Iso-Horila Hill aka Horilankero

The measurement point of the Horilankero is nowadays known as Iso-Horila or Horilanvaara. It is located about 20 kilometres northeast of the municipal centre of Ylitornio, on the western side of the village of Ratasvuoma.

The top of the hill is heavily wooded. At the top is a bolt drilled into the rock, which acts as a land survey anchor point and is surrounded by lush vegetation.

On the eastern side you can see the houses and fields of Ratasvuoma – otherwise the views from the top of the hill are dominated by forests.

Iso-Horila Hill is the central point in Maupertuis’ chain of survey triangulations – all triangles in the chain end up there, forming a heptagon around Iso-Horila.

The scientists used the heptagon to check their chain of triangles. The sum of the angles of a planar heptagon had to be 900 degrees. The sum of the angles of the heptagon on a curved surface such as the Earth had to be greater than 900 degrees. The angle measured by the expedition was 900° 1′ 37”.

The expedition left Iso-Horila on 18 August, after spending five days there. The next day they saw from Aavasaksa that the hill was on fire. A carelessly extinguished campfire had ignited a forest fire. Maupertuis sent 30 men to fight the fire. In addition to the forest, the fire destroyed a marker erected on the hill.

Pedre, the expedition’s French servant, knew the exact location of the marker, and with his help the marker was re-erected. A number of men were left on standby in case a fire broke out again.

The Iso-Horila forest fire also disrupted measurements at other points in the chain of triangles. For example, the southern point of the baseline in the village of Niemi (or Niemis) and Huitaperi Hill had difficulties due to thick smoke that reduced visibility.

Iso-Horila rises next to the open mire and field landscape as a high, forest-dominated hill. On its slopes are extensive rock outcrops and ancient shorelines dating back 10,000 years, but they are not visible in the surrounding landscape because of the forest cover of the lower slopes.

Like Aavasaksa Hill, Horilankero is a moraine-domed hill. After the last Ice Age, the peaks of the highest hills remained as islands. These hills are referred to as domed hills because the ancient waters did not wash away their moraine cover.

The domed crown of Iso-Horila is about 400 metres long and 200 metres wide. The top of the hill is covered by a primeval-like spruce forest, and the landscape is enclosed.

There is a small private nature reserve in the Iso-Horila rock area.

Sources:

Husa, Jukka ja Teeriaho, Jari. Luonnon- ja maisemansuojelun kannalta arvokkaat kallioalueet Lapissa. Suomen ympäristö 6/2015. Ympäristöministeriö, Suomen ympäristökeskus. Helsinki, 2015.

Maupertuis, Pierre Louis Moreau de. “Maan muoto”. Maan muoto ynnä muita kirjoituksia Lapista. Ed. Osmo Pekonen. Väyläkirjat, 2019 (orig. 1738).

Outhier, Réginald. Matka Pohjan perille. Maupertuis Foundation and Väyläkirjat, 2011 (orig. 1744).


A map

Guidelines for using the map
  • Red = Measurement point of the triangulation chain.
  • Green = Walking route.
  • Blue = Arrival from the main road (highway 21).
  • Markers: Tap or click to get more information about the destinations.
  • Zoom out: Shows the location in the triangulation chain.
  • Drop icon: Locates the user’s location on the map.
  • Measure tool: Measure distances between locations.

Open the map in a new browser window.


On the old map

Iso-Horila on the map drawn by Réginald Outhier (Carte du fleuve de Torneå, 1736).

Want a map for yourself? The map is currently sold as a poster (225 mm x 707 mm) in the shop of the Museum of Torne Valley (address Torikatu 4, Tornio).


Information

WGS84N 66°27’53.6″ E 24°00’15.3″
WGS84N 66.4649, E 24.0043
ETRS-TM35FINN 7374928, E 366555
UTM (WGS84)35WLP 66556.52 74929.993
(Estimated location of the measurement point.)

224 m

One way 2 km.

Iso-Horila Hill (aka Horilankero) is located 22 kilometres northeast of the municipal centre of Ylitornio. At Aavasaksa, turn east from Highway 21 onto the Raanujärventie road (road 930). Follow this road for about 18 kilometres, then turn north to the Ratasvuomantie road. After 6 kilometres, the road splits to left and turns into Ratasjoentie road. Iso-Horila is immediately on the left side of the road.

Iso-Horila can also be reached from the northwest. Turn east from Highway 21 at Ratasjoki. Drive on the Ratasjoentie road for approximately 10 kilometres. Iso-Horila remains on the right side of the road.

There is no marked trail or visible path to Iso-Horila.

A forest road starts from the Ratasjoentie road and ends about 800 metres further on in a small gravel extraction area. From there, you can continue trekking diagonally upwards.

The measurement point is at the highest point of the hill, in the covered crown area.

Kaakamavaara37 km
Huitaperi26 km
Aavasaksa14 km
Niemivaara14 km
Pullinki22 km
(Distance as the crow flies.)

The 10th of July 1736
From the 13th to 18th of August 1736

The 19th of August 1736. ”- – – On their return from church, it was said that the forest of Horrilakero was on fire; this turned out to be true: after dinner we saw from the top of Avasaxa the smoke of the fire; it even prevented our observing the angles of the extremities of the base, or seeing Horrilakero. We were obliged to send an express there to know if the signal was not dameged; as for the rest, the weather continued fine, and the nights rather cold.”

Réginald Outhier. Journal of a Voyage to the North (Journal d’un voyage au Nord), 1744.

The 10th of July 1736. “- – – we directed our Course upwards to a place the nearest we could find to a Mountain that seemed to suit our purpose. And from thence a March of three Hours over a Morass, brought us to the foot of Horrilakero. Though extremely fatigued, we got to the top of it, and passed the Night in cutting down the Wood that covered it.

Most part of this Mountain is a reddish Stone, interspersed with a fort of white Crystal, of an oblong Form, and laid parallel-wise. Here the Flies, more merciless than those of Niwa, were not to be driven off by Smoke. We were obliged, notwithstanding the excessive Heats, to wrap our Head in our Lappmudes, (a fort of Gown made of Rain-Deer Skins) and to cover us over with Branches of Firr, and even whole Trees; which rather stifled us, than defended us from these troublesome Animals.”

Pierre Louis Moreau de Maupertuis. The Figure of the Earth (La Figure de la Terre), 1738.

Pictures from Iso-Horila

The pictures open in large size in the gallery by clicking on the picture.


The expedition on the map

Réginald Outhier has written a detailed description of the expedition’s journey from Paris to Tornio and back. The journey took two months each way and was made by boat and wagon. On the way back, the expedition was in a shipwreck in the Bay of Bothnia.


Measurement points and other destinations