De Volharding is a smock mill

Smock mill

The smock mill is a type of windmill that consists of a sloping, horizontally weatherboarded tower, usually with six or eight sides. It is topped with a roof or cap that rotates to bring the sails into the wind...

 in Jislum

Jislum

Jislum is a small village in Ferwerderadiel in the province Friesland of the Netherlands and has around 50 citizens . There is a restored windmill in the village, De Volharding....

, Friesland

Friesland

Friesland is a province in the north of the Netherlands and part of the ancient region of Frisia.Until the end of 1996, the province bore Friesland as its official name. In 1997 this Dutch name lost its official status to the Frisian Fryslân...

, Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 which was built in 1872. The mill has been restored to working order and designated as being held in reserve in times of emergency. It is listed as a Rijksmonument

Rijksmonument

A rijksmonument is a National Heritage Site of the Netherlands, listed by the agency Rijksdienst voor het Cultureel Erfgoed acting for the Dutch Ministry of Education, Culture and Science.-History and criteria:...

, number 15632.

History

De Volharding was built in 1872. It drained the Ald Piip Polder

Polder

A polder is a low-lying tract of land enclosed by embankments known as dikes, that forms an artificial hydrological entity, meaning it has no connection with outside water other than through manually-operated devices...

, which has an area of 50 hectares (123.6 acre). The mill can pump water into the polder as well as draining water from the polder. The mill worked until 1955, after which it became derelict. On 28 December 1972, it was bought by Stichting De Fryske Mole (Frisian Mills Society). The mill was restored by millwright

Millwright

A millwright is a craftsman or tradesman engaged with the construction and maintenance of machinery.Early millwrights were specialist carpenters who erected machines used in agriculture, food processing and processing lumber and paper...

 Tacoma of Stiens

Stiens

Stiens is the largest town within the municipality of Leeuwarderadeel, with a population of about 7,800. The town hall of the municipality is located in Stiens....

 in 1973. A further restoration was undertaken in 1994. In 2000, a new Archimedes screw was fitted by millwright H Kloosterman. In 2006, the mill was officially designated by Wetterskap Fryslân as being held in reserve for use in times of emergency.

Description

De Volharding is what the Dutch describe as an grondzeiler. It is a two storey smock mill on a low brick base. There is no stage, the sails reaching almost to the ground. The mill is winded by tailpole and winch. The smock and cap arecovered in vertical boards. The sails are Common sails. They have a span of 9.2 metre. The sails are carried on a wooden windshaft. The windshaft also carries the brake wheel which has 32 cogs. This drives the wallower (17 cogs) at the top of the upright shaft. At the bottom of the upright shaft, the crown wheel, which has 28 cogs drives a gearwheel with 25 cogs on the axle of the Archimedes screw. The axle of the Archimedes screw is 240 millimetre diameter. The screw is 710 millimetre diameter and 3.45 metre long. It is inclined at 19°. Each revolution of the screw lifts 900 litres (198 imp gal) of water.