Practical Chemistry

Aside

Following on from our last blog post about lime mortars and traditional buildings – there are a series of upcoming workshops over the next few months on using hot mixed and other traditional lime mortars, aimed at practitioners in the north of England.

Further information – lime-mortar-workshops-january-to-march-2017

The Chemistry of Buildings

Building Conservation Team

The Building Conservation team at the National Park have a vested interest in keeping the area’s traditional buildings in good repair so as to maintain and secure this particular element of the North York Moors’ special qualities. We have a new Advice Note on using lime mortars, the rudiments of which are explained below.

Most buildings in the North York Moors were traditionally constructed using stone and lime mortars (to bind the stonework together), often with earth and rubble filled cores. Lime was used for bedding and pointing the stonework and for rendering. Rendering with mortar was used to cover poorer-quality masonry underneath or to make a building more weather proof, for example on the coast. Most historic buildings were constructed from materials found locally and this contributes to what is distinctive about the ‘local vernacular’.

When it comes to repairing a surviving traditional building it is important to understand how they work. These buildings are usually of simple construction and built using breathable materials. Bricks and stone are bonded with flexible and permeable mortars made of lime and sand which allow the building to ‘breathe’. When it rains moisture is absorbed into the external surface but is then able to evaporate through the more porous pointing or render. Using a lime based mortar or render for repairs nowadays means that this process can continue.

In contrast modern cement mortars and renders along with plastic paints, waterproof sealants and damp-proof courses all act as barriers to a traditional wall’s natural ability to breathe. The trapping of moisture within permeable materials like stone can exacerbate the very problems these products are trying to resolve. The use of cement-based mortars can have a significant negative visual (photo below left) and physical impact on traditional historic buildings. The photo below (right) shows the extent of stone decay caused by the use of a cement mortar. Because the cement is much harder than the stone, moisture cannot evaporate through the joints and instead evaporates through the stone causing it to ‘weather away’ through premature erosion.

You can usually tell what type of mortar has been used most recently; cement based mortars tend to be dark grey and hard in appearance and texture whereas lime based mortars are generally lighter and softer in appearance and texture. Because they allow the surrounding masonry to dry out the colour of the stone will also lighten.

There are a number of different types of lime mortars/renders. Replacing like for like is important.

Non-hydraulic lime is the raw material produced when limestone (calcium carbonate) is fired, often called ‘quicklime’ (calcium oxide). It is sold in a slaked form (with water) as lime putty which is then mixed with an aggregate (e.g. sand) to produce mortars and plasters. These putty limes possess good breathability and flexibility and are ideal for use with soft porous materials allowing the maximum permeability.

Hydraulic lime comes in powdered form and will start to set as soon as it comes into contact with water. It is ideal for use in wet or very exposed situations or where there is a need for a higher compressive strength or a quick set. Hydraulic limes come in a variety of strengths e.g. NHL2, NHL3.5 and NHL5 – the higher the number the less flexibility and breathability the mortar will have.

Hydrated or bagged lime is a form of non-hydraulic lime which is sold as a powder. It is sold by builders’ merchants as an additive for cement mixes in order to give modern cement mixes more plasticity and workability. It is generally considered to be inferior to lime putty, not least because an unknown proportion will have reacted with carbon dioxide and set by the time it reaches the site.

Hot-mixed lime is made when quicklime is mixed with water and aggregate simultaneously. The vast majority of historic lime mortars were probably hot-mixed. There are several benefits of using a hot-lime mortar: it can produce cleaner work as there is less leaching, it has a easily-workable elasticity which produces solid and full joints, it appears to be more breathable and therefore more compatible with stonework, and it has potential for use in colder weather notwithstanding the requirement for protection from freezing during the curing (setting) process.

A standard pointing mix consists of a lime mortar mix of 1:2½ lime:sand (sand mix of 50% sharp sand and 50% builders sand) for a slightly recessed bagged finish. However there may be times when a bespoke mix is required such as when different colour sand is needed to match existing historic mortar.

Repointing is only needed where mortar has become loose, decayed or eroded to an extent that water has started to penetrate the joints. If the mortar is firm or so hard that it needs to be chiselled out then it is best to leave it in place as removal could damage the masonry. The repointing of delicate ashlar joints (made out of worked stone) is not generally advisable as the joints are so fine that getting old pointing out can lead to irreversible damage of the masonry.

If repointing is necessary joints should be carefully raked out manually or by non-electric tools (no angle grinders) to a depth equal to one and half times the width of the joint and never less than 35 mm. Great care must be taken to keep the edges of the stone intact and joints should never be widened. Work should not be carried out when there is a danger of frost or heavy rain (this is less important when using a hot lime mix). Mortar must be protected from drying out too quickly from wind, rain and frost by protecting the area. Rain must never be allowed to strike the mortar and stonework until the setting process is complete.

The mortar should be stippled as the initial set takes place, with a stiff bristle brush, to produce a textured appearance capable of shedding water and slightly set back from the stone outer surface to ensure the full arris (edge) of each stone shows clearly in relief.

The photo below (left) illustrates a good lime mortar mix and pointing method. The aggregate used in the mix has been exposed by brushing back the pointing to a recessed finish which allows the stone to be the dominant feature. The other photo below (right) shows historic pointing on an old outbuilding where roof tiles were used to fill in larger gaps between the stones, adding to its particular character and appearance.

If you need further information, or advice on sources of materials, or any clarification regarding the need for listed building consent or planning permission before re-pointing or rendering a traditional building, get in touch with our Building Conservation Team.

This Exploited Land – a poetic mix of Victorian beauty and brass

Tom Mutton – TEL Programme Manager

When businessmen visited the Beck Hole Ironworks in 1860 their report in the Whitby Gazette gave a beautifully poetic account of this new enterprise. Despite the author’s lyrical writing style the article also illustrates a perceived total domination over the natural world that was the foundation of the industrial revolution.

This is partly what This Exploited Land is all about. Although in modern times we may miss the elegant language of the Victorian era, many of us have a very different view of the natural world and the potentially devastating effects of humanity’s exploitation of the planet. The way that nature has reclaimed the mines of the Esk Valley and Rosedale is humbling to see and shows us that we are surrounded by a beautiful and fascinating world that we should use our intellect to care for rather than abuse. To do this best we need to remember and learn from the past, being inspired by the monumental relics in the landscape and the stories from our ancestors who lived very different lives in the North York Moors we now enjoy.

Transcribed from Whitby Gazette 16 June 1860:

“…It is our pleasing duty to report the successful operation of the Whitby Iron Company’s (Limited) Works, at Goathland, which we noticed in our last impression as having been blown in on 7th inst.

A few of our principal townsmen spent Monday evening at those Works, and were delighted with the various departments. The magnificent engine which supplies the blast for smelting the iron from the ore moves round like a thing of life, and at once the ever-lasting hills of the valley resound with the voice as of a tide bursting upon our shores.

We heartily wish the Company success, as the pioneers in a pursuit which is destined to revolutionise the habits and maxims of the valley of the Esk, and with the facility of the rails and our own good port, we venture, the day is not distant when capital and enterprise will demand that the whole of the district become one grand scene of industry, and that, from one end of the valley to the other, Old King Coal, supported by the genius of man, will assert his power in developing those vast storehouses of wealth which, during the last few years, have attracted the attention of strangers to those exhaustless beds of minerals which nature has provided and stored up in this locality, for the use of man in the arts of civilised life. And Whitby will one day have to rejoice in the fact, that she is one of the principal ports in the kingdom for the export of iron to the commercial ports of the world.

Beckhole, the little village at the head of the valley where these works are situate, has now a strange sight to look out upon morning and evening, which are ushered in with a torrent of molten iron and a flood of lava gushing forth from the bowels of the company’s furnace. The sweet songsters of the woods and glens are now giving up their claim to the morning’s dawn and evening calm. The _________ voices of the sons of toil mingling with the music of the compressed air of the blast engine, wait for the dawn of the East, whilst the perpetual columns of vapour, smoke, and flame, tell of the presence of man, successfully reducing to practice the maxim of the company’s tablet, viz “Tis the prerogative of man to command, develope, and appropriate to his service the elements with which God has surrounded him.” The tablet at the foot of which the above inscription is fixed commemorates the incorporation of the Company, the date at which the first Iron was made upon the Works, and the names of the Directors; and was cast from the Iron first run from the furnace.

In this noble course of action the W.I.C.L., have led the way. We heartily wish them god speed, and doubt not the success which awaits their spirited enterprise; and hail with joy the event as a blessing to the surrounding neighbourhood, and the watchword to the progressive establishment if similar works, whose effect will be to convert this district into one of the most thriving seats of the iron trade of this country, creating labour for man and beast, and scattering in its train the blessings of trade hitherto unknown in the locality.”

WICL commemorative tablet - thanks to the Whitby Museum.

This tablet, referred to in the article and cast from the first Esk Valley iron, can be seen today in Whitby Museum.

It’s worth noting that Whitby Iron Company Limited was short lived – it was wound up in 1862.

Can you help?
There are two words in the article that are obscured by a tear in the paper from which it was transcribed – can you suggest what the missing words before ‘voices of the sons of toil…’ might be? please let us know.

Extract from the Whitby Gazette 16 June 1860 - thanks to Tammy Naylor.

This Exploited Land: the trailblazing story of ironstone and railways in the
North York Moors

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Fantastical fungi

Roy McGhie – Conservation Project Assistant

Fungi is found on every environment on the planet and plays a vital part in many ecosystems. They don’t actually belong to either the plant or animal kingdoms, they have their own. Fungi are key decomposers and so are crucial in terms of nutrient cycling. Because fungi don’t photosynthesise like plants (they don’t contain any chlorophyll) they instead rely on absorbing food from their environment to survive. This is why you will often see fungi growing on or around other plant material, living or dead. By decomposing organic plant material, particularly lignin and cellulose that make up the bodies of plants, the locked up carbon, nitrogen and minerals are released and used again by other plants and organisms.

Fungi often form important symbiotic relationships with other organisms. These can be antagonistic (injurious to the host), mutualistic (mutually beneficial) or commensal (apparently neither injurious nor beneficial). One of the most well-known mutualistic relationships is that with mycorrhizal fungi. It is estimated that over 90% of all plant species are part of a mycorrhizal relationship and are dependent on it to thrive. Mycorrhizae are found between plant roots and the soil, and help other plants collect moisture and nutrients (such as nitrate and phosphate). In return the mycorrhizae are able to use the carbohydrates and sugars that the plants produce. It has been suggested that a single oak tree can have up to 19km of associated mycelium – these are the thread-like hyphae (filaments) that extend outwards from the mycorrhizal fungi.

For most fungi these hyphae are their main part. Even when these hyphae tangle together and are visible to the human eye we often don’t see them because they’re underground or within their food source e.g. a tree. Some fungi however produce fruiting bodies in order to release spores – these are the mushroom parts which appear when it’s warm and damp. The mushroom parts are short lived and die back within a season but fungi can live for years and years.

The North York Moors hosts a great variety of fungi types and their mushrooms, from waxcaps, inkcaps and milkcaps to chanterelles, boletes and russulas. Because of the amount of plant material available woodlands, particularly ancient woodlands, are an excellent place to see mushrooms in the late summer/autumn and some varieties in the spring. To encourage fungi on your own land leave deadwood where it is (either standing or on the ground) instead of clearing it away. Managed grasslands are also a good habitat to find mushrooms. Waxcaps in particular can be found on grassland around historic houses and churchyards, and also on grazed pastures. The best grassland fungi sites typically have a short turf, plenty of moss, are well drained, poor in nutrients and usually unfertilised. Many waxcaps form mutualistic relationships with mosses, so to encourage fungi in your own garden don’t remove the moss.

Over the centuries the hundreds of types of fungi in England have been given graphic common names like ‘Ashen Knight’, ‘Bitter Poisonpie’, ‘Dead Man’s Fingers’, ‘Dryad’s Saddle’, ‘Flaming Scalycap’, ‘Humpback Brittlegill’, ‘King Alfred’s Cakes’, ‘Mealy Bigfoot Webcap’, ‘Old Man of the Woods’, ‘Papillate Pinkgill’, ‘Plums and Custard’, ‘Powdercap Strangler’, ‘Scurfy Deceiver’, ‘Slippery Jack’, ‘Sordid Blewit’, ‘Witches Butter’ … I’ll stop there.

Fungi are an often underrated element of biodiversity; working away, mostly out of site, maintaining healthy ecosystems that are so important to the natural environment..

A few types of wild (uncultivated) mushrooms are edible, many taste of nothing, and others are toxic and quite often deadly. You always need to be absolutely sure which is which if you’re intending to eat one. Foraging in England and Wales is not illegal as long as what is collected is not intended for commercial use. However please remember that most of the North York Moors is privately owned and you’d need permission from the landowner to range over private land.

Picking mushrooms won’t necessarily damage the fungi but the more that are picked the less chance the fungi has of reproducing.

Fungi in and around the North York Moors - mixture of fungi possibly including Candlesnuff - copyright Tom Stephenson, NYMNPA.

For more on fascinating fungi – have a look at The British Mycological Society and the Fungus Conservation Trust websites. Local Naturalist Societies are often great sources of local knowledge.

A to Z: a lump of Ls

L

LAMINARIA

Laminaria is a genus of 31 species of brown algae commonly called Kelp. Some species are also referred to as Tangle. They are characterized by long, leathery laminae (leaf blades) and their relatively large size. There are two common Laminaria that grow along the North York Moors coast.

Laminaria digitata or Oarweed is commonly found along the local coastline and grows in the transition zone between the open sea and the deeper part of the rocky shore. The plant can grow up to three and a half metres long.  The fronds of the plant are hand shaped with fingers hence its species name digitata. They are sometimes (but not always) found still attached to the stipe or stem secured by a ‘holdfast’ at the bottom of the stem to a rock or ledge. After heavy storms this Laminaria can often also be found washed up on beaches after being ripped up by the strong waves and currents.

Laminaria digitata - image from The Seaweed Site: information on marine algae http://www.seaweed.ie/descriptions/laminaria_digitata.php

Laminaria saccharina or Sugar Kelp is another common kelp from the same transitional zone on the foreshore. This single stemmed seaweed can grow up to four metres long. It has a long leathery blade – unbranched and without a midrib – about 15 centimetres wide. The blade is flat but wrinkly and with wavy margins. It is also known as Poor man’s weather glass as it was used to forecast the weather: if it dries up the weather will be fine; if it swells up and becomes damp, rain is on its way.

Laminaria saccharina also known as Saccharina latissima - image from The Seaweed Site: information on marine algae http://www.seaweed.ie/descriptions/saccharina_latissima.php

Laminaria is an economically important genus. In the 18th century seaweeds were burnt to extract potash (potassium) for use in the glass industry to make the glass stronger, and in the 19th century iodine was extracted for medical usage e.g. as a disinfectant. Seaweeds have long been used as an organic fertiliser and spread on the land, because of the minerals they contain. Seaweed is also now used for the extraction of alginic acid used in medicine; in the manufacture of toothpastes and cosmetics; and in the food industry for binding, thickening and moulding. Please not that like most plants, seaweeds can also have detrimental (poisonous) effects.

LASERS at LASTINGHAM

Lastingham Abbey was originally founded in the mid-7th century AD by St Cedd of Lindisfarne as a Christian monastery. St Bede described the site as ‘among some High and remote hills, which seemed more suitable for the dens of robbers and haunts of wild beasts than for human habitation’. For whatever reason (Vikings have been suggested) it subsequently fell into eventual ruin. Monks from Whitby then re-established a new monastic foundation in 1087 but again it was abandoned as the monks moved on, with the work left unfinished.

St Mary's Church, Lastingham - copyright NYMNPA.

What is left on the site is St Mary’s Church, now the parish church of Lastingham. The building is mainly early Norman but with Victorian transverse arches and a vaulted roof added in 1879. The subterranean crypt beneath the church building – is particularly atmospheric. The dating of the crypt (e.g. whether it dates back to an original Anglo-Saxon building) and the usages of the crypt (e.g. whether St Cedd was reinterred there, making it a shrine) have long been debated.

Archaeological debates rely on evidence and data collection. In 2008 ‘early’ laser scanning of the crypt was undertaken by the University of Siena and the Landscape Research Centre. It was one of the coldest, dampest days imaginable on the Moors – so much so that the survey team (and the kit) needed to ‘defrost’ in the warmth of the nearby Blacksmith’s Arms pub afterwards. A short film clip – here – shows the scanning being carried out – it is clear that the technology has moved on a lot since. Back in 2008 the juxtaposition of the modern and ancient seems to add to the sense of eeriness.

LAURENCE STERNE
“I take a simple view of life. It is keep your eyes open and get on with it”

Laurence Sterne was born in Ireland in 1713. He came to the village of Coxwold on the south west corner of the North York Moors to be the Anglican Rector in 1760. He had previously attempted to supplement his clerical income with farming for a while but then tried his hand at writing instead, publishing a number of sermons and a critical pamphlet which was promptly banned. His first and most successful novel was ‘The Life and Opinions of Tristram Shandy, Gentleman’. He had written the first two volumes as family members died around him and his family life collapsed. Fortunately on publication in 1759 which Sterne paid for himself, ‘Tristram Shandy’ was an immediate success.

‘Tristram Shandy’ leaves out the strictures of ordinary linear plotting, and has no great conclusion or moral – instead “it is written in a bye corner of the kingdom, and in a retired thatched house, where I live in a constant endeavour to fence against the infirmities of ill health, and other evils of life, by mirth; being firmly persuaded that every time a man smiles, – but much more so, when he laughs, it adds something to this Fragment of Life” (Sterne’s dedication of Tristram Shandy to the Right Honourable Mr Pitt).

Sterne took very well to being a celebrated author both in London and the Continent. At the same time his fame meant that in 1760 he was appointed to a good living at Coxwold for the rest of his life with the security that entailed, and he could leave most of his clerical duties to his Curates. He published nine volumes in all of ‘Tristram Shandy’, the last in 1767, as well as ‘A Sentimental Journey through France and Italy’ (a spin off). Laurence Sterne died in London in 1768. Keeping with the tragicomedy of his life and work Sterne was initially buried in London – he may then have been dug up by Resurrectionists before being partly? reburied – but a skull and femur presumed to belong to Sterne were later removed and interred in the Church at Coxwold, whether he liked it or not.

Portrait of Laurence Sterne by Joshua Reynolds, 1760. Being painted by Joshua Reynolds is confirmation that Sterne was definitely a celebrity of his age. Laurence Sterne Trust.

Along with the Rectorage at Coxwold came Shandy Hall. This is the house where Sterne lived and wrote, in between sojourns in London, France and Italy. It is now the home of the Laurence Sterne Trust and is open to the public during the summer.

LAWTON REPORT

Professor Sir John Lawton chaired a panel considering “Do England’s wildlife sites comprise a coherent and resilient ecological network? If not, what needs to be done?” The panel’s report – Making Space for Nature: a review of England’s wildlife sites and ecological networks – was published in 2010.

One of the starting points was that in many cases habitats for wildlife were usually small and fragmented, missing the coherent and resilient ecological habitat connections across the landscape that would enable wildlife to spread and to move in reaction to change.

The report set out three objectives:
“1. To restore species and habitats appropriate to England’s physical and geographical context to levels that are sustainable in a changing climate, and enhanced in comparison with those in 2000.
2. To restore and secure the long-term sustainability of the ecological and physical processes that underpin the way ecosystems work, thereby enhancing the capacity of our natural environment to provide ecosystem services such as clean water, climate regulation and crop pollination, as well as providing habitats for wildlife.
3. To provide accessible natural environments rich in wildlife for people to enjoy and experience.”

The answer proposed by the report were that “To make space for nature we need more, bigger, better and joined up sites to create a sustainable, resilient and more effective ecological network for England…we need to do more to: 
i) Improve the quality of current sites by better habitat management.
ii) Increase the size of current wildlife sites.
iii) Enhance connections between, or join up, sites, either through physical corridors, or through ‘stepping stones’.
iv) Create new sites.
v) Reduce the pressures on wildlife by improving the wider environment, including through buffering wildlife sites.”

Figure 5 Enhancing ecological networks from 'Making space for nature' Report 2010

For the necessary management, restoration and creation of wildlife habitats the report suggested a number of approaches – including using levels of legal protection and designation, making the most of publically owned land, paying for ecosystem services and biodiversity offsetting, providing incentives through agri-environment schemes and the tax system.

The report offered a landscape vision of nature alongside people and it presented the encouraging idea that we can do things to make the situation better. It spelled out the interconnected benefits from, and the values of, the natural environment to wildlife and to people, including the possibilities of deriving multiple benefits from land-use so that everyone gains.

“It is a long-term vision, out to 2050, and defines a direction of travel, not an end-point. This vision will only be realised if, within the overall aims, we work at local scales, in partnership with local people, local authorities, the voluntary sector, farmers, other land-managers, statutory agencies, and other stakeholders. Private landowners, land managers and farmers have a crucial role to play in delivering a more coherent and resilient wildlife network.”

The Lawton Report was well received on publication. Many environmental organisations have set out their responses to the report since and are working in line with the principles set out within it. The North York Moors National Park Authority put the principles at the heart of our Management Plan in 2012 – our current habitat connectivity initiative is aimed at achieving long term effective wildlife connections along a number of strategic corridors.

LYKE WAKE WALK

The Lyke Wake Walk is a forty mile moorland crossing over the top of the North York Moors from Osmotherley on the western edge to Ravenscar on the coast in the east. The
idea came from a local man called Bill Cowley who issued an open challenge in The Dalesman in August 1955 to cross the moors on foot from west to east within 24 hours, and its continued as a standing challenge ever since. Everyone who completes the Walk within the 24 hours is entitled to become a member of the New Lyke Wake Club. Lately the Club has been working with National Park Authority Volunteers to ensure the classic route for the Walk remains accessible and erosion problems are tackled.

A ‘Lyke’ is a corpse, and a ‘Wake’ is the watch over a corpse before burial, so the Lyke Wake Walk should therefore be an historic route for carrying the local dead to their final resting place. Except that it actually isn’t. Instead it’s an evocative name given to a recent concept to bring people together to take up a challenge and to champion the North York Moors.

Previously on the North York Moors A to Z … A, B, C, D, E, F, G, H, I, J, K

This Exploited Land – hitting the ground running

Tom Mutton – TEL Programme Manager

This Exploited Land (TEL), our HLF Landscape Partnership Scheme, is now building up steam with projects starting on the ground and the recruitment of new project staff underway. As well as myself we’ve got Elspeth Ingleby as our Natural Heritage Officer and Thelma Wingfield as our Administrative Assistant. The remaining two TEL vacancies for a Cultural Heritage Officer and a Volunteer Coordinator are expected to be filled by January. Special thanks to Louise Cooke for building and nurturing the Scheme to where it is today. We hope Louise will continue to be involved with TEL and will see all the project ideas become a reality over the next five years.

One of the first projects underway is the repair of the landslip at the East Kilns in Rosedale. The landslip is on the line of the old Rosedale Railway and is a popular route round the top end of the dale. The remedial engineering works will maintain safe access along the path, enable vital practical access to the two sets of kilns which will be subject to major consolidation during 2017/18, and help conserve into the future the distinctive landscape feature of the railway embankment as it carves its way along the hillside.

Rosedale East landslip - before start of works. Copyright NYMNPA.

The works to stabilise the embankment and rebuild the path involve digging away all the loose material down to firm foundations and constructing four tiers of stone-filled gabion baskets topped with a new stone path. The front of the baskets that will be visible after the works have been faced with soil filled bags containing a specially selected moorland grass seed mix. Despite the cool autumn weather this seed is already germinating.

The works are due to be completed and the path reopened by mid-November.

During the works archaeologists have been keeping a watching brief to help identify and understand the construction of the railway. A couple of original sleepers were salvaged, one with the track shoe still in place. The profile of how the track was built up using waste from the calcining kilns (red/brown) and cinders from engines (black) can be clearly seen in the photograph below taken during the excavation.

Rosedale landslip repairs autumn 2016 - section through the railway track bed showing original materials used. Copyright NYMNPA.

Rosedale landslip repairs autumn 2016 - original sleepers from railway track. Copyright NYMNPA.

Regular monitoring of the landslip by local residents reported on the Rosedale Abbey Blog had showed the slip getting progressively worse so time was of the essence for these repairs at the beginning of TEL. Now the same residents have been reporting on the works underway and will continue to monitor the site as it recovers.

To sign up for the mailing list for This Exploited Land and find out more about our exciting Landscape Partnership Scheme – see here.

This Exploited Land: the trailblazing story of ironstone and railways in the
North York Moors

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A ‘Gothic’ icon

Ravens (Corvus corax) are a relatively common bird in some places. In the British Isles they currently breed mainly in the west and north. But they have been moving eastwards.

Single Ravens are now and again seen over the North York Moors. Excitingly, this summer saw the first breeding Ravens in the North York Moors for a long while, at least 50 years. Three chicks fledged.

Adult Raven near Ravenscar - copyright Graham Oliver, BTO.

The nest was near Ravenscar on the coast. Ravenscar and other places in the North York Moors such as Raven Hill, Raven Heath, Ravensthorpe, Raven Stones, Ravens Gill and Ravensgill Beck, usually share some kind of nearby cliff edge habitat (coastal or inland) where Ravens like to nest. The occurrence of these place names indicate that Ravens were more usual in the North York Moors in the past, so the fact that they have bred again in the North York Moors suggests a return and a boost to the natural heritage of the area.

These places were named so because of the presence of Ravens; Ravens have always been culturally significant. It’s not hard to see why. Their size, colour and sound is striking, but it is also their perceived cleverness, their carrion eating habits and their interaction with human society which gives them a special place in cultural history. Ravens have been loaded with superstitions and connotations. Wariness of the apparent watching and knowing nature of the bird causes unease. They are associated with premonitions of doom; seeing or hearing a Raven has been taken as a sign of imminent death. These dark associations continue, at least in part, today.

Raven - the Watcher by JestePhotography. http://jestephotography.deviantart.com/art/Raven-The-Watcher-532656250.

So in celebration of this age old cultural fear and to mark Halloween, here is an example of a local Raven tale. The lesson is – never look a Raven in the eye.

Some time ago a man was walking home over the moors.

It was already dusk but he didn’t mind because he didn’t have much further to go and he had made money that day.

He knew the way because he had walked it many times before. He counted the scarce land marks as he went till he knew there were only three more boundary stones to pass before the moors would give way to a gentler landscape and then it was only a few miles to his home.

As the gloom drew in he saw the first of the three boundary stones just ahead of him. A Raven was sitting on top of the stone. As the man went passed the bird didn’t fly away, instead it looked at him, cocked its head and called out in the silence

“Craaw craaw”
“Corpse corpse”

The man turned his head. The Raven still looked at him.

“Craaw craaw”

The man hurried on. He was starting to feel tired but he could see the glow of the lights of his village in the distance just over the horizon of the darkening moors. He thought about the warmth of his fire and the taste of his dinner.

It was getting colder and the greyness around him was turning to black. There were no stars in the sky, and he couldn’t see the moon. There were odd shapes on the moors, in the gloom – ancient silent burial mounds and twisted bitter rowan trees.

Just in front he saw the outline of the second boundary stone. There was a Raven sitting on top. The man didn’t look at it – he walked straight on, looking ahead. The Raven looked at him though.

“Craaw craaw”
“Corpse corpse”
“Corpse corpse”

The man pulled his coat around him. He didn’t know why he was mishearing the bird call. He tried to hum a tune, but he couldn’t think of one.

For a moment he thought about heading off the track to avoid the last boundary stone but he knew he couldn’t because then he would be lost. He thought about the people he’d heard of that had been lost on the moors and who had never got home.

He kept walking. He felt the damp blackness pressing about him. He couldn’t see the last boundary stone. He thought he should have seen it by now. The glow on the horizon didn’t seem any closer, in fact it looked to be receding as if it were being out blotted out by the dark.

He stumbled and nearly fell. There was the last boundary stone and there was a Raven.

“Corpse corpse”
“Corpse corpse”
“Corpse corpse”

The man stopped and looked at the Raven. The Raven looked back at him, eye to eye.

The man became aware of the dead around him and knew in fact he must be dead too. He could go on walking but would never get home. So instead he sat down next to the last boundary stone and waited.

The darkness gathered in.

free-clipart-lines-and-bars-mhmbqx-clipart-2

Ravens make a lot of different noises (listen here) – and can even learn to mimic words.

For a Halloween Raven-themed treat – both ominous and ghastly – try here.

Fostering hedgerow trees

John Beech – Land Management Adviser

Mature trees within a hedgerow network are an important feature in the countryside. This is where land managers across generations have allowed single hedgerow plants to grow to their potential, alongside hedgerow plants that are coppiced, laid, and managed to create a boundary. Hedgerow trees have no particular value in terms of land management, but have huge value for wildlife and for the landscape.

Re-laying a hedge - copyright NYMNPA.

Traditionally Elm, Ash and Oak trees were the dominant hedgerow tree species reaching heights of up to and over 30 metres tall, towering above the hedgerow corridors. Saplings that are allowed to grow higher than the surrounding hedge do not need to compete for light and therefore grow and spread their canopy high and wide up into the air. This provides a wonderful habitat kingdom for many species of wildlife, free from the clutch of ground based predators. Such trees act as key wildlife ‘stepping stones’ between woodland habitats and across a mixed landscape.

Large hedgerow tree near Low Askew - copyright NYMNPA.

The intensification of agriculture in the latter half of the 20th century including increasing field sizes resulted in the loss of thousands of miles of hedgerows along with their hedgerow trees. The outbreak of Dutch elm disease from the late 1960s onwards removed some 20 million elms from our countryside, mostly from hedgerows. It is therefore quite rare now to find a mature Elm tree within a hedgerow. Similarly Ash trees are now threatened by Chalara dieback.

In 1998 there were an estimated 1.8 million hedgerow trees in Britain (CPRE survey). Many of our over mature hedgerow trees today are beginning to die and slowly retrench. There is an adage that an Oak tree takes over 200 years to grow and then 200 years to die.

Planting hedgerow gaps between old hedgerow trees - copyright NYMNPA.

To check the loss of hedgerow trees we need to be planting new ones to replace the ones that are dying back. The 1998 survey revealed that only 1% of hedgerow trees were in the youngest age class (1-4 years old). Without successional planning there is a danger that these key features will be lost for good from the landscape and the disconnection between farmed land and semi natural woodland will become more marked than ever. It takes a leap of imagination but by planting now land managers will be leaving their mark on the landscape for their children.

Trees take time to grow. Native wildlife species use hedgerow trees but birds, bats and butterflies in particular favour mature hedgerow trees.

Hedgerow trees in the landscape - copyright NYMNPA.Tawny Owls take advantage of mature trees both as nesting sites and day roosts usually hiding close up against trunk. From a tree perch owls can see the movement of their potential prey on the ground below them. Bullfinches clamber amongst the branches searching for seeds, buds and insects. Treecreepers and Nuthatches use their Hedgerow trees in the landscape - copyright NYMNPA.acrobatic skills to forage for insects, nuts and berries and Woodpeckers drill away into the deadwood high in the canopy to make a home and feast on any tiny invertebrates in the wood. Butterflies such as Hairstreaks forage for honeydew from aphids and lay their eggs high up in the Oaks and Elms. Rich lichen communities also grow on the branches of old hedgerow trees.

In some of the older trees, holes and crevices provide ideal habitats for a variety of bat species. Around three quarters of British bat species are known to roost in trees. Bats use different parts of the tree for different reasons, depending on the time of year and temperature. In the summer bats use the higher canopy sites to have their young in warmer temperatures. In winter, they move deeper and lower into the tree to hibernate. Trees such as Oak, Beech and Ash are particularly suitable for bats, but any hedgerow tree has potential for a bat roost – especially if it has cavities in the trunk or branches, woodpecker holes, loose bark, cracks, splits and thick ivy. In Britain, all bat species and their roosts are legally protected by law.

Single hedgerow tree alongside an arable field - potential 'stepping stone' - copyright NYMNPA.

We’re working on enhancing wildlife corridors and connections through our habitat connectivity initiative, and as part of this we’re actively encouraging the planting of hedgerow trees where appropriate. With the loss of Elm and the threat to Ash, Oak is now the main species being planted in the North York Moors to become the hedgerow trees of the future. With good care and maintenance the trees should grow into vigorous specimens.

Mature hedgerow trees as a feature in the landscape - copyright John Beech, NYMNPA.

To foster hedgerow trees:

  • Select suitable saplings from within an existing hedgerow and add a tree tag to the top of it. This shows/reminds the person who cuts the hedge to leave this strong sapling to grow into a mature tree.
  • Alternatively, plant a hedgerow tree adjacent to an existing hedge to add variety and height. This has the added advantage of widening the hedgerow and enables useful wildlife buffer strips to develop along the hedge bottom. If there is an existing gap within a hedgerow that is wide enough to accommodate a hedgerow tree then plant a new tree there.
  • Try to avoid uniform planting and instead plant the new trees at irregular intervals along the hedge line. Planting two or three together may also be suitable for instance if a site is next to a field corner.
  • Plant trees with local provenance that will be used to the local conditions and be more likely to flourish.
  • It is best practice to add a tree guard or tube attached to a stake to protect a tree in its early years from stock, rabbits or deer. A mulch mat around the base of the tree helps to keep the weeds down. This will give the tree every chance to grow strong and straight.

Practical help and advice can be provided by the National Park Authority. Contact us.

Historical curios and curious patterns

Beth Davies – Building Conservation Officer

We visit a huge number of sites throughout the North York Moors during the course of our work and occasionally we’re lucky enough to come across something on the more unusual side.

Like this stone noticed on a farm in Danby – we think it was used as an egg cooler.

Egg cooler? carved stone on farm in Danby - copyright NYMNPA.

This stone (below) is in a field in Glaisdale and the owner advised me it was an apple press. There certainly appears to be a drain on the near side which would suggest it was used to collect some form of liquid.

Apple press? Glaisdale - copyright NYMNPA.It’s noticeable that the cross shape is very similar to those found on ‘witches posts’ in vernacular long houses, especially those in recusant Catholic outposts like Glaisdale. Did the cross have a purely functional purpose in getting the juice to run out in channels? … did it help protect the juice from evil misdoings by witches? … did the cross shape signify covert faithfulness to the old religion after the Reformation?

'Witch post' - Ryedale Folk Museum, Hutton le Hole. From Hidden Teesside http://www.hidden-teesside.co.uk/2014/08/06/witch-post-hutton-le-hole/

This (above) is a picture of a ‘witch post’ trans-located along with the rest of Stang End Cottage from Danby to the Ryedale Folk Museum in Hutton le Hole. The post is supporting the bressumar beam above and there is the heck (draught proof screen) behind. It’s called a ‘witch post’ because of the pattern carved at the top which is thought to be there to protect the house and the hearth. Similar carved posts in houses seem to be a particular feature of the North York Moors, but it’s not clear when they were first associated with witches.

The North York Moors contains a number of ‘cup and ring’ stones (see below). These are usually in-situ rocks which have been engraved in prehistoric times with patterns – the ‘cup’ markings are concave shapes and the ‘ring’ markings are concentric circles. These types of engraving are found in a number of places in Europe and beyond and it is this similarity of the ‘cup and ring’ patterns in different places that makes them particularly significant. There are various explanations of how and why involving semiotics, cryptography and mythology, as well as archaeology.

Cup and Ring stone near Roxby - more cup than ring - copyright NYMNPA.

Cup and Ring Stone near Fylingdales - copyright Blaise Vyner.

Cup and Ring Stone near Goathland - copyright NYMNPA.People like to leave their mark. Below is an example of 19th century rock art (graffiti) at an ironstone industrial railway site in the North York Moors – it shows a man in a top hat, and a bird. I don’t suppose there is any meaning behind it other than someone passing the time and representing what they were seeing around them.

Carved picture stone - copyright NYMNPA.

We’re always keen to hear about odd cultural remnants in the North York Moors and different interpretations of their functions. Please let us know if you can help.

Large engraved stone within drystone wall - copyright Roy McGhie, NYMNPA.