The Art of Survey of the Earth from Finnmark

Struve's geodetic arc was added to UNESCO’s list of the world’s natural and cultural heritage in 2005. The geodetic arc was measured from 1816 to 1852. It was the first accurate measurement of a long geodetic arc which made it possible to calculate the earth's size and shape. It was also the longest and northernmost geodetic arc in the 1800s. The co-operation between prominent surveyors, geodesists and monarchs characterised the story of this world heritage. Less well known is an account of the surveyors' seasonal fieldwork in West Finnmark from 1845 to 1850. What were the major challenges? How did they use the landscape of West Finnmark to measure a chain of triangles and a series of measurements from Hammerfest to the Black Sea?

The World Heritage Struve's geodetic arc was named after Fredrik Georg Wilhelm Struve (1793-1864), who was a professor of mathematics and astronomy in today's Tartu in Estonia. He was responsible for the triangulation in Livland, which was a part of Russia. In 1820 Struve put forward a suggestion to the authorities to carry out a chain of survey triangulation in the Baltic region. He argued that this work would have great scientific value and would also be important for mapping the country.

The military surveyor Carl Tenner was engaged in surveying work in Lithuania. He managed to combine the need for mapping and triangulation. Together he and Struve published the results of their investigations in 1832. At the same time the idea of an extended geodetic arc down to the Black Sea was beginning to take shape. Now it was a question of also persuading the authorities in Norway and Sweden.

In 1844 the Academy of Science in Stockholm received a request to join a Swedish-Norwegian project. Nils Haqvin Selander, who was the director of Stockholm Observatory, wrote a letter of recommendation to the authorities, as did Christopher Hansteen, director of the Observatory in Christiania. Nordkapp (the North Cape of Norway) was pointed out to be the northernmost end-point, and among the considerations discussed was where the greatest challenges would be, and which route should be chosen from Nordkapp to the Finnish border. After studying the maps of the area, Selander concluded that there were two possible routes, one via Porsangerfjord and one via Altafjord. He thought that the greatest challenges might the Swedish surveyors face in Muonio. Another problem would be the transport routes via the Alta River because many large areas of inner Finnmark were uninhabited with few people who could assist in transporting the expedition. In Norway they were more concerned by convincing the authorities that it was necessary to participate, and felt the challenges could be resolved by sending two competent people to do a reconnaissance of the terrain. On July 13th 1845, it was decided by a joint Swedish-Norwegian parliamentary committee that work on surveying the arc should begin in both countries. Thanks to this quick decision, less than a month later the expedition team was in Hammerfest.

The measuring of Struve's geodetic arc in Finnmark was Norway's first participation in an international scientific co-operative venture. Selander and Hansteen had the responsibility for the surveys in Sweden and Norway in 1846. Hansteen himself did not take part in the fieldwork. That was left to two army officers, Fredrik Klouman and Christopher A.B. Lundh. Both of them had specialised in surveying at the Military High School. Klouman learnt about Finnmark when he spent two seasons doing fieldwork there in 1840 and 1841 for NGO, Norway's Geographic Survey. Their job was to reconnoitre the triangle points, select station points for surveying the arc and locate suitable sites for baseline measuring (initial measurement) and astronomic observations. Then they should come up with a recommendation of which station points could be used for the Norwegian part of the measured chain.

D.G. Lindhagen was a Swedish astronomer working in Struve's team in Poulkova. He participated in the summer of 1850, carrying out base line measuring and astronomic observations in Alta and in Hammerfest. His reports from 1850 in Norway and 1851 in Lappland are included as appendices in Struve's publications. His associate, Lysander, assisted him with the fieldwork that season. 

Although the sources do not name those who assisted the expeditions, the four seasons spent in an area with poor transport roads could not been carried out without considerable effort by local craftsmen, carriers, boat masters, cairn builders, and local people with an extensive knowledge of the area.

The following presentation will concentrate on the first reconnaissance trip in 1845 and the survey work in 1846 and 1847, along with Klouman's and Lindhagen's measuring of the base line in Alta and their astronomic observations in Hammmerfest in 1850. The content of the source is partly difficult, because diaries and reports concentrate largely on measurement results. The purpose of the presentation is to reconstruct the course of events and raise some questions. How did they organise the work? Which travel routes and methods were chosen? And what were their greatest challenges? But before we look in more depth into the expeditions in Finnmark, we need to say something about their method and what kind of climatic challenges they faced.

Method

The method is based on the simple principle that if you know the length of one side and two angles of a triangle, you can work out the lengths of the other two sides. Then a series of triangles can be established. The chain in Norway consisted of 15 station points on the tops of mountains. Signals were built and established on mountaintops from Tyven to the Finnish border. Signals are physical constructions that can be circular or square cairns, or wooden towers. In Finnmark they built stone cairns on mountaintops which functioned as trigonometric points from which a survey of triangulation could be taken. The plan was to build cairns with loose rocks, being the only material readily available. The signals were to be two metres tall, which was the standard dimension. They were to be hollow and circular stone cairns, with an iron bolt in the centre. In the hollow room the signal would be carefully placed and adjusted. It was mounted on a cylindrical log 10 cm in diameter and 3.5 metres tall. It was supported by three logs and a cairn. The signal cairns were half barrels which were partly painted white, with a diameter of roughly 92 cm (3ft) and a height of 61 cm (2ft). But not all of the signals built of the available rocks in the area were equally solid.

Only five years after the signals were built, it was reported that they on Haldde and Luvddiidčohkka had been badly damaged.

In 1845 and 1846 Lundh was busy measuring barometric altitudes to determine height above sea level. Since air pressure decreases with height above sea level, by using a special formula it is possible to calculate how high up you are. For exact measurements this figure has to be corrected for air temperature and humidity. Several measurements were taken at two to three heights in the terrain at specific times of the day - early morning or afternoon. The figures for Alta were compared with the figures for Hammerfest on the same day, and all the measurements from inland stations were correspondingly compared with measurements taken at the Kåfjord observatory the same day.

When the station points were in place, the zenith measurements could start. This is a vertical angle measuring. The zenith is the point directly above the observer, i.e. +90 degree angle, and a zenith distance is the vertical angle between the direction to the zenith and the direction to a point aimed at. By measuring the zenith distance (vertical angle) between two end-points you can determine the difference in altitude between two points; this is called trigonometric altitude measuring. The instrument used in 1846 and illustrated below was a Repsold from the Royal Observatory in Christiania. The instrument could measure angles both horizontally and vertically, and carry out measurements in the opposite direction of the rotation directions. 

When the angle measurements of the 15 station points which made up a network of triangles were completed in 1847, the network's scale needed to be decided by establishing a length basis. The baseline was established in Alta. It had two end-points, A and B. The easternmost point was in Elvebakken and the westernmost in Bukta. Both points were marked with granite blocks dug into the ground which were visible 20 cm above the surface. Into each block they drilled a cylindrical hole for an iron bolt to be encased in lead. Until the middle of 1800 they used measuring rods made of wood. They were 2 toisers, or about 4 metres long. In all, the base line was 577 rod lengths or (1154 toisers) 2251 metres. To transfer the measured length from the initial measurement to the survey of triangulation net itself, they established a so-called extended triangulation net. The net consisted of 10 points which formed triangles of increasing sizes. The baseline constituted one of the sides in the smallest triangle, while one of the sides in the largest triangle was identical with one side in the geodetic arc net. In this way they were able to calculate the length of one side in the geodetic arc net, and with that length and the other angle measurement they could work out the length of all the sides which made up the geodetic arc.

When the size and shape of the triangulation chain was determined, they had to find out the network's real placement on the earth's surface. This was done by astronomic observations at Fuglenes. The astronomic measuring instruments measured the exact time when a star crossed the geodetic of the observed point, while the latitude itself was measured by finding the distance between two different pairs of stars (see www.stuve.no to read more about the method).

Climate

The "Little Ice Age" still ruled the country. Some researchers believe that it came to an end in about 1850; and others belive it came to an end as late as 1920. As systematic temperature measurements were not recorded before 1863, it is difficult to have an opinion on whether the weather was unusually cold during these summers. The written sources relating to Finnmark report poor harvests, the late arrival of spring, and early winters. Lundh's and Klouman's logbooks reports that there were high winds, mist and rain, and few summer days when the temperature rose to over 20°C. 

End-point at Nordkapp or Fuglenes?

Nordkapp was planned to be the northernmost end-point of Struve's geodetic arc. The reason it was rejected is usually explained by the fact that it was susceptible to fog and poor weather conditions. There are no records of this in Kouman's and Lundh's logbooks. The proof of the first intended chain of survey triangulation in Finnmark is an old sketch in the Mapping Authority's archives (see figure 1). The triangles with dotted lines relate to the northernmost triangles. For the first established and northernmost triangle, a line has been drawn between Kvalvik Mountain (the mainland side of Havøya) – Kvalfjord Mountain (Kvaløya) – Kjøtvikfjellet (Sørøya). In a letter from Hammerfest to the Norwegian Geographic Survey (NGO), 31st July 1845, the researchers felt that Havøya was the most suitable place for observations. On Havøya they had visited the merchant Ullich, who could provide them with everything they needed to build a cabin for their astronomic measurements and observations, and for their accommodation. In the course of the summer of 1845, Lundh carried out barometric measurements at fixed places along the coast for the intended chain of survey triangulation, with Nordkapp as the end-point. The actual time when they rejected Havøysund as the astronomic station and Nordkapp as the end-point of the geodetic arc is therefore somewhat unclear. Was it because of the weather conditions in 1845 or the drawn-out winter of 1846 which forced them to change their plans? The late spring of 1846 delayed their work by almost a month.

1845

When they came to Hammerfest on July 9th 1845 on the steamship "Prins Gustav," they did not disembark. Instead they continued on to Nordkapp. They explained that this would give them a better impression of the terrain than a map. From there they went straight to Bossekop where the old charting boat "Elida" had been hired. Then they went north again. On July 14th they passed Hammerfest, but before passing Kvaløya they encountered a storm and ran aground. The ship was damaged and needed repairs, but none of the instruments were damaged. They didn't have time to wait, and fortunately were able to hire another vessel "Ormen." The mishap had only delayed them for three days, but time was short. When the task was completed they were to meet their Swedish colleagues Selander and Lilliehöök in Kautokeino. 

The logbook from the barometric measurements in 1845 reveal the route they chose. The plan was to use three weeks sailing from the coast to the head of Altafjord, but instead it took five weeks from their arrival in Finnmark until measurements were taken in Alta. They had obviously used two of these weeks to plan the work.

The route went from island to island along the coast to the mainland and Alta, and from there on to Karesuando. They have not given any reason for the options they chose, nor do the sources mention how much equipment they had or how it was transported from Alta.

A hundred years later, the surveyor Axel Printz in his book "A surveyor's life in the midnight sun," described how they found their way from Alta to Kautokeino: "We took along with us: Solid, double house-tents, one for the surveyor, one for the assistants, one for the horseman, and one for cooking and dining. We also had a fully equipped expedition of instruments, clothes and bedlinen, kitchenware, saucepans and more. Something  was transported on tow, and something in panniers on the horses." Th. Bang recounts in his book "A surveyor's life in Finnmark" from 1873 that they had their regular assistants, and that the chief of police had provided eight "Lapps" for the surveying guides and woodsmen.

We therefore have to assume that there were a considerable number of people sailing on board "Ellida." The same would also be the case for the journey onward to Karesuando. The route from the coast to the head of the fjord was as follows:

23rd July to Havøya.

31st July to Hammerfest.

2nd August to Sørøya and Slettnesfjorden.

4th August to Seiland, Skreifjorden Jedki.

8th August to Stjernøya, Store Kjerringfjord and Kjerringfjell. 

14th August to Bossekop and Komsa.

16th August to Kåfjord.

17th August to Haldde.

That summer the route did not go via Alta River, and probably not via KautokeinoGuovdageaineatnu River either, which Selander had recommended in 1844. They must have preferred packhorses, carriers and local guides. Their route probably went along the ridges from Vuoskolvarri just south of Eiby on 25th August, to Nuhpi on 28th August and Caravarri on 30th August. Which route they took further on from Caravarri is purely a matter of guesswork. If they chose to go due east they would avoid wet boglands before they came to Bingis Biggeluobbal mountain lodge.

They could also have gone in the direction of Gievdneguoikka and be transported from there to Kautokeino by river boat. Instead of taking the river route they may have followed the ridges and used pack horses. That would mean east along the river to Kautokeino, where they arrived on 3rd September.

On 7th September measurements were taken at Bealjasvarri and on the 8th at Adjit. As was the case with Leoni d'Aunet seven years earlier (La Recherche expedition), their travel route may have gone via Kautokeino River towards Galanito before they crossed a large area of bogland towards Syvæjævri. Measurements were taken on 11th September at Maanselkæ "on the north side of the ridge, the borderline between the parish of Kautokeino and Palljokki shire under the benefice of Muonioiska in Russian Finland."  New measurements were taken the next day at "Aitama" and Karesuando.

On 18th August 1845 Klouman and Lundh sent a message from Bossekop to The Norwegian Geographical Survey (NGO). In the letter they related that they had corresponded with the Swedish surveyors Selander and Lillehöök (letter of 3rd July 1845) and had been informed that the Swedes had completed the survey of the chain of triangels from Pathaware to Karesuando, and they had selected some points which could unite the Norwegian and Swedish chain of triangles. What now remained was to investigate "Kolare Øen" for initial measurements. Lundh and Klouman also said in the same letter that they would continue their journey to Kautokeino the next day.

In a later letter (21st August 1845) sent from Kautokeino, Selander and Lilliehöök recommended that Klouman and Lundh should use Bealjasvarri and Adjit as common points for the chain of survey triangels of both countries. They also recommended that the Norwegian surveyors should contact the resident Sami community to be directed to the points, and that they could stay at the schoolmasters house.

The Swedish and Norwegian surveyors had planned to meet in Kautokeino, but this didn't happen. Three days were lost due to the grounding of "Ellida." The bad summer weather, the terrain and the distances in West Finnmark caused further delays. The expeditions of 1845 gave the Norwegian surveyors valuable knowledge about the area they were to work in during the coming fieldwork seasons.

1846

On 27th May the following year, Klouman and Lundh returned to Finnmark and Bossekop. In a letter to the the management of Norway's Mapping Authority they pointed out that the time was too early in the year: "It has been a drawn-out winter and the snow is still lying longer, especially out on the coast than it is here in Alta. The late winter has meant that only a few of our signals have been raised. The snow is now so wet that no man is able to get up to the mountains."

Fieldwork in 1846 started with a long late winter, and a minor accident with a barometer which was broken when they landed in Bossekop. Despite the offer to borrow an instrument from director Thomas in Kåfjord, they asked director Vibe in the Mapping Authority to have an instrument-maker to pack an instrument so that it could withstand the sea journey north to Bossekop. They had also hired the "Ellida" for the season, along with an able seaman from Tromsø.

What Klouman and Lundh spent their time doing between 27th May and 27th June is not clear from letters and logbooks that have been studied.  

My suggestion is that they used the time to prepare the expedition and hire people for signal building and transport. The aim was amongst other things to carry out measurements of angles from the 3 northernmost to the 7 southernmost stations.

The fieldwork season continued with Lundh taking barometric readings and Klouman, who had acquired a new theodolite - a Repsold, to take zenith measurements (angular distances). The first barometric readings were taken from the 2nd floor of shopkeeper Rostad's house, while the first zenith measurements were done from Tyven. The trade citizen Rostad is not mentioned elsewhere in Lundh's logbooks. But Iver Christian Rostad became a trade citizen in Hammerfest in 1836. He had managed a hostel/hotel there since 1838. It is probable that the expedition members lodged there during their stay in Hammerfest.

How long they stayed there is not recorded in the sources, but on 16th July they are in place in Alta. Here Lundh took barometric readings from the highest building in Eiby and the next readings near the birch woodlands at Vuosgolvarre Vuoskolvarre. Readings were then taken at Vuoldaivi before the expedition moved on to Caravarri via Njargajavri, where they established a camp two feet above the water from 21st to 24th July. It was mostly clear sky and windless weather at the camping site with temperatures around 10 - 13 C, but the temperature warmed up and from 24th to 29th July it was over 20 C.

After Spielgajavri they moved north via the Alta River and Lappajokka towards Avjovari where they established a camp from 5th to 30th July. The camping site was about 20 feet above the birch treeline on the south side of Avjovari.

This area must have been a huge challenge. To journey with packhorses through the landscape would be relatively easy as long as there was the possibility of following the low ridges, but the triangulation points had extensive marshlands between them. From the ridges they could observe the gentle landscape with yellow reed-beds surrounded by willow scrub and invisible swamps. But this gentle and simple lowland plain between the ridges was an optical illusion; it was more or less impassable. Traversing these areas with heavy loads was exhausting for men and packhorses. They could sink down to their knees and be stuck in a swamp. In that case the packs had to be downloaded and carried piece by piece until they found a more manageable route. Soggy areas and river beds covered with slippery grass were ideal conditions for millions of insects. When temperatures rose and the wind dropped, the most bloodthirsty insects would present a new challenge. 

From Avjovari they travelled southwards again towards Lappajokka. The camp site at Lappajokka was at the river's estuary. Again they went west back to Spielgavari from 3rd to 8th August. A fall in temperatures, fog, mist and rain, and little wind characterised their days here. At Kautokeino vicarage and church the weather was more or less the same, but with a few more hours of clear skies. They stayed there till 12th August, with short excursions to Bealjasvarri on 10th August and to Adjit on 12th August. The journey then went northwards via Caravarri 18th August and on to Vuolddejavri on 22nd August. They reached Nuhpealas on 25th August and then trekked eastwards to Lodiken Luvddiidčohkka where they set up camp at Holgajavri. Lundh departs from Bæskades on 6th September, his barometric measurements almost completed. The journey north from there went via Vina and Jøralholmen to Bossekop, which suggests that they may have taken a boat trip via Alta River.

A number of zenith measurements were recorded at 10 selected stations, of which Luvddiidčohkka was observed again the following year. The 10 points in 1846 were Tyven, Fuglenes, Håja, Ávjovári, Spielgavárri, Bealjášvárri, Ádjit, Čaravárri, Nuhpealas and Luvddiidčohkka. Kouman stayed behind at Luvddiidčohkka until 13th September, but the wind, fog and snow squalls forced him to terminate his work before he was finished so that he could reach the last steamship in Alta harbour.

1847

In 1847 Klouman journeyed north "alone," but the work could not have been carried out without one or more assistants, able seamen, carriage drivers and carriers. Their names are not recorded in the sources. What remained were five stations: Vertical angle measurements of Haldde, Gosviktind Jemmeluftoiavi, Vardefjellet Balkisoaivve, Kåven Kaaven and Seilandstuva Jedki. 

From the surface of the sea the mountains along the coast of West Finnmark can appear to be high, but in fact the highest of them are only a little over 1000 metres above sea level. They do not have the same jagged peaks as those that can be seen from Lyngen and northwards to Øksfjord. But that does not mean that the mountains from Hammerfest to Alta were easy to climb. Many routes up to the summits are littered with rock boulders or small stone screes of various types. Screes can present a challenge both on the way up and the way down if you're carrying a heavy load in wet weather, when the lichen on the stones gets treacherously slippery. In some places, such as Håja today, the rock boulders are overgrown with heather and moss, and a misstep here can mean trouble. Sea fog is another phenomenon which makes trekking difficult in the coast's mountain terrain. It can come down suddenly and cause people to lose their sense of direction. It seems that a year earlier Klouman had replaced his heavy universal instrument Reichenbach with a lighter Repsold theodolite, but it was still a heavy burden which had to be carried carefully up and down. Klouman had many arduous trips in 1847. We can only surmise that on a beautiful clear day when Klouman stood on the targeted mountain top, the view which met him must have been more fantastic than all of the man-made signal towers which had been built in the flatter tree-clad landscape below.

Klouman started at Haldde on 13th July and worked his way north towards Seilandstuva Jedki. The weather was not on his side "Every attempt at a reasonably accurate adjustment of the signals failed due to the dense air and strong winds. In the afternoon it started to rain."

Klouman noted that on 17th August at Station XV Jedki, the temperature was between 6.7 and 5.4 degrees, the air was misty; the day had started with sunshine, but later came the fog and the rain. The next day, the 28th, the temperature had fallen to between 3.8 and 3.2 degrees. The wind was SSW, the air was misty and diffused. "On The 30th of August, another failed attempt to climb the high Snowmountain."

On 2nd September he succeeded in getting to the summit, but the fog suddenly descended and the low temperature (0.8 degrees) forced him to abandon his work. What route had they chosen up to Seilandstuva? In 1845 barometer readings were taken from Skreifjorden but that area seems to have steep parts, whereas the climb up from Bårdfjordbotn or Jøfjorden has gentler slopes up to the top at 1079 metres above sea level. If "Ellida" was hired during that summer it is probable that they also chose a sheltered mooring place from the strong south-westerly winds.

Klouman climbed Seilandstuva five times that season before declaring that his work was done. He ended his diary in 1847 with these words: "Since the approach of winter was forewarned by the fallen snow which did not melt on Jedki, it was seen as more necessary to determine the previously unobserved angles on Lodizhjokki so that the results obtained might be deemed satisfactory." Still remaining that year was the work at Lodiken Luvddiidčohkka. The zenith measurements here were taken on 13th September. The temperature was between 3.4 and 3 degrees, and there was a light south-westerly breeze even though the air was misty and diffused.

A summer with a lot of wind, rain and fog was a trial for the surveyors' need for clear visibility and the instruments' need for a firm anchor to the ground. But despite the cold summers with fog, rain and wind, the team had produced the angles at the stations in the network's connection from Ádjit to Fuglenes.

1850

From the 1850 fieldwork season there is more information and a comprehensive report from Lindhagen, where he also includes a letter from Klouman. This report was published in Struve's publication: "Arc of the Meridian. Of 25° 20´, between The Danube and the Glacial Sea." In addition there is a diary containing angle measurements and a short report from Klouman. Can it be the difference in background and perspective which makes the researcher Lindhagen more generous in his descriptions than the army officers?

The goal of the season was to complete the zenith measurements and establish a basis in Alta as well as carrying out astronomic observations at the end-point. Since Klouman had no training in the method for establishing a basis, he spent some time in the company of Lindhagen in Poulkova, just south of St. Petersburg. Struve had been made director of the new central observatory at Poulkova in 1839.

During this period Klouman and Lindhagen practised the techniques of measuring a base by guidance of Struve. The instruments were also checked and adjusted by the observatory technician Mr. Brauer.

On 21st May Lindhagen and Klouman left Poulkova with the technician Lysander and a servant. They boarded the steamship "Neptune" in Kronstadt, a harbour town west of St. Petersburg, and sailed to Copenhagen. The voyage took 3.5 days. A Norwegian steamship "Nordcap" was ready to take them on to Norway.

They arrived in Kristiania on 28th May and stayed there for 13 days. Here all the instruments they had brought with them, as well as extra instruments supplied by Christiania Observatory, were inspected together with Ch. Hansteen.

Lindhagen wrote that despite family commitments Klouman had started off north earlier than the rest of the team via the land route to Trondheim. The others took the steamship "Prinds Carl" to Trondheim, and from there they went together on board the "Prinds Gustav" to Bossekop, where they arrived on 25th June.

The technician Lindhagen and a servant stayed behind in Bossekop with all the instruments, whilst Klouman and Lindhagen continued on to Hammerfest to build an observatory in Fuglenes. They reached an agreement with a local carpenter to carry out the work in three weeks according to their instructions. They stored their instruments with a tradesman in Fuglenes, probably a Mr. Robertsen, before returning to Bossekop.

Seventeen days at sea came to an end, and Lindhagen wrote that they couldn't quite agree on their impressions of the tour. He himself thought that the west coast of Norway which forms an archipelago was both unattractive and monotonous, whereas the interior of the country was beautiful and varied. He found the whole trip tiring, not helped by the weather which was wild and stormy.

Measuring of base in Alta

In Alta they considered the two alternatives for suitable terrain for the measurement of the base. They had to establish a baseline to obtain an accurate scale in the system for the chain of survey triangulation. A base is dependent on flat terrain. The distance between the end-points A and B of the basis is usually between 2 and 5 km. They agreed that the most cost effective alternative was the line from Elvebakken to Bukta. As they were staying 6 km away, they were forced to move closer to the baseline. They were provided with lodgings at Doctor Klingenberg's in Altagård. In addition to providing accommodation for Klouman, Lindhagen and Lysander, Doctor Klingenberg also assisted with the measuring work. The signal cairns were also made at Altagård. 

In order to measure a baseline there needed to be several people. Klingenberg's job was to see that the four men they had hired moved the rods and setting up the tripods.

Klouman's and Lindhagen's job was to clear the poles and read the graduations separately, and afterwards compare their results for each reading of a rod. Lysander's job was to stand beside the theodolite's telescope and adjust the placement of the poles - align the rods. The work went according to plan; all that disturbed them was the mosquitoes.

On 12th July there was only one decision remaining. Since the last side in the extended triangulation net had to coincide with one side A`B` in the chain of survey triangulation, they had to decide whether the base should be connected with the principal side Haldde-Nuhpealas or Balkisoivi-Luvddiidčohkka or Nuhpealas-Luvddiidčohkka. They agreed that weather conditions along the coast made the mountain tops more exposed to rain and poor visibility with a greater risk of the signals and the signal cairns being ruined. Therefore it was more practical to connect the baseline to the one principal side Nuhpealas-Luvddiidčohkka. The tasks and the responsibility were divided between Lindhagen and Klouman. Before they parted ways they had decided which stations next to the base a should be included in the expanded network and Klouman had to make a reconnaissance journey to find the other suitable stations and built signal cairns for these.

Klouman accompanied Lindhagen to Hammerfest to indicate where the stations near Fuglenes should be; Seilandstuva Jedki was particularly important for the angle measurements to Fuglenes. This had not been possible on their first journey to Hammerfest due to fog. They decided to take a small diversion and so continued on the ship to Nordkapp, where they had a wonderful break as tourists before the call of duty brought them back to work.

Extended triangulation net in Alta

Klouman returned to Alta and started a reconaissance journey. He took along with him enough manpower. Lindhagen related that "Klouman, as head of a caravan composed of 6 horses and as many guides, departs for the interior mountains on 27th July."

The extended triangulation net has eight stations, but there were only three of these that were seen as important. Klouman explained this in a report to Struve: "The signal on the triangulation point at Haldde had collapsed, and expediency called for using the triangle side Lodizhjoki – Nuppivarri with a choice of 8 intermediate points, namely: Rautassvarre, Vuovgolvarre, Peskavarre, Store Reipas, Skuådevarre, Lille Reipas, Kongshavnfjeld and Rafsholmen. Of these Peskavarre and Lille Reipas can only be regarded as support points to strengthen the triangle net. The triangles these points form are not good enough on their own, but as they are connected to each other, the length of every main side can be determined with several values."

Taking Klouman's own notes as a starting point, we can trace his probable route:

He recorded the readings at Vuossogalvari from 27th July to 29th July, at Nuhpealas 31st July, Luvddiidčohkka 6th August, Helletoppen Ravttasbeaski 9th August, Store Raipas 16th August and finally 26th August at Skoddavarre. The signals had to be rebuilt at several places, and signal cairns mounted. The only problems they had were that the horses ran off one day, and that mist, wind and rain made the measuring difficult.

Klouman sent a letter to Lindhagen on 18th August asking him to come to Alta to assist in the work on the first triangle, the one which formed one side of the basis. Lindhagen arrived at Bossekop on 26th August, while Lysander took care of the instruments and set up a chronometer in Hammerfest. Using the Poulkova universal instrument, Lindhagen measured the first triangle which is Peska, and the end-points of the basis line at Lille Raipas and Elvebakken. In addition it was important to confirm the sea-level at Bukta to achieve an equalling of the levels between Altafjord and Bottenviken. When this was completed, Lindhagen went back to Hammerfest and Klouman could go home.

Astronomic observations in Hammerfest

From the astronomical measurements at Fuglenes in Hammerfest there is a report by Lindhagen which describes the work in detail, but he has also taken the trouble to write down his impressions of the town.

Lindhagen and Lysander had been in Hammerfest for five weeks before Lindhagen went to assist Klouman. These five weeks had been somewhat problematic. Poor visibility and not a single whole day without clear weather were not conducive to good observations. He was to work out determinations of times and the zenith (vertical angle) and the determination of latitudes. For the latitude figures, Lindhagen had in advance found out which stars were to be observed, but he had to add two new stars because some were simply impossible to be seen.

He had lodgings in the town, probably at the hotel run by Mr. Rostad and had to walk 2 versters (2.1 km) to the observatory at Fuglenes. At the start he had planned to walk there as soon as the weather cleared, but often it clouded over before he got there. He decided to be as much as possible on-site at Fuglenes, "that isolated pile of rocks," to make as much use of the clear moments on-site as he could. He became increasingly desperate about the weather. For a whole month he had not seen a patch of blue sky. He wrote that for the local townspeople a good day meant partly clouded with occasional sunny periods.

Lindhagen did not have a positive impression of the west coast of Norway. He regarded Hammerfest as "the extreme north." His descriptions are rather like those of Arthur Campbell in his book "Reiser i Finnmark og opphold i Hammerfest 1820-1821." But the town had grown since those early days. Lindhagen estimated that the population of Hammerfest was about 700 on the south-westerly corner of the small inlet to the town, where 300 sailing ships entered the harbour every year. He wrote:

"One is tempting to believe that people here live close to destitution. That is certainly the case for the natives of the country the Lapps. With regard to the other inhabitants it is completely different. The merchants and their employees live an easy, if not to say, a luxurious life such as one rarely encounters in regions better favoured by nature. Certainly grapes do not grow here, but one finds the juice of grape, wine, in such abundance that one tend to believe it is a polar attraction of great intensity."

When Lindhagen returned from Alta to Hammerfest on 8th September there were just two steamship departures remaining before the town was isolated for the winter. Klouman was to leave at the end of September, and 13th October was Lindhagen's last chance. In the last weeks the weather improved; it was colder and clearer, giving him several good days for observations and getting results. He finished his work on 12th October.

The baseline station points A and B, the end points at Elvebakken and Bukta, and the triangulation point at Fuglenes were preserved for the winter storms. "When the brick pillar over the triangle point's metal bolt was removed, the one that had carried the weight of the universal instrument, the bolt, was exposed. The bolt was covered with a thick layer of tallow and then by a piece of wood. Which completely insulated it. Finally, a watertight stone wall was built around the triangle point." The observatory was to be preserved for as long as it could manage the climate, and the key was handed over to the burgomaster of the town of Hammerfest. The aim was that all these station points would be taken care of under "the supervision of the burgomaster, with instructions that minor repairs should be carried out when the wear and tear of time made it necessary."

The results of the project have been evaluated in later years. These show that uncertainty about the determination of the geodetic arc's total length is about 4 mm per km. For the Norwegian sector, the uncertainty is somewhat bigger, about 15 mm per km. There may be several reasons for this. Many of the measurements were carried out in strong winds. Instruments may have varied in quality, and different operational procedures may also have had an effect on the results. Nevertheless, the results are impressive when one takes into account the instruments and measuring methods that were available at the time.

Concluding remarks

This presentation is mainly based on logbooks, reports and correspondence. The topography of West Finnmark was decisive in the choice of which 15 geodetic stations were important for the chain of triangles. The same is the case with the base line and the extended triangulation net. The greatest challenge according to the sources was the climatic conditions, but one may assume that the relatively large and impassable areas have been a major challenge demanding thorough logistics. The sources are somewhat lacking inasmuch as they do not mention logistics, transport assistance, cairn building and organizing the surveying. Nor do they mention the culture and landscape in which they were operating. Perhaps Captain Th. Bang's records (1873) explain the phenomenon: "As soon as assistant no.1 notifies that the instrument is in place, the whole panorama is changed to a mathematical field of study where the prominent points alone stand out as top points in the chain of triangles."

Referances:

Bang. Th. (1873). «Landmålerliv i Finmarken». Kristiania.

Brooks de Capell Arthur: «Reiser i Finnmark og ophold på Hammerfest 1820-21"

dˈ Aunet Léonie. (1968) “En Pariserinnes reise gjennom Norge til Spitsbergen Anno 1838”. Oslo: H.Aschehoug &Co.

Harsson B. G. (2005). “Struves meridianbue inn på UNESCOs liste over verdensarven” Statens Kartverk.

Harsson B.G. (2007). «Om det grunnleggende for kartfremstilling om Struves meridianbue og jordens form» Statens Kartverk.

Lindhagen D.G. (1860). “The 1850 Expedition to Norwegian Finnmakenen” in «Arc of the Meridian. Of 25°20ˈ Between The Danube and the Glacial sea. Measured from 1816 to 1855. (F.G.W. Struve) Addition B.

Mkrtychan, Vladimir. (2013). The Struve Geodetic Arc: Pathway to Global Recognition.

Pettersen Bjørn Ragnvald, 2011, KART og Plan 1-2011.«En Repsold-teodolitt i den arktiske forlengelsen av Struves meridianbue»

Printz Axel. (1955) «Landmålerliv i midnattsol». Oslo: Gyldendal.

Smith, J.R. (2005). “The Struve Geodetic Arc.” International Institution for History of Surveying & Measurement.

Zorgdrager Nellejet (1997). «De rettferdiges strid. Samisk motstand mot norsk kolonialisme». Vett &Viten As.

ARCHIVE: Kartverkets rapporter 1840 til 1865. Barometermålinger 1845 af C. Lundh. Barometer Observasjoner under Gradmålingen i Finnmarken aar 1846 udført af C.A.B. Lundh. Klouman & Lundh 1846. Klouman 1847. Zenithdistanser vedkommende Gradmaalingen i Finnmarken 1846 og 1847 af F. Klouman. Vinkelmaalinger. Lindhagen 1850: Die Gradmessung in Norwegen. Klouman 1850: Vinkelmaalinger. Photo and illustrations is borrowed from Kartverket (the Mapping Authorities). The chain of survey triangulation and the extended triangulation net on the maps are made by Per Christian Bratheim. Kartverket.