Carl Arnold Séquin-Bronner
and Hilarius Knobel Jr.
One prominent industrial architect at the end of the 19th century was Carl Arnold Séquin-Bronner. By education an engineer and by profession an inventor and entrepreneur, he became an important designer and a pioneer of industrial architecture – but has only been known for the last several years. Although specialised scholars have repeatedly highlighted his extensive body of work and his significance for architectural history,  the extent of his work as yet remains unclear, as no monograph dedicated to him has yet been published.
During research that I conducted on factory architecture in Zürich as part of my degree work,  Séquin came to fascinate me more and more as the architect behind some of the most significant buildings and structures in Zurich. Fortunately, I found his Nachlass in the gta Archive at ETH Zurich, which – despite being incomplete and not yet processed – nonetheless represents an extensive and important resource. Although there are no lists of plans or anything like that among his papers, it was possible to form at least a rudimentary picture of his internationally scattered body of work.
The most significant source of information on the biography of Carl Arnold Séquin-Bronner is the Schweizerische Bauzeitung, a widely distributed professional journal that regularly published obituaries on important figures in architecture and construction. After Séquin died unexpectedly on 25 November 1899 after a short illness, the journal wrote: ‘ Our colleague Séquin was one of the most significant and one of the most widely employed experts on industrial facilities on the European continent and the number of industrial works that in the past two decades he either designed or worked on down to the most minute detail is surprisingly large . […] His work is found in an area that stretches from the south of Italy up to Finland. […] More than 250 manufacturing plants at home and abroad […] will in the future bear witness to the achievements of this widely esteemed and popular man .’ 
Carl Arnold Séquin-Bronner was born on 25 January 1845 in Uznach, a small village near Lake Zurich. In 1863, he enrolled at the age of eighteen in the Polytechnic School in Zurich, the predecessor of today’s ETH, in the department of machine technology. However, he left university prematurely, evidently because of the overly lax approach he took to his studies. Instead he furthered his education through practical training, first by working for the engineering firm of Daněk & Co. in the district of Karlín in Prague and then, after returning to Switzerland, at the engineering works of Caspar Honegger in Rüti. Within the company, Séquin was mainly engaged in the assembly and installation of the power looms and weaving machinery, and with the spatial arrangements required to accommodate them. In order to provide customers more comprehensive services the company also began offering consultation on selecting the right architectural structure to house their products.
Séquin recognised the market niche that he could fill. In 1879, the year when he married Georgine Laura Bronner, he opened his own office in Rüti and named it ‘C. Séquin-Bronner, Civilingenieur’. He was soon advertising his services as a company specialising in ‘modern factory construction’ and offered a range of different factory types. Séquin supplied both complete buildings for immediate use and project blueprints for local contractors. According to the office letterhead, there existed a branch office in Vienna, and another branch in Prague, thus in important centres of growing industrialisation in that era.
The aforementioned obituary for Séquin in theSchweizerische Bauzeitung cites ‘ a series of important innovations […] especially in roof structures, which quickly won him a well-earned reputation far beyond the borders of our land .’ The office’s advertisements in the professional press promoted a new construction system of a factory shed with a flat cement-wood roof, which was drained through the hollow cast-iron support columns and admitted light through the saddle skylights, which were double-glazed without putty. The factory roofs would then require almost no maintenance.4 The engineer Ludwig Utz, a professor at the Institute for the Textile Industry in Vienna, commented on this design: ‘ The best ones, which can be directly described as modern facilities, are the saddle skylights by the civil engineer C. Séquin-Bronner in Rüti, who has extensive experience in factory construction. […] They were indeed revolutionary and were a massive success.’ 
After Séquin’s premature death, civil engineer Hilarius Knobel jr. (1854–1921), the former office manager, successfully led this much in demand büro under the name Séquin & Knobel and later, until it was dissolved in 1916, under his own name ‘H. Knobel’. 
It is generally known that the innovations that emerged in industrial construction during the 19th century had an influence on the development of modern architecture in the 20th century. And it is evident that thanks to the rapid economic changes and related financial pressures, architectural solutions were sought and found in factory construction that went beyond the framework of industrial production to expand and enrich the wider architectonic vocabulary. Frequently, eager engineers were the ones who – when planning and designing factory buildings – developed new building materials and structures, and these were then adopted by architects for different building contexts and assignments. As for the buildings Séquin created, many of them have vanished without their significance ever having been recognised. This makes it all the more urgent to show the influences and developmental links that connect industrial structures to modern architecture on an individual level through specific individuals and structures.
1 Hans Martin Gubler, Die Kunstdenkmäler des Kantons Zürich, vol. 3 (Die Bezirke Pfäffikon und Uster) (Basel: Gesellschaft für Schweizerische Kunstgeschichte, 1978), pp. 432–433, 363, 655, 670–671; idem, Die Kunstdenkmäler des Kantons Zürich, vol. 7 (Der Bezirk Winterthur: Südlicher Teil) (Basel: Gesellschaft für Schweizerische Kunstgeschichte, 1986), pp. 18–19, 81, 84–85, 304, 407–408. See also idem, ‘Ein Pionier des Fabrikbaus: Zur Geschichte der Familie Séquin und ihrer Villa in Rüti’, Heimatspiegel: Illustrierte Beilage des Zürcher Oberländers, no. 7 (July 1983), p. 50–55; Hans-Peter Bärtschi, Industrialisierung, Eisenbahnschlachten und Städtebau: Die Entwicklung des Zürcher Industrie- und Arbeiterstadtteils Aussersihl. Ein vergleichender Beitrag zur Architektur- und Technikgeschichte (Basel, Boston, Stuttgart: Birkhäuser Verlag, 1983), pp. 445, 463; Michael Hanak, ‘ Carl Arnold Séquin ’, in Historisches Lexikon der Schweiz, vol. 11 (Basel: Stiftung Historisches Lexikon der Schweiz, 2012); idem, ‘Carl Arnold Séquin-Bronner’, in Günter Meissner, Andreas Beyer, Bénédicte Savoy, and Wolf Tegethoff (eds.), Allgemeines Künstlerlexikon, vol. 103 (Seitz – Silvestre) (Berlin, De Gruyter, 2019).
2 Michael Hanak, Fabrikarchitektur in Zürich. Die Entstehung der Industrieareale 1890–1930 , PhD thesis, Kunstgeschichtliches Seminar, Universität Zürich, 1997.
3 ~, ‘ Karl Arnold Séquin-Bronner ’, Schweizerische Bauzeitung 34, no. 22 (2 December 1899), pp. 214–215.
4 ~, ‘Dachkonstruktion für Fabrikbauten’, Schweizerische Bauzeitung 41, no. 16 (18 April 1903), p. 178.
5 Ludwig Utz, ‘Moderne Fabriksanlagen mit besonderer Berücksichtigung der Textilindustrie’ , Wiener Bauindustrie-Zeitung 13, no. 48 (27 August 1896), pp. 595–597. See also Otto Johannsen, Handbuch der Baumwollspinnerei, Rohweissweberei und Fabrikanlagen, vol. 2 (Leipzig: B. F. Voigt, 1902), pp. 679–694.
6 Arnold Lassotta, Eine Musterspinnerei für die Herren Huesker: Séquin & Knobel – die Konkurrenz aus der Schweiz. in: Arnold Lassotta et al. (eds.), Cotton Mills for the Continent: Sidney Stott und der englische Spinnereibau in Münsterland und Twente (Essen: Klartext Verlag, 2005), pp. 116–124.