Windmills in Eighteenth Century Finland, Kirsti Horn (2019)

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Old maps and lost windmills at a UNESCO Heritage site together with an astonishing find of some twenty 18th century vernacular mills are presented in this paper. It is published here with permission from the President of The International Molinological Society, Willem van Bergen. See also the presentation Eighteenth Century Windmills in SW–Finland given at TIMS Berlin symposium in August 2019. This paper has been translated into Finnish.


This study looks at the mills and events of the 18th century in the eastern parts of Sweden through firstly the number of windmills in three towns of present–day Finland; secondly the designs for the windmills on the fortress of Suomenlinna; and thirdly the surviving windmills of that time.

The pictorial evidence of earlier mills is scarce and the builders of the vernacular mills remain unknown in Finland. The written evidence is limited to church books and mill tax accounts that were kept ever since 1585. But many records have disappeared due to wars and fires. It is however, possible to construct a reliable picture of what mills looked like at the northern edge of viable agriculture two to three hundred years ago.

Keywords: windmills, built heritage, Finland, Enlightenment

1. Introduction

Figure 1: Map of Finland with the places that appear in the text.

1.1 Finland?

The time of Swedish reign over present day Finland lasted from the late 13th century until 1809 when Russia took over. The concept of Finland and Finns as a nation developed during the 19th century, and independence was gained in 1917.

As an inheritance from the early times we are still a bilingual country today with a small Swedish speaking minority. When studying the mill database you will notice that the Finnish mills are called either kvarn (Swe.) or mylly (Fin.) according to the language of the region they stand in.

1.2 The Greater Wrath and other hardships

The 18th century was a time of unrest in Sweden. The kingdom lost its status as a superpower in The Great Northern War (1700–21) and what remained was a u–shaped kingdom east and west of the Gulf of Bothnia: Sweden in the west and Finland in the east more or less in the shape they are still today. In the following, a short answer to why there are so very few old buildings in Finland.

First of all: Finland has always been very sparsely populated. In the early 18th century the population decreased from half a million to some 350000 people—and even today we are no more than 5,5 million.
Secondly: Finland served as battle ground between Swedish and Russian forces in four wars during the 18th century.

The conflict between Peter the Great and king Karl XII resulted in great losses of Swedish land area i.e. the Baltic countries, Ingria and areas in S–E Finland west of the new city, St. Petersburg. It also meant utter misery for the peoples in the conflict areas. In Finland this period of history is called The Greater Wrath because it was really a ruthless invasion and plundering by the Russian army and navy of the eastern provinces of Sweden in the years between 1710 and –21. Finland was left to fend for itself after Peter the Great had defeated the Swedish forces in the battle of Poltava in Ukraine (1709). He then started to attack Sweden via Finland while the Swedish army was busy in Norway. Since not much of the built environment was left standing in this ransacking by the Russian army it took several decades for the Finnish population and economy to recover after peace was made. No research has been done concerning the fate of the windmills that are known to have existed before The Greater Wrath. However, against the odds two of them have made it to the present day.

Another Russian invasion, The Lesser Wrath, occurred some 20 years later, lasted only two years and had less disastrous consequences. The Swedish army was quite defenseless against the invaders.

In order to guard the Finnish Gulf and defend the southern coast of Finland the construction of Suomenlinna (Fin.) or Sveaborg (Swe.), a large fortress and military base, was started on the islands outside Helsinki in 1748. It was the biggest building project in Europe at the time, today a Unesco world heritage site. The first smock mill in Finland crowned the northern cliff of one of the islands providing the military base and its builders with meal and sawn timber, and by pumping the water out of the navy dry dock.

Even the enlightened king Gustav the III of Sweden wanted to have a go at the Russian Empire by starting The Russian War 1788–90 with the aim to regain the territories that had been lost in 1721 along the south–eastern border. The Swedish army was still not successful.

The Finnish war in the years 1808–09 put an end to the Swedish reign over Finland. As the Russians marched in the Swedish army retreated before them. To start with, the mighty fort of Suomenlinna was left to the enemy, and in the end, everything east of the present–day border between Sweden and Finland was handed over!

2. About the number of Finnish windmills in the past and today

Windmills were counted in hundreds around Turku by the year 1700, and altogether there were some 1000 within the boundaries of present–day Finland at that time, mostly in the SW corner and in Ostrobothnia further up the western coast. Bearing in mind the tumult of the early 18th century it is justified to assume that many mills were lost and that the number did not start growing until the time of the Enlightenment in the second half of the century. We do not have figures for this period of time but we do know that around 1830 the number was well over 5000. Also, it has been assumed that there were up to 20000 windmills at the end of the 19th century although the official records, i.e. the reports about the state of the provinces collected by their governors, add up to only half of that (which is rather a lot anyhow).

There have been attempts to count the surviving windmills in the 20th century but the latest count by Leo van der Drift is the most ambitious one. 701 mills have been found so far (April 2019), counting wooden post-, hollow post– and smock mills, American wind pumps, halves of hollow post mills, abandoned windmills, replicas and ruins. Of these some six hundred are traditional wooden windmills that are more or less intact although not workable, except for a handful. A few more mills are expected to be found still when detailed surveying is continued off the beaten tracks.

3. Mills of Finland in the eighteenth century as seen on maps and illustrations

Because no technical drawings exist except for the two mills on Suomenlinna, the only way to find out about the 18th century mills and milling activity in Finland is via contemporary maps and illustrations. The interior of the land had few towns and few inhabitants and towards the eastern border there was a vast wilderness. Therefore, the presented examples of this study are from three towns along the western coast: Tornio—whose attraction is the midnight sun, Uusikaupunki—best known for being the scene for the 1721 peace treaty and Turku—the capital of Finland. New fashions and inventions arrived from the west via the coastal communities, and the Swedish influence was strong here. The skilled shipbuilders, carpenters and joiners on the southwestern and western coast must have played an important role in the introduction of windmill technology in these hinterlands. The close western contacts explain why the majority of Finnish vernacular mills are similar to those that can be found in the northern countries around the Baltic Sea who also were part of the Swedish empire before the Great Nordic War.

3.1. Tornio

A view of Tornio dated 1796 shows at least one post mill with four sails on the eastern side of the river.

In 1715 the Russians burnt this town of a few hundred inhabitants but already in 1736 there were 10 mills according to a map by the scientists Outhier and de Maupertuis who spent quite some time there measuring the shape of the Earth.

Figure 2: Tornio, Engraving by Erik Dahlberg 1796.

Figure 2.1: Detail of figure 2.

Figure 3: ‘Viewing the Midnight Sun’ by Matthew Consett, 1789.

Matthew Consett recorded two of the mills in Tornio together with his friends who had travelled all that way to experience the nightless night in 1789. The post mills did not develop any further from this illustration during the 19th century when they were built in thousands all over the country. Consett presented the mill too small in proportion to the people around it but otherwise it seems true to the type of mill that has survived in the western parts of the country. It seems to have a trestle of log construction, probably a timber frame with weather boarding, a thin roof made of boards resting on purlins, a sack hoist and sails unlike those that are found in the region today but identical to those in contemporary illustrations of mills in Uusikaupunki and Turku which are presented below.

3.2. Uusikaupunki or Nystad (Swe.)

On a map presenting Uusikaupunki in 1721, around the time of the peace negotiations, 9 mill symbols can be distinguished, three of which are probably ruins. The presentation is too unclear for any conclusions to be made as to their overall shape. At the time there were only 300 Finns but a whole lot of Russian soldiers and a number of participants to the negotiations in the town. Kangas (1996).

Figure 4: Detail of map of Uusikaupunki dated 1753.

The above detail of a later map dated 1753—GRUND RITNING öfwer Sjö Staden NYSTAD—shows four of the sixteen post mills in Uusikaupunki. No details can be perceived in the schematic presentation of similar windmills as in Tornio except for the straight narrow shape of the sails and the pyramidical shape of the trestles. At the time there were no more than 500 inhabitants in Uusikaupunki.

3.3. Turku or Åbo (Swe.)

In the early 18th century there might have been a few thousand, perhaps even five thousand, inhabitants in Turku but a famine, a plague and the Russian invasion reduced the number to just over one thousand in 1721.
A map dated 1709—Delineation öfver Åbo Stapel Stad—shows that there were 51 post mills with tapering sails on the hills within the city boundaries. Kostet (2009).

Figure 5: Detail of Charta öfver Stapel Staden Åbo, 1756.

Figure 6: Detail of Charta öfver ÅBO STAD 1808 depicts post mills, each with the characteristic details.

Several maps of Turku from the 1750’s onwards have survived in the archives. 75 post mills are depicted on a map from 1756, called Charta öfver Stapel Staden Åbo. A close view on a group of these mills reveals a type very similar to those in Tornio in terms of overall shape and sails. Only the trestles might be different, i. e. made of quarter bars with logs underneath. (Figure 5)

A later map, Charta öfver ÅBO STAD 1808 by Joh. Tillberg has less windmills (69) although—or rather because the number of inhabitants in the city had grown to 11000 by then. (Figure 6) In fact, most mills were then built beyond the town boundaries, and there were hundreds of them before the great fire of Turku in 1827 according to a newspaper article (Sanomia Turusta, 20.1.1852).

3.4. Mills at manor houses

Some illustrations of post mills appear in late 18th century views of manor houses but possible evidence of early hollow post mills and smock mills before the first decade of the 19th century are not to be found in the digital archives of Finland. It is unlikely that there are more than a few—if any—surviving examples and judging from no attained pictorial evidence hardly any did exist in 18th century Finland. Yet, Auvo Hirsjärvi and Rex Wailes claim in their booklet on smock mills in Finland that “… it is almost certain that hollow–post and smock mills were introduced into Finland during the last half of the eighteenth century.” Hirsjärvi and Wailes (1970–71) Indeed, a few of these can be found in the illustrations by Eric Dahlberg of Swedish towns already in the late 17th and early 18th centuries. Then, why not in Finland?

4. The first smock mill in Finland

Five mills can be distinguished in the misty landscape painting View of Suomenlinna from the shores of Helsinki by M. N. Vorobjov: one tall mill and three smaller mills on the Suomenlinna fortification islands and most probably a smock mill on the small island to the left.

Figure 7: ‘View of Suomenlinna from the shores of Helsinki’ in 1809 by M. N. Vorobjov.

4.1 Daniel af Thunberg at Suomenlinna or Sveaborg (Swe.)

Daniel af Thunberg (1712–1788) studied theology but made a career in civil engineering, particularly in inventive design and building of waterways. When the grand project of Suomenlinna was started in 1748 he was appointed as site manager and millwright. His contribution was the design of the dry dock—one of the oldest in the world which is still in use—together with a windmill of overwhelming dimensions that pumped the water out of the dock, sawed the timbers for the ship yard and ground flour, all at the same time.

Swedish engineers made study trips to Holland but it seems Thunberg did not have the opportunity. However, he worked at Laboratorium mechanicum with Christoffer Polhem, Father of Swedish mechanics. This is where he must have learnt about the large industrial mills of Holland and perhaps copied one of those or transformed one for the special purposes on Suomenlinna. The pump that Thunberg attached to his windmill is of the type that was used in Swedish mines at the time.

The mill was moved to another island of the fortification in 1783 and finally pulled down in the 1850´s. Exact drawings for the rebuilding are to be found in the Military Archive of Stockholm while the originals by Thunberg are gone. However, there was a young assistant on the Suomenlinna building site, Adolf Eric Geete who kept a sketch book where he recorded the works and the mill, in its original settings. The sketches which still survive in the archive on Suomenlinna include also copies of a design for a post mill and a watermill by Thunberg. These are the only (!) technical drawings of windmills that we know of in Finland except for those in a book by Samuel Roos (1851) describing certain functional aspects of wind and water mills.

Figure 8: Detail of a drawing of Thunberg’s mill in its original setting with the pump, 1751.

Figure 9: Detail of a drawing for the rebuilding of the mill in 1783 by Nordenkreuz.

Figure 10: Post mill sections, design by Thunberg, copied by Adolf Geete.

The height of Thunberg’s smock mill from top of masonry base structure (storage) to top of cap is ~22m, the sail span ~25m and the width of the base ~13m. (Scale 10 aln = 5,9m.) The three–storey post mill measures some 12m in height and has a sail span of some 18m. The average farm mill was less than half of this size.

Technical drawings were not actually necessary for the sort of small post mills that are the predominant type in Finland. A small wooden mill could easily be taken apart and transported by boat across the Gulf of Bothnia to serve as a model for local builders. It is also likely that millwrights came for visits to teach the locals or set up a business. This is however, academic speculation as documented evidence is very hard to find.

5. What did the Finns grind in their mills in the eighteenth century?

Practically all the windmills of Finland were small farm mills built for making flour. The modest diet of the average Finn consisted of root crops, milk products, fish, game, some vegetables and berries in addition to cereals. Barley was the most important food grain ever since 4000 B.C. and still throughout the 18th century it formed the staple diet together with rye which has been grown in Finland since 500 B.C. In addition, buckwheat, wheat and oats were grown in small quantities.

6. Mill–related developments during the Age of the Enlightenment in Sweden

The second half of the 18th century was a very much more positive time than the beginning although two more Swedish wars were fought on Finnish ground and in the coastal waters of the Gulf of Finland. It was a busy time of reconstruction and development, also the time of the Enlightenment and early industrialism in Sweden. In addition, an influx of Central European people and ideas enlivened even the eastern hinterlands. In Stockholm King Gustav III of Sweden (rule 1771–92) surrounded himself with theatre, music, silks and Classical architecture. On the other hand, great effort was invested in the development of agriculture and early industrialism along with the study and implementation of natural sciences during his rule. Even Prince Gustaf Adolf was introduced to country life and agriculture from an early age. In his ABC–book Q is the letter for qvarn.

Figure 11: Detail from Prince Gustaf Adolf’s ABC–book. The lesson for the letter Q: “A mill placed on a hill, gets active by the wind. Make use of your position in order to be of service.”

Figure 12: One of many carvings showing the new model of a plough on the stone casing of a private 18th century type post mill.

The Enlightenment brought a welcome development in practical terms to Swedish farmers, small scale industry as well as to building technique. New methods for cultivating the land were developed at the Swedish Academy of Sciences, and locally at the University of Turku. The ideas were spread throughout the kingdom by officials and the rural clergy who cultivated their parsonages to be models for the peasantry and preached about better cattle breeding, clearing of forests and draining of marshes into arable land and other practical aspects of more efficient farming. The northern and eastern provinces of Sweden were inhabited and the aim was to make the population grow in order to regain the lost status of a superpower. Also, efforts were made to spread the knowledge of mills and new designs for ploughs. This can be witnessed in carvings on the walls of several of the oldest windmills in SW–Finland.

Up to 150000 barrels of grain were exported annually from Finland to Sweden during the last decades of the 18th century although in terms of agriculture, the climate is not particularly favorable, and the development towards efficiency and expansion of field area had been relatively slow among the peasantry. Klinge (2006) Quite naturally the growing crops led to greater milling activity and a need for a growing number of windmills, too. It is worth noting that Finland of today is nearly as large as Germany but even now, only 7 % of the land is arable, 78 % is forested, 10 % lakes and 5 % urban.

7. Surviving eighteenth century windmills in Finland

The oldest two surviving windmills in Finland date back to the early years of the Great Wrath. One is on Lumparland, the Åland Islands (1700–1720) and the other on the Isle of Hailuoto, in the northern end of the Gulf of Bothnia (1712). There are a few surviving later 18th century windmills in the central parts of the country, too—no systematic record exists—but the majority are situated in the South–West. More of these ancient monuments are expected to be found once the detailed surveying extends further north.

A group of 18th century post mills were visited in the south–eastern coastal areas in the summer of 2017. Sixteen of these carry a date inscribed on the post, crown tree or the downstairs wall. (Another two with a date are early 19th c.; one lacks the date but is known to be 18th c.; another six are so strikingly similar that they are likely to be contemporary with the ones that still carry a date).

Similarity in detail and structure is the common denominator of these 25 windmills. Although all post mills look very much alike and have rather uniform dimensions in this region, later mills have greater variation in their details than these do. There are several identical features in all these mills that arise the question of who their builders might have been. Clearly, these are the Mercedes Benzes among their contemporary mills: they were built to last, they were made of carefully chosen material and most of them were in use for nearly two centuries. Generally, they have also been well looked after. Except for one they contain a more or less complete machinery. Their known dates range from 1732 to 1806. They are situated in a fairly limited area of some 45 by 45 km. Several have been moved within this area but ten mills are said to stand on their original site.

A windmill was considered a personal belonging. It followed the owner in marriage or when a farm was divided between inheritors. It could also be sold. Hence, most surviving mills have been moved several times in their history and every move has brought changes in the structure. Against this back ground it is remarkable that there are very old mills that still stand on their original site and carry the details of the 18th century.

Apart from the tradition to take one’s mill along to a new home there have been two waves of moving them. The first occurred when they became redundant in more developed areas and were bought up by farmers in distant regions that lacked electricity. The second wave occurred after the second World War when they became redundant everywhere and some of the best examples were rescued into open air museums.

Figures 13: Post mill, 1741, private.

Figure 14: Post mill, 1760, private.

Unique features in the old post mills of SW–Finland:

  • An extra massive frame supporting the stones with one corner cut/rounded to give easier access from the stairs to the upper floor: 25 of 25 mills. (Figures 15 and 16)
  • The upper floor in front of the stones rests on the stone frame instead of crown tree: 23 of 25 mills. (Figures 15 and 16)
  • A hole in the crown tree for injecting grease into the bearing. 16 of 25 mills (Figures 15 and 16)
  • Carved handles on machinery or porch: 6 of 25 mills. (Figures 17 and 23)
  • Carved dates, drawings, symbols, miller´s book keeping…16 of 25 with date, 9 with figures, summa 18 of 25 with carvings (Figures 12 and 18)

Surviving original parts that are usually lost when a mill is moved:

  • Wooden bearing under the floor joists: 10 of 25 mills (all on their original site). This functional detail has usually gone missing when mills have been moved. (Figure 19)
  • Original weather boarding: 4 mills + 1 where the owner has kept samples
  • Carved ridgepole: 3 mills + 1 where the owner has kept a section (Figure 22)

Specific old features:

  • Octagonal post: 8 mills.
  • Corner braces of naturally bent wood in the timber frame: 3 mills. (Figure 21)
  • Naturally bent wood as legs for hoppers: 5 mills. (Figures 15 and 23)
  • Stairs made of a single carved log: 2 mills. (Figure 20)

Figure 15.

Figure 16.

Figure 17.

Figure 18.

Figure 19.

Figure 20.

Figure 21.

Figure 22.

Figure 23.


The greatest spectacle in terms of technical innovation in 18th century Finland was the dry dock and enormous Dutch style smock mill of the Suomenlinna fort and military base, completed already during the years 1751–56.

Maps and illustrations suggest that throughout the century, all vernacular mills were small post mills.

They are all depicted with four symmetrical sails with straight sides which widen outwards. The fact entails that all the other types of sails of Finnish windmills are of the 19th century and particularly, that the wide paddle shapes of sails in the eastern and central parts of the country originate in Russia.

The windmills in the northern parts of the Turku archipelago and the corresponding coastal region are strikingly uniform. As we know nothing about the builders of these mills only detailed studies of parts of the machinery and certain structural details of the millhouses might reveal traces of individual millwrights and rather inconspicuous development or variation in the design during the 70 years when these mills were built.

The greatest surprise is the discovery that so many post mills of the eighteenth century have survived despite the politically trying times and the wear and tear of both use and climate.


Chapter 3.1

Figure 2 and 2.1: Accessed at http://urn.fi/URN:NBN:fi:jyu-201008112429

Map by Outhier and de Maupertuis, Bibliothèque nationale de France, can be accessed at http://urn.fi/URN:NBN:fi:jyu-201003301366

Figure 3: accessed at http://www.doria.fi/handle/10024/33389, National Library of Finland

Chapter 3.2

T. Kangas, Uudenkaupungin siunattu rauha, 1996, ISBN 952-90-7798-X

Figure 4: Illustration in the thesis by Ephraim Hoeckert, drawn by Henrik Seeliger, University of Turku 1753

Chapter 3.3

J. Kostet, Cartographia Urbis Aboensis, 2009, ISBN: 978-952-5217-83-4

Figure 5: Accessed at http://digi.narc.fi/digi/view.ka?kuid=33618110

Figure 6: Accessed at http://digi.narc.fi/digi/view.ka?kuid=33618118

Chapter 3.4

A. Hirsjärvi and R. Wailes, Finnish Mills Part II Mamsel or Smock Mills, The Newcomen Society, London 1970–71

Chapter 4

Figure 7: Helsinki city museum. HKMS000005_000007k8

Chapter 4.2

S. Roos, Muutamia mieleen pantavia Asioita myllyn rakentajoille Suomessa, Turku 1851

Figure 8: Utländska stads- och fästningsplaner, Sveaborg Vargö SE/KrA/0406/12/042/C/031 (1751) bildid: K0017883_00001 (Military archive, Stockholm)

Figure 9: Utländska stads- och fästningsplaner, Sveaborg, Väster Svartö, SE/KrA/0406/12/042/F/026 (1783), bildid: K0018505_00001(Military archive, Stockholm)

Figure 10: Original in the archive of Ehrensvärd sällskapet rf. Suomenlinna B 40, Helsinki; Photo at Millsarchive REXW-FIN-526-02

Chapter 6

M. Klinge, Iisalmen ruhtinaskunta, Keuruu 2006, SKS ISBN 951-746-841-5

Figure 11: M. Klinge, Iisalmen ruhtinaskunta, p. 166

Figures 12–23: Views of 11 private mills and their details. Photos © Kirsti Horn