During the first half of the nineteenth century, the French economy underwent a major technological change, with small and medium-scale entrepreneurs driving the industrialisation by developing and exploiting new technologies. This paper examines the life of one such entrepreneur, Hector Ledru (ca. 1798 to 1876), who started out in the sugar industry of the post Napoleonic era. He soon morphed into an entrepreneur exploiting patents in the manufacture of wooden barrel manufacture, galvanised iron and metal pipes, before he settled on the manufacture and installation of central heating systems. Ledru serves as an example of the archetypical small and later medium-scale entrepreneur making his way in post Napoleonic France, never reaching national fame, but all the way adjusting to the various social and economic circumstances.
A substantial body of literature has examined the emergent French industrialisation during the early and middle part of the 19th century. There appears to be consensus that the French path of industrialisation differed from that of the United Kingdom and the United States of America, due to both social constraints, and retarded infrastructure development. As a further important difference the conservative attitude of French entrepreneurs has been mentioned together with a lack of investment capital for start-up companies, in part caused by huge war reparations in consequence of the defeat of Napoleonic France. Innovation, however, was not stagnant, as French scientists and engineers invented a range of revolutionary technologies, from gas lighting and galvanised iron, to spinning machines and artificial dyes. While these technologies all contributed to the local and national industrial development, they ultimately flourished outside France.
The period from the 1830s to the 70s saw the most dramatic change. In France it was an age when one scientific discovery followed the other and when inventions were patented at unprecedented rates. The 1840s and 50s, in particular, were a period of major, yet gradual transition from individual small-scale artisanal production to either larger factories or to organized co-operating entities. While the gradual mechanisation of production, which accelerated in the 1850s and 60s, was a major contributor, it could only have an effect if the entrepreneurs espoused new ways of manufacture and thus were willing (and had the capital) to invest in such factory infrastructure. The re-design of Paris and the concomitant building boom and the associated modernisation of construction technologies, materials and processes percolated to other urban centres.
While the Central and Departmental governments played a major role in the economic development through the award of contracts, as well as the imposition (or absence) of tariffs and taxes, central to the economic development were individuals who acted as agents of change: scientists, inventors and entrepreneurs. An entrepreneur's interest in innovation counted for naught if he was unable to raise the required capital, or if his actions contravened or were constrained by social norms.
During the 1830s to 60s, France underwent a social change with the emergence of the self-made man, homo novus. In the shifting social framework, up and coming entrepreneurs, rising above their status, found themselves caught between opposing forces. The emerging industrialist bourgeoisie, which was shaping its own destiny, had to compete with to compete with, and differentiate themselves from the extreme manifestations of the capitalism of the nouveaux riches. In an age still characterised by the bipolar concepts of patrician and plebeian virtues, a new concept, that of bourgeois virtue, was gradually emerging, although it was not recognised as such at the time. Most businesspeople were confined with the existing social framework, which was further exacerbated by the dichotomy between Paris and regions. As businessmen held an inferior position in French society (as opposed to lawyers, administrators and the military and other notable professions), many felt a need to gain social respectability. While this could be facilitated by their own entrepreneurial prowess and reputation as reliable manufacturers, it required capital, which could be raised privately or on the stock market.
David Landes discussed the role of the French entrepreneur and his influence on French industrial growth during the 19th century. Landes characterised the French entrepreneur as a small businessman acting for himself drawing credit from limited clientele of trusted friends, fundamentally conservative and independent. At the same time, as businessmen held an inferior position in French society, most entrepreneurs aspired for social upwards mobility through marriage into aristocracy, either themselves or their children.. To date, we have only very few examinations of such individual careers, with Thomas' study of Jean-François Cail being the most detailed. In this he showed how a technologically-aware entrepreneur acquired wealth which he could then use to good effect to acquire patents of emerging technologies (e.g. railway locomotives) that filled demand. Further wealth and reputation followed.
Not all entrepreneurs, however, were as successful even though they too had unique opportunities presented to them. Some had to overcome self-inflicted hurdles, due to bad business decisions, such as ill-advised investments or purchase of patents of doubtful viability, as well as due plain mismanagement of unique opportunities. Some entrepreneurs gave up, while others refocussed their activities and rebuilt their businesses and careers. The following paper is a case study of one such entrepreneur.
Hector Ledru's starting point
In an age where the vast majority of consumer goods were manufactured from a variety of plastics, it is hard to imagine the impact that something coarse and drab as galvanised, i. e. zinc-coated iron would have had on the nature and life-expectancy of household goods and construction materials. While iron was a cheap, strong and ubiquitous material, it suffered from corrosion («rust») which severely limited its uses. The development of a commercially viable process to zinc-coat iron by Stanislas Sorel in 1837 dramatically improved corrosion resistance and thus significantly extended the use life of iron products. Not surprisingly, contemporary authors opined that the invention «bids fair to be one of the most important of the age».
The original patent was granted, effective 10 May 1837, to Hector Ledru and Stanislas Sorel and is mentioned, in that same order of names, throughout most of the legal references. While Stanislas Tranquille Modeste Sorel (1803 to 1871) is well known as an inventor, with numerous awards and medals to his name, including the Legion d'Honneur, comparatively little is known about Sorel's collaborator, Hector Ledru. Who was he? As will become evident, unlike Sorel who was primarily an inventor who dabbled in the commercialisation of his inventions, Ledru was much more the aspiring entrepreneur, whose business relationships seem to have been very closely interwoven with his private life. Ledru was not a very prominent businessman and as such has, understandably escaped the attention of historians. Thus Ledru can be regarded as representative of many small and medium-scale entrepreneurs of the French bourgeoisie which flourished with a modicum of success during the July Monarchy under Louis Philippe.
Hector Joseph Ledru was born about 1798 at Foucaucourt (Somme) as son of Joseph Philippe Robert Ledru and Victoire Cécile Bourdon. Philippe Ledru was a landowner and agricultural producer in Bullecourt, where he also served as mayor. Ledru is described as a patriotic ex-conscript soldier desirous to support his country. Hector Ledru's formative years occurred in the Napoleonic era, when France re-emerged from the turmoil of the Directorate that followed the French revolution. At the same time, he had to experience the death of his father at an age of 15 or 16, probably due to suicide caused by a failed investment (see below).
The Sugar Connection
Determined to break England's monopoly on sugar, and in particular in response to the English blockade of French ports (from 1806), Napoléon Bonaparte pushed for the development of a national French sugar industry using sugar beets to overcome the blockade of British goods. On 1 September 1812 Philippe-Joseph Ledru and François Chardanne, a land-owner at Douai, were granted a licence to produce sugar in Arras (Pas-de-Calais). A week later, Ledru and Chardanne formed a company, with an initial duration of one year. Lacking experience, Ledru took advice from Louis-Jacques Thénard, professor of chemistry at the École Polytechnique, who had published on sugar production. In January 1813 the first sugar was produced ay Arras. Later that year, the factory was in full swing, producing a quantity of brown sugar, syrup and rum, and pressed loaves of crystallised sugar. But in his rush to establish a sugar factory, Ledru had overlooked environmental concerns. As the factory was located in a residential area of Arras, it attracted complaints regarding noise, dust and smoke. The local court sentenced Ledru to move the boilers and the graters away from the location. A relocation of the machinery meant a major financial impost. The sugar factory effectively only operated for two seasons after which Philippe Ledru was forced to declare bankruptcy. It can be surmised that the set up and initial operational costs, combined with the relative inefficiencies of being a newcomer to a new technology and the required relocation, reduced any possible profits.
Philippe Ledru died at Bullecourt on 20 January 1814. Ribauxspeculates that Ledru committed suicide to maintain the family honour. On 16 March 1815 the factory was bought for 19,800 Francs by Crespel-Delisse, a sugar merchant from Lille, who not only restarted the works but also seems to have taken on Hector Ledru as an apprentice. Striking out on this own. Aged 29, Ledru first came to public attention in September 1827. At a dinner hosted by the city of Amiens for King Charles X, a large column of white sugar was exhibited as a table centre piece opposite the king. Charles X commented favourably on the quality of the sugar. That event was re-reported in various newspapers throughout France and even abroad. As far as can be ascertained, Ledru seems to have been involved in owning or running the sugar works at Franvillers (Somme) since at least 1825. In 1827 Ledru exhibited some of his sugar at the Paris national industrial exhibition, for which he was awarded a silver medal by the Société d'Encouragement pour l'Industrie, «both for the products and for the perfection that he has given his devices.» The latter suggests that Ledru had been engaged in advancing the sugar making technology in some way.
Warmé, in his 1828 essay on the sugar beet industry of the Somme, noted that Jeremiah Spencer, a British Quaker, had interested Ledru in the anti-slavery movement and that Ledru helped to distribute an anti-slavery publication. The fact that no further record can be found, however, suggests that Ledru, although prominent in the sugar industry of the Somme, was less interested in the anti-slavery issue out of conviction but more out of self-interest. After all, the cheap labour available to the owners of the Caribbean sugar cane plantations meant lower import prices for sugar that competed with Ledru's own sugar made from sugar beet.
With an annual output of 24.5 tons of sugar, and with 25.2 hectares under sugar beet cultivation, Ledru et Cie at Franvillers was a medium-sized sugar producer in 1827. The level of mechanisation at Ledru's factory is noted repeatedly. Ledru et Cie is listed among a large number of sugar manufacturers operating in 1829–30. By 1831 the works seem to have been running sufficiently well that they could be left in the hands of a foreman, Hilaire Boye, while Ledru occupied himself in running other factories.
Indeed, already in 1828 Ledru, together with Edouard Bertin, opened a second plant which operated as Ledru et Bertin at Roye. By 1835 that factory, then trading as Ledru et Cie, processed about 150,000 pounds of beet per day. In 1829 Ledru became a founding share-holder in the sugar factory at Francières, which he and Bertin established there with a broad range of investors (trading as Ledru, Bertin et fils). In April 1833, following a suggestion by Ledru, the factory at Franciers was purchased by Crespel-Delisse, who eventually also bought Ledru's Franvillers works.
It is worth noting here that the careers of Hector Ledru and Jean-François Cail were quite similar up to this point. Both came from poor (Cail) or impoverished (Ledru) backgrounds, both were apprenticed in the sugar industry, both went on to own sugar manufacturing companies, and both had a major interest in technologies. Whereas as Cail stuck, at least for the time being, to sugar production and embraced and actively financed the competition in the Caribbean (thereby increasing his wealth), Ledru opposed the Caribbean sugar industry as he perceived it as a threat to his livelihood. Rather than facing the new (and in essence old) realties of sugar production, Ledru made some dubious investment choices.
The Montesson affair
Some light on Ledru's life during that period is shed by the proceedings of a court case relating to the Société Agricole et Industrielle de Montesson, a very public spat about company mismanagement. In 1833 Brame Chevalier had invented a process that used steam to heat the sugar syrup to the required temperature, while at the same time using hot air generated by the steam engine to agitate the syrup. In consequence, the yield of sugar from the same amount of sugar beet was almost doubled. In April 1833 Brame came to Paris to market his invention. Possibly through the services of Hector Ledru, Brame came into contact with Hector's brother, the lawyer Charles Ledru.
Once patented, Chevalier set up the Société Narcisse Brame Chevalier et Cie to manufacture such machinery. Intriguingly, the registered company offices were located at rue Vingt-neuf juillet no. 6, the place where Charles Ledru lived. In the court case it was alleged that Charles Ledru had become a secret business partner of Chevalier's in contravention of the rule that lawyers were not allowed to engage in industrial businesses. In mid-1835 Chevalier, helped by a wide range of investors, established the Société Agricole et Industrielle de Montesson. Although not explicitly mentioned, we can assume that both Charles and Hector Ledru would each have been one of the many shareholders.
In the court case it was commented that Hector Ledru had been in almost daily contact with Chevalier from June 1833 onwards and that he had provided managerial advice on the application of the invention in practical, factory-operational terms. Hector Ledru appears to have moved to Montesson in late 1834 to supervise the set up and the operation of a new sugar refinery. Moreover, Ledru seems to have seen potential for the establishment of a sugar production in the south of France and appears in vain to have solicited Brame to co-invest.
When the Société Montesson went bankrupt in July 1836 recriminations began, especially as Brame seems to have been able to extract large amounts of funds before the company's collapse and otherwise acted dishonourably. The manager and creditors of Société Montesson obviously sued Brame. Another suit was brought against Charles Ledru and the notary François-Joseph Lehon for collusion and professional malfeasance. That suit was unsuccessful.
The court case was a widely observed event, not the least due to the fact that the case was so extensively reported in the Gazette des Tribunaux, a paper that had been founded by Charles Ledru. While the case did not damage Charles' integrity and reputation as a lawyer, the publicity must have affected Hector Ledru's standing in the sugar producing community; after all, the public parading of private correspondence between Hector Ledru and his brother, as well as with Brame Chevalier, shed light on behind the scenes machinations. Moreover, Hector Ledru had to publicly admit that he had been misled by Chevalier, a fact that would have damaged Hector's reputation as a judicious investor. This was compounded by the public admission that the Ledru family had lost a combined 400,000 Francs in the venture. Indeed, if we combine this with his gullibility in investing in Hainsselin's perpetuum mobile (see below), we may well doubt Hector Ledru's business acumen.
The 1837 entry in Bottin's almanac and address book neatly summarises Ledru's business interests at the start of his presence in Paris. At that time he resided with his brother and, presumably, had not yet acquired a manufacturing facility. Completed in late 1836, and presumably heavily based on how Ledru wished the information to appear, the address book entry reads:
«Ledru (Hector) operates throughout France a patented system of machines for manufacturing barrels; organizes mechanical sawmills and other machines for working wood; owns several such plants in Lille, Marseille, etc.; builds steam engines with all the mechanics, mainly machinery for the manufacture of sugar indigéne, and sugar from sugar beet, [resident at] rue du Vingt-neuf juillet nº 6».
The entry demonstrates that during the early 1830's Ledru had gradually abandoned his sugar production interests and morphed into manufacturer of machinery, initially for sugar production, and later for associated industries, such as mechanised saw mills.
Given the paucity of data, much is left to conjecture as to why Ledru moved from sugar production into other areas of manufacture. At the time, the sugar beet production was restricted to northern France and had only limited expansion options in the wider region. In addition, with the end of the Napoleonic blockade and import restrictions, the French market was once again open to cheap importation of sugar from British, but also from French colonies in the Caribbean and Central America. Moreover, competition had emerged and the local sugar beet industry had reached capacity. In short, there was only so much money to be made with sugar. On the other hand, the technological support industries in the form of sugar manufacturing machinery and allied technologies, as well as in the area of barrel making and other cooperage, allowed for expansion that was unfettered by geographic limitations.
The logical move was to develop a manufacturing base that allowed him to draw on existing business contacts and general goodwill in the region, but also to expand beyond. Consequently, Hector Ledru is listed as négociant in Lille in 1836.
Sometime in 1834 Ledru must have decided to expand his business interests in the south of France, for in February 1835 we find him also residing at rue de Paradis no. 125 (or 135) in Marseille. There he seems to be acting on behalf of Delamarche de Manneville to manage de Manneville's rights to Jacques-Nicolas Legendre's patent for the machine-driven manufacture of barrels, drums and similar vessels, as well as pieces of wooden flooring. In a number of advertisements in Orleans as well as Lyon, Ledru can be seen canvassing potential investors to take up the production rights especially in Burgundy and in the south. We do not know how successful that venture was.
It seems that in early 1836 Ledru went into the cask making business himself, again drawing on his business contacts, and presumably his name and general reputation in northern France. On 1 March 1836 Ledru and the merchant d'Athis, formed the firm Hector Ledru et Cie, based in Lille. The company acquired (from Delamarche de Manneville) the rights to the manufacture of barrels, drums and similar vessels, but was geographically limited to the departments Aisne, Pas de Calais and Nord. On 3 July 1837 Ledru and d'Athis on-sold these rights to Fréderic Kuhlmann, a merchant in Lille. It is likely that at or about this time the business partnership between Ledru and d'Athis was restructured, with Ledru reducing his presence. Address books show, however, that the company Dathis and Ledru continued to operate steam driven sawmills for the manufacture of barrels and flooring in Haubourdin near Lille between 1837 and 1842. A second sawmill and factory, operating between 1841 and 1847, was located in Crèpy. Yet another steam driven sawmill was located in Lille itself, solely owned by Ledru from at least 1839 to 1847.
Despite his ongoing investment in the saw milling industry in northern France, presumably augmented by some form of income from sugar refining (until at least 1835), Ledru appears to have maintained a presence in Marseille. There he seems to have chased, without a specific focus, economic opportunities as they developed and came to his attention. A good example of this is his partnership with Pierre-Nicolas Hainsselin. The latter had invented a machine which he called the Moteur Chimico-Physique and which was described as being «not dangerous, producing no or very little smoke, which can be applied to anything, and designed to replace the steam with advantage and economy». On 24 February 1835 Hainsselin and Ledru entered into a partnership to exploit Hainsselin's patent of the moteur chimico-physique. The resulting Société H Ledru, Hainsselin & Cie was to have a life time of twenty years. Hainsselin brought the patent into the partnership, while Ledru brought in 10,000 Francs, of which 4,500 Francs were a direct payment to Hainsselin and 5,500 Francs were destined for the company operations budget. Ledru was to become the sole manager of the company.
Alas, the invention, which promised to provide cheap and safe power to the people, and a handsome income to Ledru, was a total failure. Like the 1833 version of Hainsselin's machine, it was, in essence, a perpetuum mobile: «[a] machine, the nature of which depends on the descent of an endless series of reservoirs filled with water, which water is raised to suitable elevation for the purpose, principally by the action of the machine itself». Although patented both in France and abroad it was, of course, unworkable. Technically impossible, it never saw the light of day, let alone production.
In essence, Ledru fell victim to his own greed. This enterprise was so far outside the norm of his previous activities and experiences that he could not judge its practicability. A payment of 10,000 Francs was quite a sizeable investment. We can only surmise to what extent Ledru could recover some of his investment. Ledru may have been able to retain most of the 5,500 Francs to be spent on the company's operations, but would have lost 4,500 Francs. To put this into context, at the time, the price of a one-kilogram loaf of bread was 35 Centimes and the cost of two litres of red wine fluctuated between 28 and 36 Centimes; the average annual income of a worker was 500 to 720 Francs depending on the department.
It seems, however, that in the bigger scheme of things not all was lost and that Ledru may have gained some technological insights from the failed invention, for on 18 August 1835, together with François Saget, he registered a patent for a portable hydraulic machine for the lifting of water to various heights and other applications. Over a year later, on 23 December 1836, he filed for another patent for a hydraulic machine, this time on his own, and in his capacity as a ‹négociant à Marseille.› Following the Hainsselin fiasco, Ledru seems to have refocussed his priorities. In 1836 Claude David had invented a machine to manufacture casks and barrels. He licensed both Ledru and the engineer Marie Claude Philippe to manufacture and distribute these machines, but also sold drums and barrels himself. As this was an extension of his existing business line, Ledru became interested in the invention.
A Société Hector Ledru et David was formed on 9 December 1836 to be amended on 18 February 1837 as Société Hector Ledru, David et Cie, created in order to exploit Claude David's patent (of 28 September 1836) for the manufacture of casks. On 18 February all rights to David's patent were transferred to the company, with some geographic exceptions. In September 1840 a new company was formed in Paris, which formally merged Delamarche de Manneville's business interests with those of Ledru, David et Cie, and a Francois Lemaître. That company seems to have operated with some success, but was wound up on 20 October 1842. As part of the restructure, two new companies were formed. On 23 November 1842 (amended on 5 December), Ledru, David et Cie granted the rights to David's patents to Delamarche de Manneville, with the exception of certain northern departments. On the same day, a new company was formed in Paris, which merged Delamarche de Manneville's business interests with those of Ledru, David et Cie, and Francois Lemaître. The company, which also registered on 26 April 1843 in Calvados, was set to exploit David's patent in Paris and the northern departments not covered in the previous sale.
One of the unanswered questions of this period relates to the nature of Ledru's continued shareholdings in the sugar industry. While he was no longer the lead partner and manager, Ledru would have retained some stake in the business(es) to ensure an income stream. At one point in time he is likely to have sold that stake, but we do not know when. The social divide between the metropolitan centre and regional communities was, and to a large degree still is, very pronounced in France. Paris was the centre of the universe, even though it had lost some of its geopolitical clout in the immediate post Napoleonic era. Being a person of influence in regional towns like Amiens, Lille or even Marseilles, counted for little in Paris. Having been presented to King Charles X also meant nothing after the July 1830 revolution. Even the only thing that may have counted, the silver medal that had been awarded to him in 1828 for his contribution to the sugar industry, counted for little as he focussed on areas outside the field of sugar. Thus, in effect, Ledru had to start all over. In this, however, he was of course aided by the capital at his disposal. At the same time, the Louis Philippe reign was one of emergent capitalism and social upwards mobility that this entailed. Ledru was well placed to take advantage of that.
Some time in late 1834 or early 1835 Ledru is on record as having moved to Paris, taking up residence at rue du Vingt-neuf juillet no. 6 in the Ier arrondissement, which, given its closeness to the Tulieries was quite an ‘upmarket' area. He may have rented an apartment of his own, or he may have moved in with his brother Charles, who was a lawyer admitted to the royal court.
Some time in 1836, or before, Hector Ledru became married to Adèle Constance de Vinoy, of rue Trois Bornes 15. It proved to be very difficult to illuminate the background of Adéle de Vinoy. While the name is not that common, not much could be found that extends beyond information on Adéle herself and her business Vinoy et Cie. She, and the business associated with that name, only appears in the public record from 1843 until December 1844 (see below). Their daughter Adèle Sophie was born in Paris in June 1837. Given the paucity of genealogical data, we do not know whether the Ledrus had any other children.
The various appellations given in the directories, as well as legal documents, allow us to trace how Hector Ledru's standing in Paris changed over time. In 1839 he is described as a barrel maker (tonnelier), but soon after labelled a négociant in 1841, a mécanicien in 1843, inventor in 1844, and finally, from July 1844 onwards, as a civil engineer.
Based on the perusal of a broad array of sources we can compile a chronology of residences and factories associated with Hector and Adéle Ledru (Table 1).
|Address||Period on record||Function||Sources|
|rue des Trois Bornes nº 14||1839–1843||residence and factory|
|rue des Trois Bornes nº 15||1844–May 1845||residence and factory|
|rue d'Angouleme–du–Temple nº 40||31 Jan 1841–1844||factory|
|rue d'Angouleme–du–Temple nº 42||May 1845–Jul 1850||factory|
|rue d'Angouleme–du–Temple nº 46||1839||factory|
|rue d'Angouleme–du–Temple nº 46||Sep 1851||factory|
|boulevard du Temple nº 46||1841|
|boulevard Poissonniére nº 18||1841–1842||main depot, H Ledru et Cie|
|rue Basse nº 41, Passy||1854|
|passage de Grenelle-Saint-Germain |
|rue du Champ de Mars nº 3||1864||residence|
|rue Hauteville 64||July 1857–Apr 1858||factory|
Sources: Lamy, Annuaire 1839, 1841 (cf. n. 72), 530, 646; Cambon, Almanach 1843 (cf. n. 73), 184, 266; Thénard, Rapport de Jury Central (cf. n. 106), 963; Louis Philippe, Nº 9,385–Ordonnance du Roi portant proclamation des Brevets d'invention délivrés pendent le premier trimestre de 1841, p. 857 no. 63; Bottin, Almanach (cf. n. 108), CCXL, 220, 456, 588; (Adéle Ledru) Louis Philippe, No. 11,958–Ordonnance du Roi portant proclamation des Cessions des Brevets d'invention, in: Bulletin des Lois du Royaume de France 30 (1845), 474–483, 479f., no. 34; Hector Ledru, Louis Cheret, and Cie, Tuyeaux étirés a froid galvanisés, in: Gazette des Tribunaux 20 (1845), 4; Louis Buffet, Rapport de Jury Central sur les produits de l'agriculture et de l'industrie exposés en 1849 Imprimerie Nationale, 1850, 418; République Française, No. 3,214 (cf. n. 179); Roquebert, Sociétés Commerciales, in: Gazette des Tribunaux 22 (1847), 804; (Adéle) Napoleon III, No. 812 Decret qui proclame 390 brevets d'invention et certificats d'addition du 1er Decembre 1852, in: Bulletin des Lois de l'Empire Français 12 (1853), 565–618, 616 no. 523; Listed as civil engineer, rue Faubourg-Poisonniere 28 in July 1844. Henrichs, Annuaire Gènéral du Commerce 1847 (cf. n. 142), 177; Today rue Raynouard. (Adéle) Napoleon III, No. 2,297 (cf. n. 109), 62 no. 150; (Adéle) Napoleon III, No. 11,994 (cf. n. 112); Napoleon III, No. 14,172 (cf. n. 113); Sebert, Societés, in: Gazette des Tribunaux 32 (1857), 710; G. Rey, Societés, in: Gazette des Tribunaux 33 (1858), 392.
By 1844 Hector and Adéle Ledru had moved to rue Faubourg-Poisonniere 28, where he is on record until at least 1851. Judging from the address books and other references, there is no evidence that Ledru resided in Paris in 1854 to 1856, but we find them (at least Adéle) again mid 1854 living at rue Basse 41, Passy, and again in July 1857, residing at rue Hauteville 64. From other evidence it appears that the Ledru's seem to have lived, at least for part of the year, in Geneva. By 1862 the Ledru's resided at the passage de Grenelle-Saint-Germain 11, and finally, in 1864, at the more upmarket address of rue du Champ de Mars 3 in the first arrondissement.
The Societé pour la Galvanisation du Fer
In late 1836 the French watchmaker and inventor Stanislas Sorel (1803 to 1871) developed a commercially viable process to protect iron from corrosion using the galvanic differential between the zinc and iron. Sorel developed five different techniques, of which hot galvanising and cold galvanising (by way of paint) were the most significant. While we know that in late 1837 both Stanislas Sorel and Hector Ledru resided at the same address, rue du 29 Juillet 6, their relationship seems to predate this. It is not clear how Stanislas Sorel and Hector Ledru met, but both seem to have had some connection with the French sugar beet industry. Ledru's connection has already been mentioned above. In January 1835 Sorel had entered into a partnership with Adrien Jean Pierre Thilorier and Bernard Serrurot exploiting a sugar extraction patent and in subsequent years seems to have researched aspects of sugar extraction. In addition, both Ledru and Sorel came from the north of France.
Given that Ledru had no prior experience in metal manufacture, let alone metallurgy, one wonders why he is listed on the patent. It is unlikely that he had any intellectual input in the invention. Indeed, a year after the patent was registered, Sorel was recognised by the Société d'Encouragement pour l'Industrie Nationale with a silver medal, but no mention is made of Ledru. In the absence of any archival data one has to speculate. But it appears reasonable to assume that Ledru financed some or all of Sorel's work and thus had his investment secured by being named co-owner of the patent.
In early September 1837 Sorel and Ledru, aided with additional funds provided by Isidore Catheux formed the Societé pour la Galvanisation du Fer with an initial capital of 100,000 Francs. On 9 January 1838 the company decided to raise its capital to two million Francs through a public share offering, issuing 2,000 shares of 500 Francs to the public and 2,000 non-voting shares to the three primary shareholders. When formally listed on the Bourse de Paris on 19 March, the stock opened at 3,000 Francs, six times the face value of the shares. The extreme speculation was widely reported in France and other countries, such as Germany. The wild fluctuations of the market were influenced, if not caused, by active manipulations of the share price and gullible investors.
Not all investors can be viewed as largely clueless rapacious speculators though. Once Sorel, Ledru and Catheux had agreed that they would not use their share parcels to vote in the annual general meetings, John Cockerill, one of the leading European industrialists of the time, took up a parcel of 500 of the 2,000 non-voting shares on offer. Despite Cockerill's stature as an industrialist and investor and despite the patent being taken up overseas, the share price continued to slide.
In June 1838a business reporter of the journal La France Industrielle, Manufacturière, Agricole et Commerciale took up the issue of the apparent failure of the Societé pour la Galvanisation du Fer. The writer noted that a broad range of applications had been touted, which had set up an expectation among the speculators and small-time investors that galvanisation was the wonder cure for all technological ills. The failure of the Societé pour la Galvanisation du Fer to gain traction seems to have been squarely sheeted home to the board of directors. Instead of rapidly developing and building the factory to produce marketable products, the company spent all its energy on publicity, the generation of what amounts to pure hype, testimonials to the quality of the process and newspaper pieces that extolled the range of applications. Consequently, the investors became disillusioned and abandoned the stock.
Given the prospects of the invention and given the meteoric rise of the shares during the first few days, it is not surprising that Sorel et Cie soon encountered competition, not only in France, but also abroad, such as in England, Germany and Belgium. By late 1839 it had become obvious that the current management structure, with the diverging objectives, was no longer workable. Thus, at its annual general meeting on 26 December 1839, the shareholders of the Société pour la Galvanisation du Fer unanimously supported the motion that both Sorel and Catheux were to step down as managers, and that the sole management of the company was to be carried out by Hector Ledru. To reflect that change, it was further agreed that henceforth the company be called Hector Ledru et Cie.
Ledru managed the company competently, but not brilliantly. For unknown reasons Hector Ledru stepped down as managing director of Hector Ledru et Cie on 6 March 1844 and appointed Claude Rabatel, rue des Trois Bornes nº 15, as interim manager. At the general meeting on 26 March 1844, Ledru's resignation was accepted, Baron Saint Pol was appointed sole manager, and the name of the company formally changed to Saint-Pol et Cie.
Even while involved in the Societé en Commandite pour la Galvanisation du Fer, Hector Ledru seems to have founded and run a number of companies in parallel. His interests in the manufacture of barrels and saw milling equipment (see above) continued. At the same time, Ledru also dabbled in other inventions, some of which seem to have been opportunistic. An example of this is a patent for a «simple and novel process for dyeing wool and all wool fabrics in blue colour of a nice shade, called bleu Napoléon, and all the nuances of indigo that can be obtained, such as green-black, olive, bronze and other colours without actually using indigo». This patent was awarded on 8 May 1839 to Ledru as the lead patentee together with the cloth dyer Jean Baptiste Laurent. The only connection between them, as far as we know, was that both resided at the same address, rue 29 julliet 6, then in Paris' arrondissement. The patent was annulled on 1 January 1841 and never seems to have been exploited commercially to any noticeable degree.
During and after the separation from his galvanising business, Ledru pursued further inventions and developments primarily in the field of pipes, closely linked with Vinoy & Co. In 1843 Ledru invented the concept of manufacturing pipes from long strips of galvanised sheet iron. The seam had edges that were folded over, which could be connected by a long piece of metal acting as a clamp. Once soldered, they were water and airproof. Contemporary sources noted that drawn iron tubing had been invented in England, but had relied on hot metal. Cold drawn tubing, as developed in France, was seen as «in every respect perfect, indeed much more perfect than the hot-drawn tubing. »
To capitalise on the invention, the Société A de Vinoy et Cie, manufacturer of pipes, was founded in 1843, trading from rue de Trois Bornes 15. A de Vinoy et Cie exhibited their pipes in Paris at the French national industry exhibition of 1844, where they were awarded an honourable mention. It remains unclear why the Ledrus decided to set up Vinoy et Cie as the vehicle for manufacturing pipes. It could well be that this was an attempt at separating the pipe manufacturing business, which Ledru clearly perceived to have a future, from the galvanised iron business that had run into stagnation. The relationship between de Vinoy et Cie and Ledru et Cie was most certainly very closely interwoven both personally and spatially. The initial residence and factory had been at rue des Trois Bornes nº 14 from 1839 onwards. It was expanded with the factory erected at rue d'Angoulême-du-Temple nº 40. The factory premises were directly opposite the residence which straddled the block between both streets. It was an ideal set up. In late 1843 Ledru established the de Vinoy pipe works. By that time they had moved to the larger residence at rue des Trois Bornes nº 14, across the road from nº 14. The pipe works were established at rue d'Angoulême-du-Temple nº 40, next door to nº 40, which allowed for an efficient work flow.
The citation for the honourable mention at the 1844 exhibition notes that while de Vinoy et Cie manufactured the pipes, «all work [was] performed under [Ledru's] direction and by his advice» The Austrian architect Paul Sprenger visited the factory in late 1844 and provided the following description:
«Mr Lambaux took out a patent […] for the manufacture of pipes for gas lighting made from single and double galvanised iron sheets (i. e. galvanised iron made according to Mr Sorel's process), which is carried out by Mr de Vinoy, rue des Trois Bornes nº 15.
While so far none have been used in Paris, Mr Sprenger saw pipes being made in the small factory to fill an order placed by Havanne (a small town).
The connecting pieces are soldered, and the galvanising of the two pipes which have been slotted one into the other occurs in another factory of Mssrs Ledru and C, rue d'Angouléme du Temple nº 40. Mr Ledru's opinion regarding these pipes suggested that the business, even for pipes with a smaller diameter, would be profitable as their cost was less than half of that of lead pipes, but when tested, they withstood a pressure of more than 40 atm without rupturing.»
Sprenger's comments are illuminating in two ways. They confirm the close working relationship between de Vinoy et Cie and Ledru et Cie, and they underline Hector Ledru's central role. It appears that Ledru and his wife set up a corporate structure, whereby the pipe manufacturing business was a separate commercial entity, in her name (see below), that served as a feeder industry to the galvanising business.
While the galvanising business could provide a broad range of consumer goods, such as horse bits and stirrups, watering cans and drums, the major growth market lay in the area of domestic and public construction. During mid-nineteenth century France two areas spring to mind: the manufacture of galvanised corrugated iron for roofing and the production of galvanised iron pipes for water and especially for gas. The latter service was to become a major growth industry of the period as both public lighting and then businesses and private homes converted to gas.
When considering Ledru's options, we also need to appreciate the interconnectivity of the issues. While his products could serve a number of markets, new markets opened up, or became feasible specifically due to the products. Thus galvanised iron pipes could be used to pipe water and gas. The provision of gas became more feasible with the introduction of galvanised iron pipes as they were more resistant to the corrosive effects of the gas, which in turn allowed more gas to be installed. Thus to some degree, Ledru's galvanised iron business was at the cusp of developments, the true profits of which were reaped by successors.
From a manufacturing point of view, a galvanised iron manufacturer needed to acquire pre-manufactured items for galvanisation. Thus his business was largely limited to value-adding. In the ideal world, however, the manufacturer would reap profits all along the production chain. Indeed, two or three decades later, British galvanised iron manufacturers perfected the closed production chain, starting with iron ore procured from their own mines, which was melted into bars in their iron foundries, which in turn delivered them to their own mills where the iron bars were cold-rolled into sheets which could be delivered to final galvanisation and subsequent corrugation. Ledru went some way along this line, by investing in the de Vinoy and Cie pipe works.
The restructure of 1844
The year 1844 seems to have become a turning point for Ledru. Then aged 46 he seems to have once again re-focussed his efforts. The Paris address book for 1844, compiled in 1843, shows that Ledru carried out a general engineering and manufacturing business, still selling apparatuses and machines for the fabrication of ‘native sugar' (from sugar beet), galvanised iron and steel, corrosion-protected copper, furniture made from galvanized iron, steam engines and boilers, equipment to prevent steam engine explosions, fire temperature controllers, as well as a thermostatic syphon. Many of these were based on inventions by Stanislas Sorel. By late 1846 the principal business had shifted. Ledru, Cheret and Cie primarily sold cold extruded pipes made of copper and galvanised iron sheets, for steam, water, and gas as well as suction pumps. The galvanising business no longer figured in the manufacturing line up and it appears that Ledru had become a customer of galvanising works, rather than a manufacturer of the product.
By the end of January 1845 the production and distribution had been formally taken over by Hector Ledru et Cie. On 1 March 1845 Ledru is joined by the merchant Louis Cheret to form Hector Ledru, Cheret et Cie as successors to A de Vinoy et Cie.
Ledru's pipes were lauded as a possibly very safe design, which would greatly aid public safety as gas explosions caused by burst pipes were not uncommon. Throughout 1845 Ledru et Cie advertised their products both for the domestic and the French colonial markets. Ledru himself gave presentations and published a number of papers on the cold drawing of pipes made from copper, sheet metal and galvanised iron. In 1845 and in following years, Ledru seems to have visited England, presumably to develop business contacts.
The partnership between Ledru and Cheret was dissolved by mutual agreement on 1 June 1847. The company immediately transitioned into a new configuration, with the merchant Pierre Robin stepping in as sole manager. Robin and his partner brought into the new company all their previous manufacturing assets at rue Angouleme-du-Temple nº 42, while the Hector and Adéle Ledru brought in the patent rights for all of France. It is not clear whether these also included the rights to a patent for a machine to manufacture a certain type of pipes which Hector Ledru filed on 25 May 1846 (with additional filings until July of the same year). Ledru patented this invention also in England, Belgium, Austria and Bavaria. In December 1846 Ledru appears to have licenced the production of the pipes to the start-up company de Baillehache, Desforges et Cie, but little is known about that company and whether it ever produced pipes.
By 1849 Robin et Cie, then trading as Ledru, Robin et Cie, was awarded a bronze medal for the design at the Paris industrial exhibition of 1844, despite its problems.  Ledru's design had proven to have some faults, especially at the joints, which soon led to rival patents.
Adèle Constance de Vinoy
As discussed above, it proved very difficult to shed much light on the background of the company Vinoy & Cie. In the French sources, the company is only ever referred to as «A de Vinoy et Cie.» At the Paris exhibition of 1844 the pipes were listed as being produced by «Mr de Vinoy» Consequently, an Austrian technical journal indicates that the owner of de Vinoy et Cie, working from rue des Trois Bornes 15, was a male. Even contemporary sources seem to have been confused by the arrangements, as the citation to the honourable mention notes that
« [t]hese products were exhibited under the name of M[onsieur] de Vinoy; but it is clear from a letter addressed to the president of the jury by M[adame] A. Vinoy and Cie, that Mr. Hector Ledru invented devices that are used to manufacture these pipes, and that it [Vinoy and Cie, ed.] sponsors the establishment where they are made, and in which all work is performed under his direction and by his advice; therefore Mr. Hector Ledru personally receives, on the formal request of M[adame] A. Vinoy and Co, the prize awarded by the jury».
Perusal of the patent registers shows that Adèle Constance de Vinoy registered patents with the permission of her husband, Hector Ledru. One might assume that this was a structure specifically designed to hold the potentially lucrative rights to patents separately from the business and thereby both ensure a revenue flow, but also safeguard the patent as a separately owned asset in case the business failed. Upon investigation, however, it becomes evident that Adèle de Vinoy is on record as an inventor and businesswoman in her own right.
For example, on 27 July 1844 she acquired, in her own commercial capacity, the rights to Joseph Zambeaux's invention of 17 April 1843 regarding clean pipes for all uses. Subsequently she registered under her own name, improvements of Zambeaux's patent on 2 October 1844. On 15 April 1845 Mdme Ledru sold her rights to Joseph Zambeaux's patent as well as her own improvements to that patent to Hector Ledru, Cheret et Cie. Additional improvements of Zambeaux's patent were registered by Adèle Constance de Vinoy on 14 January and on 4 February 1846, but in these cases, Hector Ledru, Cheret et Cie also acquired some of the rights.
On 6 January 1848 Adèle Constance de Vinoy registered under her name a patent for a central hot air heating system for large buildings (see below). As «Mdme de Ledru, née Vinoy (Adèle Constance) » she is also listed on 13 June 1853 as the inventor of the turbine ‘hydro-atmosphérique.'
The Heating Business
The manufacture of pipes for gas and water systems, combined with an earlier interest in heating systems for sugar works, and combined with his wife's interests, gave rise to a new line of business that was to dominate the rest of their lives: central heating systems for public and private buildings.
As noted above, on 6 January 1848 Adèle Constance de Vinoy registered under her name a patent for a central hot air heating system «for theatres, public buildings, hospitals and the like. » She filed additions to the patent on 10 February 1848, 8 July 1850, and 25 September 1851. From 1849 onwards Ledru started selling Chaussenot's dry air heaters, an early form of central heating. In parallel, Ledru continued their development to maximize the fuel efficiency. He obtained a French patent, which was also registered in Britain and Scotland (Figure 4).
Ledru involved himself in additional capitalist ventures if they were related to his gas and heating business. Thus on 9 July 1857 the Société du Carburateur Launay was formed in order to exploit Théodule Charles Launay's patent for a carburettor that improved the brightness of gas lighting. The commercial structure was the Société Guillard, Ledru et Cie (rue de Rivoli 164), established for twenty years with a capital of 150,000 Francs, and comprised of a partnership between Marie-Joseph Gulliard, Hector Ledru, Jules Cropin, Théodule Charles Launay and other parties. Both Guillard and Ledru were appointed managing director. The company soon represented itself to the broader public as a manufacturer of «heaters with great perfection and economic usage, suitable for apartments, shops, and factories» and installed demonstration devices in a number of locations. On 12 November 1857 Guillard was replaced as one of the principal managers by Alexandre François Vaudorè. While the general trading name continued, the managing company now became Vaudorè, Ledru et Cie. Vaudorè and Ledru sold their patent rights on 16 December 1857. That company in turn was liquidated on 7 April 1858. Intriguingly, in their entry in the 1858 address book, Guillard, Ledru et Cie claim that the carburettor manufactured by them created 50 per cent savings on gas consumption, while an 1858 advertisement guarantees a saving of 40 per cent. These are bold figures that, if true, would have resulted in substantial savings to their customers.
The final chapter of Ledru's life takes place in Brignais near Lyon. While French society allowed for some upward mobility, the nouveaux riches, the self-made men, were still socially frowned upon. In addition, the political scene had changed. Louis Philippe's reign had come to end in 1848 with the creation of the short-lived French Second Republic, and from 1851 on with Napoléon III's Second Empire. The social policies of both gave more rights to workers, curtailing the powers, and profits of employers, with medium-size companies most affected.
In January 1856 Ledru installed a heating system in the Cathedral of Basle (Switzerland) which performed so well that it attracted much attention in Switzerland and France. In late 1856 Ledru advertised in some Swiss papers that he had appointed Achille de Bournonville as director of his Geneva establishment, noting that de Bournonville had gathered much «theoretical and practical knowledge while employed by the Corps des Ponts et Chaussées. »
Ledru, together with Achille Louis Albert de Bournonville, formed the ‹Société des Chauffages par les Calorifères› operating from Paquis in Geneva. In his marketing strategy for the central heating systems, Ledru seems to have followed the same formula he had already employed for when marketing galvanised iron: issuing publications that reproduce a technical appraisal, preferably the citation for the award of a gold medal, followed by a broad array of testimonials. The heaters found wide appeal and were installed throughout France and Switzerland, as well as in Belgium and the Kingdom of Sardinia. The 1860 book of testimonials lists 690 individual establishments in close to 250 towns, with almost two thirds of them in France. In 1865 they published a four-page pamphlet in which they set out some examples of heating installations and their operational costs. In the pamphlet they claim to have installed 25,000 systems, whereby it is not clear, whether this refers to separate sites. The hot air heaters, however, were not universally liked by factory workers. The patent registers show that Ledru and Achille Antoine Maximilien de Bournonville patented a new system of hot air heating on 2 May 1862, which was added to on 15 March 1864, with further patents in the same field in 1868.
On a personal level, however, Ledru achieved some mobility in 1857 as his daughter married Adèle Sophie Ledru married Louis Albert Antione (Achille) de Bournonville, the son of Ledru's business partner Achille Louis Albert de Bournonville The de Bournonvilles, an old established family with roots in the Artois, Boulonnais and Flanders, could trace their ancestry back to 1099. It seems that in 1864 or 1865 the elder de Bournonville withdrew form the business, and the company share went to Ledru's son in law, Albert Achille Louis de Bournonville. Upon the latter's death in 1872 Ledru appears to have continued to run, or at least supervise the company until it was eventually dissolved on 20 June 1872. Achille's widow, Adéle Ledru (together with Placide Munaret, who had been appointed ‘surrogate guardian' of the minor Heléne de Bournonville), was forced to sell the family home, a maison burguois, on 21 December 1872. A price of 20,000 Francs had been set by the courts.
Hector Ledru died on 28 July 1876 at Brignais. It appears that the remaining assets of the Société Ledru et Achille de Bournonville were then liquidated. The last remaining assets, it seems, were the patent rights which still had been held at that time by the Société Ledru et Achille de Bournonville; they were sold in 1876 by the company's liquidator to Edmond Moise Oulman who then on-sold them soon after.
Hector Ledru–an archetypical nineteenth century French entrepreneur?
Was Hector Ledru the archetypical nineteenth century French entrepreneur? We can only speculate what shaped Ledru as entrepreneur, but it appears reasonable to assume that the bankruptcy of his father would have been a primary lesson. Philippe Ledru was an ex-soldier turned land-owner, who had partnered with a second, likewise unskilled entrepreneur and invested the entire family fortune in a single, ultimately ill-fated venture. Throughout his career, Hector Ledru seems to have favoured a business model of a range of small-scale partnerships, preferably with him as manager (Table 2). Having a small number of partners both spread the financial risk whilst at the same time avoided interference by outsiders. In all bar one case Ledru was the manager and principal stakeholder.
It appears that in only a single instance, the Société pour la Galvanisation du Fer, did Ledru ever hold a major stake in a public shareholding company. His earlier experiences with fraudulent behaviour of the manager of the Société Agricole et Industrielle de Montesson would have demonstrated to Ledru that unless he had some sort of managerial control he could not be sure of his investments. But even when in a managerial position, his experience with the concept of a public shareholding company must not have been favourable. A first he was co-manager of the Société pour la Galvanisation du Fer together with Stanislas Sorel, who was far more interested in the kudos that the invention brought him among the scientific community than in actual business applications. Not surprisingly the company was without focus. Once Ledru became the sole manager of the company, it may well have irked Ledru to have been subject to a scrutiny by supervisory board (conseil du surveillance) and to be answerable to a broad array of shareholders at the annual meetings. As such then Ledru fit Landes' characterisation of the French entrepreneur as highly independent, with his firm being «pretty much self-sufficient» also applies well to Ledru. Again, with the exception of the Société pour la Galvanisation du Fer, which essentially was a service industry, all of Ledru's ventures were stand-alone industries with ample growth potential. All required capital was either self-generated or leveraged from acquaintances. Setting aside his early involvement in the sugar industry and the inherent risk factors of variable harvests, Ledru ensured that he was independent on factors over which he had limited control.
It is this independence and conservativism that would have limited his ability break into the league of major entrepreneurs. One can only speculate what might have happened if John Cockerill's investment and involvement had come to fruition.
Unlike Landes' depiction of the French entrepreneur as «a fundamentally conservative man, with a firm distaste for the new and unknown,» however, Ledru embraced new technologies. He seems to have been an early adopter of mechanisation when involved in the sugar industry. From then on, Ledru seems to have sought out what he considered viable patents, or in the case of galvanisation, funded the inventor, and subsequently formed companies that exploited these patents. He also seems to have been reasonable judicious in divesting himself of assets when their growth potential had peaked. Examples for this are his withdrawal from the sugar industry, and later his withdrawal from the saw milling machinery businesses. In most instances he seems to have done well with his investments, but on occasion he badly misjudged the opportunities, whether due to gullibility or greed. Examples for this are the investments in Hainsselin's perpetuum mobile and Laurent's Napoleonic blue dye.
Not until late in his career did Ledru morph into a more conservative entrepreneur, investing in and successfully running a major company installing centralised heating systems throughout northern and eastern France as well as western Switzerland. Ledru had become an established major figure, who, through his daughter's marriage, could even, at least in part, fulfil the ambitions of upwards social mobility so desired by the nouveaux riches.
Yet, not quite. Hector Ledru came from a rural background, his father a former soldier who had recently acquired land. When his father went bankrupt, landed family was a life to which Hector had no hope of returning. Rather, he sought to make his mark in the fields of business and industrial production. As the various layers of the evolving Bourgeoisie began to differentiate in the sense of Daumart, Ledru occupied and navigated spaces in the second tier, made up of proprietors of smaller enterprise, layers and higher state employees and the like. He never really managed to break into the top level, that of major merchants, bankers and industrialists.
While his sugar exhibit on the King's table in Amiens in 1827 had attained national and international mention, Ledru's subsequent business career was largely private. He secured some mention in journals that were published by professional societies of the day, but was not prominent in the public eye. As he grew older, and his business became more lucrative it seems, he dropped back into obscurity. As such he is an archetypical of French entrepreneur, most of whom were second-tier rather than the beacons of industrialisation– and like most have never been examined in any depth.
On a broader scale, Ledru exemplifies the gradual and incremental pace of industrialisation of the French manufacturing sector. A steady pace of progress in a range of sectors, none of which was dramatic and revolutionary. And where, as in the case of galvanisation, a truly revolutionary invention was at hand, its commercialisation almost timid. As such, then, Ledru is good example of a medium-scale French entrepreneur of the nineteenth century, who through his own work and business acumen rose above his upbringing, but who, due to circumstances or personal reticence and lack of risk taking, never broke through to become a truly notable figure in the business world.
|name of Société||Period||Partners||Siége||Line of Business |
|1||Ledru et Cie||1825–1835||HL, & others||Franvillers (Somme)||sugar|
|2||Ledru et Bertin||1829–1835||HL, Edouard Bertin||Roye (Somme)||sugar|
|3||Ledru, Bertin et fils||1829–1835||HL, Edouard Bertin |
|Francières (Seine et Oise)||sugar|
|4||Hector Ledru||<19 Feb 1835||HL||barrels|
|5||Hector Ledru et Cie||<1 Mar 1836–|
3 July 1837
|HL, M d'Athis||wooden barrels and flooring|
|6||Dathis et Ledru||1839–1845||M d'Athis, HL||wooden barrels and flooring|
|7||Hector Ledru, Hainsselin & Cie||30 May 1835–||HL, Pierre-Nicolas Hainsselin||rue du |
29 Juillet 6
|8||Hector Ledru et David||9 Dec 1936–||HL, Claude David,||casks|
|9||Hector Ledru, David & Cie||9 Dec 1936–|
|HL, Claude David, Marie-Claude-Eugéne Philippe||casks|
|10||Sorel et Cie||21 Sep 1837|
26 Dec 1839
|Stanislas Sorel, HL, Isodore Catheux|
(Societé pour la Galvanisation du Fer)
|rue de Trois Bornes 11||galvanised iron|
|11||Hector Ledru et Cie||26 Dec 1839–|
26 Mar 1844
|HL, Stanislas Sorel, Isodore Catheux, John Cockerill||rue d'Angouleme-du-Temple 40||galvanised iron|
|12||A Vinoy et Cie||1843–|
|Adéle de Vinoy, HL||rue de Trois Bornes 15||metal pipes|
|13||Hector Ledru, Cheret et Cie||1 Mar 1845–|
1 Jun 1847
|HL, Louis Cheret, AdV(?)||rue de Trois Bornes 15||pipes|
|14||Robin et Cie||1 Jun 1847–|
|HL, AdV, Pierre Robin Bernard Robin||rue d'Angouleme-du-Temple 42||pipes|
|15||Ledru, Robin et Cie||1 Jun 1846–|
|HL, AdV, Pierre Robin Bernard Robin||rue d'Angouleme-du-Temple 42||pipes|
|16||Guillard, Ledru et Cie||9 Jul 1857–|
3 Nov 1857
|Marie-Joseph Gulliard, HL, Jules Cropin, Théodule Charles Launay|
(Société du Carburateur Launay)
|rue de Rivoli 164||heaters|
|17||Vaudore, Ledru et Cie||3 Nov 1857–||Alexandre François Vaudore, HL, Jules Cropin, Théodule Charles Launay(Société du Carburateur Launay)||rue Mazarine 42||heaters|
|18||Hector Ledru, de Bournonville & Cie||1856–1867||Société des Chauffages par les Calorifères|
HL, Achille Louis Albert de Bournonville
|19||Hector Ledru, de Bournonville & Cie||1868–1872||HL, Louis Albert de Bournonville||Paquis (Geneva)||heaters|
|20||Halley et Cie||HL||heaters|
Abbreviations: AdV–Adéle de Vinoy/Ledru; HL–Hector Ledru.
© 2017 Walter de Gruyter GmbH, Berlin/Boston