomas Jefferson (Bedini 10-3). The difficulty of the copying press, however, was that the inks used could only be transferred to tissues; it could not produce instantly duplicated letters, only referents of the original letter. The handwriting could be duplicated, but not the material letter itself.
Devices based on the geometry of the pantograph were initially used for the production and reproduction of drawings, landscapes and miniatures (Bedini 35). Pantographic mechanisms were employed in the service of writing as early as 1648 and throughout the 18th century, but these efforts were cumbersome and impractical. The French artist Cotteneuve produced a pantographic device in 1763, presenting it at the Royal Academy of Sciences, and called it a “polygraphe” or “copiste habile” (skillful copyist) (Bedini 38).
The first popularly used polygraph was developed by Marc Isambard Brunel, an architect and civil engineer from France who escaped to the United States and then settled in England. He was first granted an American patent in January 1799 for a “machine for writing with two pens” (the American patent was lost in the Great Patent Fire of 1836). Brunel's polygraph was a framework device that remediated the pantograph's parallelogram; the writer wields the pen on one side of the device and whatever is inscribed is reproduced by a jointed pen on the other side of the frame. On April 11, 1799, Brunel was granted a patent for the device in England, where it enjoyed some popularity. The patent abstract reads as follows:
Brunel 11th April 1799 2305. A grant unto MARC ISAMBARD BRUNEL, of the parish of St. Mary, Newington, in the county of Surry, gent, for his new invented writing and drawing machine, by which two or more writings or drawings resembling each other may be made by the same person at the same time; to hold to him, his exors, admors, and assigns, within England, Wales, and the town of Berwick-upon-Tweed for the term of fourteen years pursuant to the statute; with a clause to inroll the same within one calendar month from the date thereof. W.H.M. at Westm, the 11th day of April, in the year above (Woodcroft 424).
The significance of this invention is located in the notion of "by the same person at the same time." In the case of the polygraph, the moment of composition and the moment of reproduction are temporally condensed into the singular act of an individual's handwriting. The duplicating polygraph should be understood as symptomatic of a particular crisis of the sign in early modernity. As suggested by Jean Baudrillard, modernity is marked by a fracture between social signifiers and their signifieds (Crary 12). In the medieval period, the sign referred specifically to a particular position within a social order: "An interdiction protects the sign and assures them a total clarity; each sign refers unequivocally to a status" (qtd. in Crary 11-2). Alternatively, the mechanical and industrial reproduction inaugurated in early modernity divorces the signifier from the realm of handcraft, and in turn, from its discrete relationship to its signified. The mechanical duplication of signs allows for endless mimetic possibilities, and eventually renders an end to mimesis itself. The crisis of the signs in modernity is that signs, even reproduced, are no longer imitations, but duplications, marked by “equivalence and indifference” (qtd. in Crary 12).
The presence of the hand "at hand" in the polygraph is thus significant. The reproduction of the handwritten at the very moment of the writing itself provides an assurance against Baudrillard's signifiers of "indifference." The temporal suturing of writing, writer and reproduction guarantees a remainder of "essence" attached to the letter itself. In an early modernity under the thrust of a “proliferation of signs on demand”, the presence of handwriting becomes the last vestige of handcraft. Heidegger makes such a relationship explicit in his Parmenides lectures, in which he argues that the hand holds the “essence of man”:
"Man himself acts through the hand; for the hand is, together with the word, the essential distinction of man. Only a being which, like man, 'has' the word, can and must 'have' 'the hand.' Through the hand occur both prayer and murder, greeting and thanks, oath and signal, and also the 'work' of the hand, the 'hand-work,' and the tool. The handshake seals the covenant. The hand brings about the 'work' of destruction. The hand exists as hand only where there is disclosure and concealment. No animal has a hand, and hand never originates from a paw or a claw or a talon. [...] Man does not 'have' hands, but the hand holds the essence of man, because the word as the essential realm of the hand is the ground of the essence of man." (qtd. in Kittler 198)
For Heidegger, it is the typewriter that will later tear writing, and thus the essence of the human, from "the essential realm of the hand" (qtd. in Kittler 198). As an instrument that preserves the presence of the hand at the moment of reproduction, the polygraph assures equivalence without indifference, to turn Baudrillard's phrase back on himself. In this critical and historical context, the polygraph emerges as a medium straddling an anxious historical chasm between free-floating, mechanically-identical signifiers of sameness, and a socio-political desire to guarantee human presence at the moment of writing and reproduction.
Four years later, Brunel's polygraph received challenge from a similar device produced by Philadelphia inventor John Isaac Hawkins. Hawkins' machine was in principle similar to Brunel's machine, with the primary distinction being that the duplication occurred side-by-side in Hawkins device rather than across the frame of the polygraph. The production of the polygraph with done in collaboration with fellow Philadelphia inventor, Charles Willson Peale. Peale offered to prepare a preliminary patent application. At first uncertain about the originality of the invention, they finally determined that Hawkins invention differed significantly from Brunel's.
An American patent was granted May 17, 1803 for the “Improvement in the pentagraph and parallel ruler”. A British patent was granted in September 1803:
Hawkins 24th Sept. 1803 2735 A grant unto ISAAC HAWKINS, of Bordenton, in the Unites States of America, now residing in King Street, Clerkenwell, in the county of Middx, merchant, for his new invented machinery & methods for writing, painting, drawing, ruling lines, & other things, and for applying parts of the aforesaid machinery to other purposes; to hold to him, his exors, admors, and assigns, within England, Wales, & the town of Berwick-upon-Tweed for the term of fourteen years pursuant to the statute; with a clause to inroll the same within one calendar month from the date thereof. W.H.M. at Westminster, the 24th day of September, in the year above (Woodcroft 493).
An anonymous article published in Philadelphia's Salem Gazette in 1803 describes Hawkins' polygraph as a device which "multiplies copies of writing, or rather makes originals." Again, the significance of the device lies in its ability to make multiple originals, rather than imitations or referents of the original.
Thomas Jefferson and the Polygraph
On five months full tryal of the Polygraph with two pens, I can now conscientiously declare it a most precious invention. Its superiority over the copying press is so decided that I have entirely laid that aside; I only regret that it had not been invented 30 years sooner, as it would have enabled me to preserve copies of my letters during the war, which to me would have been a consoling possession.
- Letter from Thomas Jefferson to Charles Willson Peale, August 19, 1804. Later republished as an endorsement in an advertisement for the Polygraph in Poulson’s Daily American Advertiser on December 6, 1804.
Thomas Jefferson is perhaps the polygraph’s most famed user and his advice to Charles Willson Peale, the developer of the device in the United States, had a direct impact on the refinement and advancement of the polygraph. This section will elaborate why Jefferson found the polygraph so appealing in his work, the implications of duplication for the maintenance of a government record, and his correspondence with Peale regarding improvements to the machine.
Writing letters was an intense preoccupation for Jefferson, an activity that took up half his day and culminated into the production of close to 20,000 letters. 1 He kept the duplicates of these letters, produced by the polygraph, in filing presses, which were organized alphabetically and chronologically in his personal archive in Monticello. 2 His meticulous attention to record keeping has been accredited by some to two experiences in which all of his books and papers were lost. The first was an incident on February 1, 1770, where his family home in Shadwell was burnt to the ground with all of possessions. The second, in 1780, when Benedict Arnold’s raid on Richmond destroyed much of Virginia’s records, which included Jefferson’s personal and public papers (Bedini 1).
Jefferson also had less personal reasons to maintain records of his correspondence. Involved with the creation of the United States during its early, formative period, records were also a means to establish a heritage for a nation with an emerging identity. Jay Fliegelman, in his book Declaring Independence: Jefferson, Natural Language, and the Culture of Performance, argues that the importance of persuasive rhetoric in the United States was especially key in this period, where the orator was to convince the listener not only through coherence but through the usage of expressive emotion. Fliegelman sees this as the origin of a distinct form of independent selfhood, where all expression is a form of self-expression, and takes Jefferson as a primary figure within this rhetorical shift (Fliegelman 2).
One could perhaps extrapolate from this argument that Jefferson was also interested in giving an expressive voice to the new republic through the formation of a record. Cornelia Vismann in Files: Law and Media Technology would not doubt concur: in her discussion of the modernization of Prussia in the early 1800s, she argues that, “By anticipating how it will be viewed by future history, the state becomes a subject of history. Archiving its files amounts to the administration of an estate on a state level...Administrative acts reveal themselves to be historical anticipations” (Vismann 120). Similarly, the United States was developing its identity in Jefferson’s time with an attention towards future historical importance, thus the formation of an archive was closely aligned with the United States as a “subject of history” in Vismann’s terms. The production of documentation and correspondence increased as part of this project, necessitating copy devices. For statesmen, such as Jefferson, the polygraph in particular facilitated copied letters which maintained the imprint of handwriting and the paper weight of the original letter, yielding an air of authority and authenticity. (Stakes that were especially crucial during this period, see Polygraphs Proper 3) Under these circumstances, Jefferson recommended the polygraph heartily to many of his colleagues in government and to governmental representatives from other nations. In the year 1804, chief clerk of the Department of State Jacob Wagner and professional surveyor Isaac Briggs purchased polygraphs on the recommendation of Jefferson (Bedini 87), and Jefferson gave the polygraph as a gift to the Tunisian ambassador Siddi Suliman Mella Menni (Bedini 134) as well as Commodore Edward Preble of Sicily (Bedini 117).
Jefferson first encountered the polygraph through friend, engineer and architect Benjamin Henry Latrobe. Latrobe demonstrated the device to him in 1804 and Jefferson asked to borrow it. Latrobe then ordered one for Jefferson, and Peale decided to present the polygraph as a gift to the president. Peale was to continue to develop customized polygraphs after this initial gift, according to Jefferson’s requests, recommendations and feedback. Jefferson took on an almost informal advisory role in the development of the device, addressing some of the design flaws of the original. Jefferson’s first observation was that the wooden writing surface would become warped over time, and suggested an alternate placement of the wood akin to that of parquet floors (which he had recently installed in his house) that would prevent movement of the wood slab (Bedini 71). Peale considered his idea, until he realized that the warping of the wood was the result of inaccurately drilled holes, which he remedied by improving the drills.
In April, May and August of 1804, Peale was to produce three additional customized polygraphs for the president, according to his specifications. The first, a portable version, had a removable cover, instead of folding up into the appliance, and ink holders at each end, to provide for more ink, both Jefferson’s ideas (Bedini 73). The second was a stationary model, which doubled as a writing desk. Jefferson suggested an extra screw be added to the copying pen, so that it could be adjusted. Peale also added new alterations on his own, providing a lighter pen bar as well as a stay for the pen bar, which was a new modification recently introduced by Hawkins (Bedini 77). The third version was to be a replica of the second, intended for use in Monticello. Jefferson also requested that the inkholders be moved higher and placed in a tray, and the desk portion was to be shallower in this third model (Bedini 80). Both the portable and stationary models were elaborated through an ongoing discussion about the instrument between Peale and Jefferson. Jefferson, in later correspondence with Peale, was also responsible for introducing new inkpots, which were more convenient in shape and size (Bedini 81). Jefferson also complained about the fragility of the pens, an observation that lead Peale to modify their design, making them wider above the point and increasing their concavity to hold more ink. (Bedini, 83)
If Jefferson built up his archive to create a record for the United States as a nation, he succeeded in doing so in large part due to the polygraph. The copies of his correspondence produced through the copying press, from 1785 to the beginning of 1804, used less durable paper and ink, and his letters preserved through this method are now, to a great extent, illegible. (Bedini 204) Letters produced via the polygraph, however, have held up to the pressures of wear and time, and still remain legible today. (Bedini 204) In its ability to produce a longstanding record, Jefferson's "most precious invention", the polygraph, was indeed superior to the copying press.
Advertisement and Reception in America
Despite the enthusiasm of Jefferson and Latrobe, and Peale’s citation of their praises in a host of printed advertisements from 1804 to 1806, the polygraph largely failed to capture the American imagination. While Hawkins sold all of the 150 polygraphs manufactured in England, Peale sold approximately 60 of the 80 polygraphs he produced in the U.S. (Bedini 187). In 1807, advertisements for two-pen polygraphs patented by P.A. Meiser and E. Seargeant appeared in newspapers along the Eastern seaboard. Meiser and Seargeant also advertised "A Polygraphic Book Machine," or a mechanism which allows letters to be copied into a book through carbon copy: the less-expensive method that would surpass the polygraph in popularity, especially when combined with the typewriter. Peale retired in 1810, and by 1809, polygraphs are mentioned in print only as items for sale at auction or in estate sales.
Looking at newspapers from the Early Republic, this section will address the problem of selling the polygraph to the American public. While the polygraph failed to become a technology of litigation, administration or mercantile operation, it spoke to fundamental issues of authenticity and authorship that arose in the 19th Century when, as Jonathan Crary describes (evoking Heidegger), “new technologies and forms of exchange put in question notions of the ‘hand’” (Crary 22).
The hands of good men
As he readied his first polygraphs for sale in America, Peale expressed anxiety over the masses getting a hold of his meticulously constructed machines. “Write to me whether you think anything more is necessary to be done, before we send this the Polygraph into the world amongst fools & knaves,” he asked Latrobe in 1803, “yet I most certainly prefer their falling into the hands of good men as I wish to work only for such” (Bedini 56). While a major selling point of the polygraph was that it saved labor, its manufacture was relatively labor-intensive. As Peale outlines in his first advertisement, published in Poulson's American Daily Advertiser on October 3, 1803:
Every invention that saves labour and time merits attention and approbation of the inhabitants of America [...] My desire to promote the manufactory of an invention which promises to become to generally useful, prompts me to superintend a work of machinery to perform several similar movements, which I know must be executed with great accuracy, otherwise the best of intentions might be destroyed or lost to the public, wherefore I have spared neither labour or expense to simplify the machinery (qtd. in Bedini 52-53).
Peale employed two cabinet makers to build the machines. While the well-built, carefully tested polygraph was easy to use, because of its meticulous construction, it was not so easy to fix. Heavily invested in their performance, Peale was often on call to fix and improve the machines. The reputation of a burgeoning technology was at stake, and, akin to the signature or the spoken guarantee, Peale's commitment to servicing the machines attached a certain ethos to commerce: "I most certainly prefer their falling into the hands of good men as I wish to work only for such".
It is no surprise, therefore, that Peale "signed" all of his advertisements by printing his name in italicized letters above or below. It is also telling that signature machines - which conserve both labor and authenticity - are the primary remediation of the polygraph (Bedini 199).
In addition to values accorded to labor and authenticity, price also shaped the polygraph market. Polygraphs were a considerable investment: Peale asked $50 for the two pen model, and $60 for three pens - approximately $955 and $1145 today.  The machine was thus lodged in an elite network shaped by literacy and affluence, a network it reinforced by preserving rather disseminating information. The polygraph "is used only by a few litterary [sic] men, who will take pains to save themselves troubles," Latrobe observed in a letter to Jefferson in 1817 (qtd. in Bedini 173). Of the sixty polygraphs sold in the U.S., Latrobe reported, close to forty were sold by his personal recommendation.
As the revenue necessary to support the production of polygraphs failed to materialize, Peale endeavored to extend his business based on the model of handwritten correspondence to a more public market through print ads and demonstrations - to little avail. An advertisement placed by Peale's son Rembrant in the Baltimore Federal Gazette on June 15, 1804 presages Latrobe's observation of polygraphs and "litterary men" (qtd. in Bedini 81-82):
On Writing With Messrs. Peales’ Polygraphs
Twin offspring of th’inventive mind, / Of Hawkins and Peale combin’d, / The first conceiv’d th’ingenious thought, / The last the high perfection wrought; / Pois’d by the spiral chord above, / The obedient pens in concert move. / Triumph of art! amaz’d I view, / A transcript fair of all I drew: / So morning show’rs, and ev’ning dews, / In swelling germs new life infuse, / but if no genial warmth supply, / The verdant buds, inert they lie, / Till rous’d by Sol, and zephyr bland, / The leaves unfold and flowers expand. / Cowper.
Here Rembrant writes in the characteristic lyrical style of the then recently deceased English poet William Cowper, and "signs" the advertisement with the poet's name. It is striking (and indicative of the polygraph's historical moment) that while Rembrant sings the praises of mechanically duplicating hand wrought expression - "The obedient pens in concert move. / Triumph of art! amaz'd I view" - his tactical mimicry hinges on the catoptric, generic nature of type.
Despite his son's poetic enterprise and his own sustained efforts to utilize print advertisement, Peale wrote to Hawkins in 1807, “I cannot make an impression on the public mind to produce a demand for Polygraphs, yet those who look at them always speak with admiration of the ingenious contrivance” (qtd. in Bedini 152). The need to "look at" the polygraph - to see it in person - highlights the difficulty of generating public appeal. Newspapers represented a convenient public forum, but, at this time, had no images. In print, the "ingenious contrivance" was typographically flattened beside ads for salt, the Albion Benevolent Society, a runaway slave named Jim, and patent antiseptic (American Citizen, New York, July 14, 1804).
Actions and words
The polygraph is a machine that shows its user how it works. As an article announcing the sale of polygraphs in 1803 describes, the polygraph “is so simple in the construction of its machinery that the movement is perfectly easy; not liable to get out of order; and the knowledge of using it obtained in one minute” (Salem Gazette, Massachusetts, Sept. 5, 1803). Though it has many parts and, as the back and forth between Peale and Jefferson suggests, could be endlessly tinkered with, the polygraph’s general mechanism is relatively obvious and simple to operate. Sitting down to write, the two pens, aligned side by side, are the immediate focus: grip one and begin to write, and the other moves right beside one’s original inscription. The device that joins the two pens moves visibly behind the guillotine, connected with the action of writing. Unlike print duplication, the hand plugs directly into and participates as a part of the copying machine. In Techniques of the Observer, Crary observes that “[b]eginning in the nineteenth century, the relation between eye and optical apparatus becomes one of metonymy: both were now operating on the same plane of operation” (Crary 129). As a mechanical extension of handwriting (occupying the interval between the copying press and the typewriter), the polygraph engendered a similarly metonymic relationship between the hand, the inscription, and the copy.
Demonstration was thus an ideal way to introduce the polygraph. The machines were permanently on view at Peale’s museum in Philadelphia (in a room that also housed a mastodon skeleton), and he periodically distributed handbills to the public to come and take a look. Vice President Aaron Burr visited the museum in January of 1804 and purchased a polygraph on the spot (Bedini 59). To prospective buyers further a field, Peale sent copies of letters, noting that they had been written with the polygraph (Bedini 59). These letters were the “hello world” communiqués of handwritten duplications.
In July 1804, Peale traveled to New York City to demonstrate the polygraph at the Tontine Coffee House for two weeks. He was sure to place announcements in several New York papers, that, as David Henkin writes in his book City Reading: Written Words and Public Spaces in Antebellum New York, “functioned as sites of public opinion and critical discussion of public affairs” at the turn of the nineteenth century. These papers “evoked broad networks of international shipping and commerce and reproduced a mode of discourse associated with the salon,” and the Tontine was “the symbolic center of this world” (Henkin 123). Thus the public space in which Peale chose to demonstrate the polygraph was more accurately a public sphere: an imagined community that corresponded to a certain vision of the polygraph’s market (Henkin 123).
The polygraph caught the attention of Tontine patrons, who, in the spirit of public debate, by turns marveled at the machine and dismissed it, contesting that they had seen the same technology in France - most likely referring to Brunel's earlier model (Bedini 85-86). When the crowd became too loud, Peale expressed himself by scribbling away with the polygraph. “I very frequently wrote answers to what they were saying—that had no bad effect I could rub those kind of grumbling geniuses pretty hardly without seeming to pay attention to what was said," Peale remarked in his diary, "and all the by standers were continually reading what I wrote” (qtd. in Bedini 86). Peale thus answered the skeptical crowd by performing the functionality of the medium: producing a handwritten copy simultaneously with the original.
Peale sold one polygraph during his week-long demonstration at the Tontine, to the diplomat John Armstrong (Bedini 86). This sale, along with continued support from the recently re-elected Jefferson, encouraged Peale to promote polygraphs to government offices. Peale traveled to Washington in December of 1804, and demonstrated the machine to members of Congress. While the statesmen admired the contrivance, Peale sold no polygraphs during his two-week stay (Bedini 101).
Interestingly, Peale’s final announcement for his demonstration at the Tontine Coffee House on July 14th was printed next to death notice for the statesman Alexander Hamilton on the front pages of the New-York Gazette and the Republican Watch-Tower. Hamilton had been shot two days prior, in a duel with Aaron Burr - the former vice president who bought a polygraph in early 1804. Burr had recently campaigned for governor of New York. During Burr’s unsuccessful run, Hamilton – a political rival – had joined the chorus of insults published in Federalist papers. What ultimately sparked Burr's challenge to Hamilton was a letter written by Charles D. Cooper published in the Albany Evening-Post, which described Hamilton calling Burr "despicable" at a dinner party (Fleming 231).
Several days after Hamilton’s death, the Republican Watch-Tower publicized the controversy between the two statesmen by printing their private correspondence. This posthumous exposé was not surprising: the publication of Cooper's letter had sparked the duel, and the prospect of publicity strained the communication leading up to it. As historian Thomas Fleming writes, Hamilton "had no doubt that if he wrote a humble apology to Burr, it would appear in the Morning Chronicle the next day" (Fleming 288).
The following was printed in the Republican Watch-Tower on July 16, 1804: TO THE AMERICAN PUBLIC: The authenticity of the documents and the accuracy of the information which we have at last obtained, are beyond any question; and must put an end to all mistake or misrepresentation…The following is the correspondence that passed between General Hamilton and Colonel Burr, together with the conduct, motives and views of General Hamilton, written in his own hand.
The Watch-Tower even reproduced Hamilton’s will: “In testimony whereof, I have hereto subscribed my hand.”
The anxieties of libel and slander and the discourse of authenticity that surround the duel is marked by the specter of “the hand” - crucial to this spectacle of man-to-man confrontation, but necessarily excluded from print. As the shared space of the July 14th front page suggests, this discourse also surrounds the polygraph: a technology that, for a moment, established an equivalence between "the essential realm of the hand," to recall Heidegger's words, and mechanical reproduction.
American Citizen, New York, July 6 and July 14, 1804.
Bedini, Silvio A. Thomas Jefferson and His Copying Machines. Charlottesville: University Press of Virginia, 1984.
Crary, Jonathan. Techniques of the Observer: On Vision and Modernity in the Nineteenth Century. Cambridge: MIT Press, 1990.
Federal Gazette, Baltimore, June 15, 1804.
Fleming, Thomas. Duel: Alexander Hamilton, Aaron Burr and the Future of America. New York: Basic Books, 1999.
Fliegelman, Jay. Declaring Independence: Jefferson, Natural Language, and the Culture of Performance. Stanford: Stanford University Press, 1993.
Henkin, David M. City Reading: Written Words and Public Spaces in Antebellum New York. New York: Columbia University Press, 1998.
Kittler, Friedrich. Gramophone, Film, Typewriter. Trans. Winthrop-Young, Geoffrey and Michael Wutz. Stanford: Stanford UP, 1992.
Poulson's American Daily Advertiser, Philadelphia, October 3, 1803 and July 10, 1805.
Republican Watch-Tower, New York, July 16, 1804.
Salem Gazette, Massachusetts, September 5, 1803.
Vismann, Cornelia. Files: Law and Media Technology. Stanford: Stanford University Press, 2008.
Woodcroft, Bennet. Titles of Patents of Invention: Chronologically Arranged From March 2, 1617 (14 James I.) to October 1, 1852 (16 Victoria). London: 1854.