Mesne assignment

The term mesne assignment or mesne assignments appears on US patents in the early aero period. It is used as a legal label for the transfer, meaning sale, not just licensing of, patent rights. Assignees may be companies, or individuals, in rare instances one inventor, filing in collaboration with others, assigning his rights to the other(s). This or these cases may not be of the mesne variety. Some data associated with this overwhelmingly and specifically American legal designation will bear legitimate analogy to some data associated with phenomena of legal successor. We have heard of one instance of an American using specific assignment phraseology, on a British patent.

The normal term is simply "assignment" to describe such transfers or sales.

"Mesne" is a legal term, meaning intermediate, used to describe intermediate phenomena such as the temporary possession of land. It is not clear what it means in the patent context, or why it would be necessary or clarifying to use it in regard to a single transaction to transfer rights to a patent.

Thus, we have clear indication that direct assignment is seen in contrast to mesne, though we have cases of "direct and mesne assignment" being declared concurrently. The "direct" seems to be the implied default, only mentioned in the relatively rare cases in which both types of assignment are declared.

Three law dictionaries indicate that the term mesne in a property assignment does mean there is an intermediate third party who holds temporary ownership between the selling party and the buying party. Maybe that intermediate third party is the USPO, here?

In Scandinavian countries, the patent office tracks ownership of patents in a register -- it's a property right they can track and report -- so the proposition that the intermediary is the patent office would not be absurd, but I don't see that explicitly stated anywhere.

Worth checking: Are there assignments of US patent rights in our early aero period that do not use this "mesne" term? What characteristics differentiate the ones that do from the ones that don't?

• Do all assigned US patents in our period use this term "mesne"? We can do a little empirical research with just a list of specific patent documents that have assignments, and whether they say "mesne"
  • Indeed, not all patents documenting the assigning of rights use the term "mesne". Those using the language of assignment, without characterizing the assignment in any way, seem to be implying that the rights are assigned directly. Cases such as Patent US-1909-982079 have rights being assigned by both direct and mesne assignment.AvionHerbert (talk) 19:10, 19 August 2025 (PDT)
• Do the ones using "mesne" always have a patent agent? Maybe the patent agent is the implied intermediary.

Some small findings

• a present-day assignment of US patent rights is or requires a contract, per [1] and [2] That may have applied back in the time of early aero; or maybe it's just stated in a patent application or subsequent filing.
• a present-day assignment of US patent rights must be recorded at the USPTO to be properly binding, according to [3]. That seems likely to have been the case at the time of early aero.
• The comment about this 1933 patent suggests that "mesne" means someone else owned the patent between the inventor and the assignee, and that this was unusual and mysterious. [4]
• "Mesne" no longer appears in basic descriptions of US patent assignment (e.g. [5])
• There may have been a specific legal reform that obsoleted the use of this phrase. We might be able to narrow down when that happened and what the reform was. The links above show that the term definitely appears as late as 1933.
• A search for "mesne" in google patents finds that the term was used a lot until about 1970. It's occasionally used at least 1996, but those seem to be mainly references to earlier patents or mistranscriptions, e.g. of "means". Examples: [6], [7], an Australian example, [8], [9]. Conclusion so far -- some unidentified reform as of about 1970 makes the term nearly disappear from US patent applications since then.
• Ah!! A Patent Cooperation Treaty was signed or took effect just about 1970. https://ladas.com/education-center/a-brief-history-of-the-patent-law-of-the-united-states-2/ maybe that's the source of the change.

Request to USPTO for information

• There is a place to write for information about US patent assignments. I think it's mainly where one reports the sale or licensing of a patent, which USPTO must be tracking. They might know the answer to this, so I wrote them at AssignmentCenter@uspto. I asked in part: “Mesne” suggests there was an intermediary between the assignor and the assignee. Perhaps that was the patent office? If so, does that mean the patent office did more than register the event of the assignment? I just would like to understand what the phrase “mesne assignments” meant. There may be some significant reason they didn’t just print that party A assigned the patent to party B.
• I included two slightly different examples of how the term appears on patent specifications, on patents 1494787 and 1228281. The first says “by mesne assignments”. The second one says “by direct and mesne assignments”, as if there were two ways or types of mechisms to assign. ‘Direct’ suggests that there was no intermediary. Are these terms defined and contrasted in any public document? More examples: US patents 974961 and 1445135 have “mesne” alone, and 982079 and 1172196 have “direct and mesne”.

More sources yet

• Atty Tracey Roberts points me to a literature about patent intermediaries, who enabled matchmaking and eased licensing. The word "mesne" does not appear in these works. But it is perhaps normal that patent rights are passed from an owner (the inventor) to an intermediary that can handle the licensing process if there are many potential licensees; and the intermediary might also monitor and enforce the owner’s rights after assignment Intermediaries might also abuse that role and examples are discussed. [10] [11]
• The above-cited work by Mario Benassi & Miryam Martin-Sanchez has a helpful bibliography. Following it up I found other relevant works. Let's incorporate these works into this database, apart from whether they clarify the use of mesne on early aero patents.

Works cited by those works

• Intermediaries in the Market for Technology, 2011, by Naomi R. Lamoreaux, Kenneth L. Sokoloff, and Dhanoos Sutthiphisal, https://law.yale.edu/sites/default/files/area/workshop/leo/document/LEO11_Lamoreaux.pdf, full text available
• Pretel, D. (2018). The Global Rise of Patent Expertise During the Late Nineteenth Century. In: Pretel, D., Camprubí, L. (eds) Technology and Globalisation. Palgrave Studies in Economic History. Palgrave Macmillan, Cham. https://doi.org/10.1007/978-3-319-75450-5_6 (The Global Rise of Patent Expertise During the Late Nineteenth Century, Chapter, First Online: 14 June 2018, pp 129–157, Technology and Globalisation, by David Pretel, Part of the book series: Palgrave Studies in Economic History ((PEHS)), https://link.springer.com/chapter/10.1007/978-3-319-75450-5_6) full text not available yet

• Andersson, D. E., & La Mela, M. (2020). Nordic networks: Patent agents and the business of technology intermediation in Sweden and Finland, 1860–1910. Scandinavian Economic History Review, 68(1), 45–65. https://doi.org/10.1080/03585522.2019.1667425
• Andersson, D. E., & Tell, F. (2016). Patent agencies and the emerging market for patenting services in Sweden, 1885–1914. Entreprises et Histoire, 82(1), 11–31. https://www.cairn-int.info/load_pdf.php?ID_ARTICLE=E_EH_082_0011
• Inkster, I. (2012). History of technology (Vol. 31). Bloomsbury Academic.
• Lamoreaux, N. R., & Sokoloff, K. L. (1999). Inventors, firms, and the market for Technology in the Late Nineteenth and Early Twentieth Centuries. In N. R. Lamoreaux, D. M. G. Raff, & P. Temin (Eds.), Learning by doing in markets, firms, and countries (pp. 19–60). University of Chicago Press. http://www.nber.org/chapters/c10229
• Lamoreaux, N. R., & Sokoloff, K. L. (2001). Market trade in patents and the rise of a class of specialized inventors in the 19th-century United States. American Economic Review, 91(2), 39–44. https://doi.org/10.1257/aer.91.2.39
• Lamoreaux, N. R., Sokoloff, K. L., & Sutthiphisal, D. (2011). Intermediaries in the market for technology. https://law.yale.edu/sites/default/files/area/workshop/leo/document/LEO11_Lamoreaux.pdf.
• Love, B. J., Richardson, K., Oliver, E., & Costa, M. (2018). An empirical look at the “brokered” market for patents. SSRN Electronic Journal, 83(2). https://doi.org/10.2139/ssrn.3056444
• Monk, A. H. B. (2009). The emerging market for intellectual property: Drivers, restrainers, and implications. Journal of Economic Geography, 9(4), 469–491. https://doi.org/10.1093/jeg/lbp003
• Mossoff, A. (2013). The history of patent licensing and secondary markets in patents: An antidote to false rhetoric – Center for intellectual property x innovation policy. https://cip2.gmu.edu/2013/12/09/the-history-of-patent-licensing-and-secondary-markets-in-patents-an-antidote-to-false-rhetoric/
• Nicholas, T., & Shimizu, H. (2013). Intermediary functions and the market for innovation in Meiji and Taishō Japan. Business History Review, 87(1), 121–149. https://doi.org/10.1017/S0007680513000160
• Perrot, A., & Yvrande-Billon, A. (2014). Microeconomic foundations of patent markets: The role of intermediaries, auctions and centralized. In T. Madiès, D. Guellec, & J. Prager (Eds.), Patent Markets in the Global Knowledge Economy: Theory, empirics and public policy implications (pp. 55–74). Cambridge University Press. https://doi.org/10.1017/CBO9781107110960
• Pretel, D. (2018). The global rise of patent expertise during the late nineteenth century. In D. Pretel & L. Camprubí (Eds.), Technology and globalisation: Networks of experts in world history (pp. 129–157). Springer International Publishing. https://doi.org/10.1007/978-3-319-75450-5_6
• Reiffenstein, T. (2009). Specialization, centralization, and the distribution of patent intermediaries in the USA and Japan. Regional Studies, 43(4), 571–588. https://doi.org/10.1080/00343400701874255
• Wang, A. W. (2010). Rise of patent intermediaries. Berkeley Technology Law Journal, 25(1), 159–200. https://www.jstor.org/stable/24118623

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• Nicholas T. and Shimizu, H.: ‘Intermediary Functions and the Market for Innovation in Meiji and Taisho Japan’, Business History Review, Vol. 87, No.1 (2013), pp. 121–149. For Australia see Hack, B.: A History of the Patent Profession in Colonial Australia, Melbourne: Clement Hack & Co., 1984.
• On the writing of patent specifications see, for example, Myers, G.: ‘From Discovery to Invention: The Writing and Rewriting of Two Patents’, Social Studies of Science, Vol. 25, No. 1 (1995), pp. 57–105.
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• Bowker, G.: ‘What’s in a Patent?’, in Bijker, Wiebe E. and Law, John (eds.): Shaping Technology Building Society. Studies in Sociotechnical Change, Cambridge: MIT Press, 1992, pp. 53–75.
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• Lucier, P.: ‘Court and Controversy: Patenting Science in the Nineteenth Century’, The British Journal for the History of Science, Vol. 29, No. 2 (1996), pp. 139–154.
• MacLeod, C.: ‘The Paradoxes of Patenting: Invention and Its Diffusion in 18th- and 19th-Century Britain, France, and North America’, Technology and Culture, Vol. 32, No. 4 (1991), pp. 885–910.
• Lamoreaux, N. R. and Sokoloff, K. L.: ‘Intermediaries in the US Market for Technology, 1870–1920’ in Engerman S. L. et al. (eds.): Finance, Intermediaries, and Economic Development, Cambridge: Cambridge University Press, 2003, pp., 209–46
• Pretel, D. and Sáiz, P.: ‘Patent Agents in the European Periphery: Spain, 1826–1902’, History of Technology Vol 31, 2012, pp. 97–114.
• For the French case, in 1881, 89 percent of “cabinets” of Patent Agents were established in Paris. Gálvez-Behar, Des Médiateurs; In Britain in 1893, 53 percent of agencies were located in London. Inkster, Patent Agency.
• Khan, Z.: The Democratization of Invention: Patents and Copyrights in American Economic Development, 1790–1920, Cambridge: Cambridge University Press, 2005.
• Pretel and Sáiz, Patent Agents.
• The Artisan, The Repertory of Patent Inventors and Mechanics’ Magazine (in Britain)
• The American Artisan, American Inventor and the Patent Right Gazette
• Le Journal des Inventeurs and Moniteur des Inventions in France.
• Munn & Co., Hints to Inventors, New York: Munn & Co., 1867
• Johnson, J. and Johnson, J. H.: The Patentee’s Manual, London: Longmans, Green, and Co., 1890
• Thompson, W.P.: The Patent Road to Fortune, London: Stevens & Sons, 1884
• Thirion, C.: Législations Française et Étrangères sur les Brevets d’Invention: Tableau Synoptique, Paris: Dupont, 1878
• Carpmael, A.: Patent Laws of the World, London: W. Clowes, 1889
• Edwards E. and Edwards, A. E.: How to Take Out Patents in England and Abroad, London: Edwards and Co., 1905.
• Armengaud, J. E.: The Practical Draughtsman’s. Book of Industrial Design, London: Longman, Brown, Green and Longmans, 1853. The original in French is Cours de Dessin Linéaire Appliqué au Dessin des Machines, Paris: Z. Mathias, 1840.
• Machlup, F. and Penrose, E.: ‘The Patent Controversy in the Nineteenth Century’, The Journal of Economic History, Vol.10, No.1 (1950), pp. 1–29; Plasseraud, Y. and Savignon, F.: Paris 1883: Genèse du droit de brevets, Paris: Litec, 1983, pp. 102–6; Christine MacLeod, C.: ‘Concepts of Invention and the Patent Controversy in Victorian Britain’ in Fox, R. (ed.): Technological Change: Methods and Themes in the History of Technology, Amsterdam: Harwood Academic, 1996, pp. 137–153.
• Sir Williams Thomson to Dr. Bryce, ‘Discussion on Patents’, Glasgow Philosophical Society (14 December 1869), cited in Smith C. and Wise, M. N.: Energy and Empire: A Biographical Study of Lord Kelvin, Cambridge: Cambridge University Press, 1989, p. 708.
• ‘Inaugural Meeting’, Transactions of the Institute of Patent Agents, Vol. I, 1882–3, p. 46
• Imray, O.: ‘On Foreign Patents’, Transactions of the Institute of Patent Agents, Vol. II, 1883–4.
• May, C. and Shell, S.: Intellectual Property Rights: A Critical History, London: Lynne Rienner Publishers, 2006, pp. 115–117.
• British patent barrister Thomas Webster, a delegate at this conference, wrote about this meeting. Webster, T.: Congrès International des Brevets d’Invention tenu à l’Exposition Universelle de Vienne en 1873, Paris: Marchal, Billard et Cie, 1877.
• Ricketson, S.: The Paris Convention for the Protection of Industrial Property: A Commentary, Oxford: Oxford University Press, 2015, pp. 36–39
• Seckelmann, M.: ‘The Indebtedness to the Inventive Genius: Global Expositions and the Development of an International Patent Protection’, in Barth, V. (ed.): Identity and Universality / Identité et universalité, Paris: Bureau International des Expositions, 2002, p. 132
• Congrès international de la propriété industrielle tenu à Paris du 5 au 17 septembre 1878, Paris: Imprimerie Nationale, 1879.
• Penrose, E.: The Economics of the International Patent System, Baltimore: Johns Hopkins Press, 1951
• Plasseraud and Savignon, Paris 1883, pp. 155–174
• Gálvez-Behar, G.: La République des Inventeurs: Propriété et Organisation De l’Innovation en France, 1791–1922, Rennes: Presses Universitaires de Rennes, 2008, pp. 153–177.
• http://www.wipo.int/treaties/en/ip/paris/
• Penrose, The Economics of the International Patent System, Chapter 4
• Plasseraud and Savignon, Paris 1883, pp. 205–9
• Ricketson, The Paris Convention, pp. 69, 75–6.
• Max Georgii, founding member of this association, Georgii, M.: ‘International Association for the Protection of Industrial Property’, The Inventive Age, No.3 (March 1898), pp. 42–3.
• Annuaires de L’Association Internationale pour la Protection de la Proprieté Industrielle published from 1897; Annuaire de L’Association Internationale pour la Protection de la Proprieté Industrielle, 1902, Congrès de Turin, Paris, 1903, p. 31.
• ‘Professional Co-operation’, Journal of the Society of Patent Agents, Vol. II, No. 13 (January 1901), p. 1.
• For a detailed study of the CIPA in the late nineteenth century see Guagnini, ‘Patent Agents in Britain’.
• Paper read at the Eighth Annual Meeting of the Institute, Howgrave Graham, H.: On the Progress and Work of the Institute of Patent Agents, London: Spottiswoode & Co., 1890.
• Pretel's work [12] gives us this helpful statement and source about patent agents: "According to Ian Inkster, in the International Directory of Patent Agents for the year 1893, 2202 agencies were listed: 45% of them in the USA, 27% in France and 13% in Britain. Inkster, I.: ‘Engineers as patentees and the cultures of invention 1830–1914 and beyond: The evidence from the patent data’, Quaderns D’Historia de L’Enginyeria, Vol. VI (2004), pp. 25–50." Citing this potentially superb source: International Directory of Patent Agents, London: William Reeves, 1893, 1897 and 1901.
• Pretel has a helpful paper about the growth in the international agencies and directory at https://www.econsoc.hist.cam.ac.uk/docs/CWPESHnumber31Jan2018.pdf. It states: "International networks of agents grew rapidly during the 1890s. One indicator of this trend was the number of agents registered in the International Directory of Patent Agents, published in London from 1893. This directory ... provided information about agents’ locations and in some cases their credentials, services, costs, educational backgrounds and memberships in professional bodies. The number of agents registered in this directory increased from about 2,200 in 1893 to more than 4,000 in 1901." Source: The global rise of patent expertise in the late nineteenth century, David Pretel, El Colegio de México, dpretel@colmex.mx, www.davidpretel.com, CWPESH no. 31. See Pretel's book about spanish patenting system up to 1902: https://link.springer.com/book/10.1007/978-3-319-96298-6
• ‘The Desirability of an International System of Procedure for Protection of Invention’, Journal of the Society of Patent Agents, No. 44, 45 and 46 (1902–1903), p. 116.
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