Distance: c.1150m. Direction: WNW
Bridleway No. 2 and Footpath No. 2 starts opposite a terrace of four red-bricked cottages at the south end of Everton. They were constructed in 1915 for employees of the Pym estate (TL 198508). Local gossip says that they were provided for returning soldiers from the First World War, provided they helped in the construction. Most conscripts would have been estate labourers so learning some construction skills would have been thought useful. A Greensand Ridge signpost and a carved tree stump marks the route. The bridleway follows another ancient trackway, between Sandfield Close and Brookland Close. It is known today as ‘Warden Gap,’ along which farmers took their cattle to and from grazing on the fields on and below the ridge.
Once you go through the kissing gate (TL 197509) it becomes Footpath No. 2. You can get some stunning views along the Greensand Ridge. These are quite exceptional for Bedfordshire, especially when there is a storm approaching on the prevailing south-westerly winds or when the sun is setting on a fine evening. There are plans to erect a greensand monolith by the spring once you pass through the gate and place a seat where you can enjoy the view. Similar monoliths can be found at other points along the Greensand Ridge Walk. Until 1975 there used to be a line of several hundred-year-old elm trees that followed the ridge top. The Dutch elm beetle affected about 80% of the country’s elms and the remedy was wholesale felling. Rotten tree boles up to three metres across can be found in some places along the ridge top.
This gently sloping field, known as Long Hill with a gradient of 1:10, is the main sledging run in the village. Many of the local youngsters, and the more active adults, get out their sledges, toboggans and snowboards after only a few centimetres of snow.
Once you start to descend the hill you are going back millions of years in geological time. The top of the hill at 66 metres is the remains of a much higher ridge that was heavily eroded during recent ice ages. How many metres of sand the advances and retreats of the ice sheets scraped off is unknown. It is very likely that much of the softer Upper Greensand was washed away when the last ice sheet melted between 13,000 and 9,000 years ago. It is the Lower Cambridge Greensand that makes up Bedfordshire’s Greensand Ridge. It started to be deposited about 94.5 million years ago on top of impermeable Oxford Clay. This deep bed of clay started to be laid down in shallow seas about 500 million years ago, when this part of NW Europe was much further south, about 28o S. of the Equator. Now its surface is the heavy soil that clings to your boots or wellies in wet weather. When you’re scraping it off just remember it’s really ancient, many millions of years old!
There is a theory that asteroid activity about 94.5 million years ago caused a mass extinction, burning up the oxygen, causing fiercely hot winds and a several hundred metre high tidal wave that flooded the coastal areas. The impact would broken through the few kilometre thick Earth’s crust, caused extensive earthquake and volcanic activity, and released vast quantities of poisonous Carbon Dioxide and Sulphur Dioxide into the atmosphere. It is claimed to have wiped out about 70% of all life. The section of the Earth’s plate upon which this part of Northwest Europe lies, would have been shifted into the desert latitudes from which the Greensand originated.
The reason for it being called greensand is that it contains minerals of glauconite, blue-green crystals with a complicated chemical formula (K0.08 R1.33 R0.67 [Al0.13 S3.87 O10] OH2) that turn green when they are first exposed to the oxygen in the air. However, after a while they change to the dark brown colour that you will notice further south on exposures in the Sand Hills above Sandy.
Interestingly, there is a bed of coprolites, described by some as a giant graveyard, at the junction of the Greensand and the Oxford Clay. These are phosphatised remains of Jurassic land and marine organisms mixed with some similar remains from Jurassic times. Locals thought they were fossilised dinosaur droppings but, whilst some flat-bottomed lumps certainly resemble sun-dried turds, the deposit included the teeth, bones and claws of such dinosaurs as dakosaurus, dinotosaurus, craterosaurus, megalosaurus, scelidosaurus and iguanodon. There were also remains of marine reptiles like ichthyosaurus, pliosaurus and plesiosaurus as well as the bird pterodactyl. There were fossils of shark, whale, crocodile, turtle and a host of marine organisms. The most common was ammonite - a member of the squid family that feasted on the decaying remains. Land animals including elephant, hippopotamus, bear, horse, tapir, armadillo, hyena and ox were also found in the bed as well as unrecognisable lumps of inorganic phosphate. The Cretaceous fossils were probably washed out of their sediments by floodwaters and redeposited amongst their Jurassic relatives.
Their bones, teeth, claws, shells and fossilised stomach, intestinal content and droppings were in great demand during the second half of the 19th century. It was their high phosphate content the 19th century entrepreneurs were after. They were dug out from below the overburden, in pits down to over 8 metres in places, washed, sorted and transported to the nearest canal, river wharf or railway station, (in this case Sandy or Potton) and shipped to manure manufactories in London, Ipswich and Wolverhampton but also to local ones at Cambridge, Ashwell and Royston. Here they were ground to a powder, dissolved in sulphuric acid and converted into superphosphate — the world’s first artificial chemical manure.
It was a lucrative business. Arthur Peel, MP, who lived at that time in the Swiss Cottage on his Sandy Warren estate, possibly used the thousands of pounds royalties he got from allowing the coprolites on Sandy Heath to be worked to fund the construction of Sandy Lodge. The lowest tender was £6,695. The present day landowners are the Royal Society for the Protection of Birds (RSPB) who use it as their headquarters and education block. There were some workings in Everton where explosives were needed to blow up iron pan that overlay the fossil deposit. An account of the diggings, ‘The Dinosaurs on Sandy Heath’, can be found in the local libraries. If you want to see the deposit in situ, pass through the kissing gates and follow the overgrown and often muddy streambed to the south. About halfway down the path that runs down alongside it beneath the trees and hawthorn bushes there is a mound of them embedded in the clay (TL 197509). More details about the industry can be found in the account of Bridleway 29.
This field used to be used for grazing donkeys and Shetland ponies, which explain the heavily chewed tree trunks, lower branches, fences and gates. This explains the aluminium angle iron across the bars of the field gates. However, in Spring and Summer one can often meet cattle. Their grazing habits unfortunately do not include thistle. The donkeys are sometimes kept in the field to the north above the new path. The bare patches in the grass are their toilets. Donkeys tend to urinate in the same spot and their urine is so acidic that it burns the grass. The kissing gate for the new path can be seen in the northern corner of the field (TL 196510).
At the bottom of the hill to the west you need to continue through the kissing gates into the next field. This is pasture for cattle and a close examination of the heavy clay soil reveals how cracked it often is, even in wet weather. This has been caused by the gradual lowering of the water table, particularly since 1941 when this low-lying area was drained in preparation for Tempsford Airfield. A barn in the southwest corner of this pasture field was one of a number of farm building dismantled at the beginning of World War Two in a deliberate attempt to make this area look deserted.
This was Jasper Maskelyne’s work. He was an illusionist famous for his magic shows in London before the war. Surprisingly, these skills were in great demand during wartime. He was made a major and his ‘gang’ adapted his conjuring and illusionist expertise to the battlefield on a large scale. His magic was put into practice here. The construction of the site involved the knocking down Village Farm, several agricultural labourers’ cottages at the bottom of Victoria Hill, an old keeper’s cottage near the entrance to the base and several other farm buildings. All the hangars and domestic buildings were camouflaged to blend in with the surrounding farmland and it is said that they were all thatched – to give the impression that they were farm buildings. Genuine tractors were left but moved occasionally in the fields and yards. Cattle were deliberately grazed on some of the fields when the runways were not in use to make the pilots of any German ‘planes that managed to fly over think it was used for agricultural purposes. It succeeded. It is said that the aerial photographs taken by German pilots who flew over were interpreted as a disused airfield.
The planes only used the airfield on a few days each month — the nights of the full moon. They took off with no lights. They flew with no lights and landed with none. They did not want the enemy to notice them on their secret missions. 138 Squadron took responsibility for parachuting supplies to the numerous resistance groups in occupied Europe as well as dropping secret agents. 161 Squadron were involved in landing agents in isolated fields, picking them up along with vital information and VIPs who needed lifting out.
The path now follows one of the drainage ditches cut by huge excavating equipment into the clay soil when the airfield site was being developed. Most of these drainage ditches are heavily overgrown. The reason why is eutrophication. Some of you may recall studying it in your Science or Biology lessons. The farmers’ increased use of artificial chemical fertilisers since the 1840s, particularly superphosphate and nitrates, has improved yields but increased the phosphate content of the groundwater. As a result it stimulated plant growth in ditches, streams and rivers, so much so that they can get completely overgrown. You can see how this ditch has become dominated by horsetail, supposedly the oldest plant on earth. Make sure you or any children do not pick any and take it home. Once it starts growing it is impossible to get rid of. Breaking it off by the roots only doubles its growth as little nodules occur every few centimetres along its root system. It will spread like wildfire in any soil. However, it is claimed that it is possible to extract gold from its ash after burning its roots.
About 500 metres further on the path passes alongside a hawthorn coppice to the north before meeting the concrete track of the Roman Road (TL 189514). Bridleway 3 continues to the north and bridleway 27 to the south.