Heath and Reach is dotted with a number of sand pits or quarries, some in use, some disused. Many of these were created by two principal local firms, J.Arnold & Sons Limited and George Garside (Sand) Limited. A number of these pits were north-west of the angle formed by Shenley Hill Road and Mile Tree Road. One of these was Twenty One Acres Pit, owned and worked by Arnold's.
In 1896 an article in Gardening World said of Twenty One Acres pit: "Returning to Leighton Buzzard, we journeyed in a northerly direction, till we came to Mile Tree Road Sand Mine, Shenley Hill, covering an area of 14 acres. This pit or quarry is connected by means of a light railway with a "tip" or "shoot" by the side of the Mile Tree Road, thus affording a ready means of carting the sand to the railway station or elsewhere. Here may be seen heaps of sand of four or five different qualities. The first is white or silver sand of the best quality for horticultural purposes; also for filtration of water and sewage. Mr.Arnold supplies it to the East London, New River, and Grand Junction, and other water companies. Filtering and sewage sand, and that used for particular purposes, is screened and otherwise prepared. The second quality is semi-white. The third is grey sand used for mixing with cement, exceptional value for cement work of all descriptions being pure silicate perfectly free from saline or deleterious material found in other sands; it requires no washing or screening, being ready for immediate use; and the fourth is useful for brickwork in cement. Down in the bottom is a stratum of very fine argillaceous sand having a silky softness, and suitable for moulding purposes".
"This pit is the oldest, and we noted the spot where the existence of silver sand was first discovered. In its earlier days a Birmingham firm used the sand in the manufacture of glass. A considerable area of the ground here has been worked out, and the land is again under cultivation for farm crops".
"Following the line of rails we soon arrived at the present workings, of which we first give a superficial view as it appeared to us. The surface consists of arable land, in some places quite shallow. Beneath this comes a layer of blue clay of variable depth….the overhead line of rails, with iron trollies, is utilised for conveying the clay to that side of the pit which has been worked out. The rails are sloped so that the trollies run down with their own weight, and the clay is tipped into the played-out working. Immediately beneath the clay in some places comes a pan or layer of iron sandstone, that often requires blasting to break and dislodge it. This is of a dull, dark brown colour, and the grit is often as coarse as bird shot. Beneath this comes a loose material, of the nature of iron-oxide or ochre, and varying in colour from a bright orange to old gold or yellow. This peculiar sand is also well seen at places in the cutting through which the light railway runs. Beneath this comes silver or siliceous sand of the varying qualities above mentioned, but each in separate places, so that it is dug out and kept separate, but requires no other preparation or cleaning beyond screening. Here and there amongst the sand are thin layers or seams of very fine quartz pebbles, colourless, white, pink, amber, blue, and black all mixed together and very interesting. Veins, seams, or isolated patches of pale or deep yellow, reddish, or other coloured sands occur at various depths, and are generally horizontal, or dip at an angle as laid down by water in very ancient times. They serve to give a parti-coloured appearance to the sands where they occur, but may be altogether absent, leaving the sand either grey or pure white".
"Geologically this formation belongs to the Lower Greensand, a marine deposit overlying the Weald Clay. The two deposits constitute the Lower Cretaceous. The outcrop of this formation commences or terminates at Devizes (whichever way it may be looked at) and forms a narrow band running diagonally across England in a north-easterly direction, and uninterruptedly till it comes to Aylesbury. A little to the south of Leighton Buzzard it commences again and runs to Ely in Cambridgeshire. Commencing again at Fordham, in Norfolk, it continues to Hunstanton on the Wash".
"The Lower Greensand is fossiliferous and very interesting, both to the geologist and botanist. The top layer of clay…is Gault, and contains coprolites in greater or less quantity. Coprolites also occur below the sand, and at various depths in it. They consist of wood, mineralised with phosphate, more or less infiltrated with iron and silica; also of casts of mollusca or marine shells, bones, and other matter. Many things occur like fruits enclosed by a crust of iron, and others of these crusts enclose a quantity of loose sand. Bits of wood, often very much like pine in structure, occur at various depths in the loose sand, and we pocketed a fine piece in which the layers of wood were quite evident. Another piece of the trunk of a tree would have girthed 3 feet and was very heavy, owing to much iron in it. Iron-ore was formerly worked in the neighbourhood of Leighton Buzzard. An old-world Cycad was described in 1867, under the name of Cycadites Yatesii, by W.Carouthers, Esq., of the British Museum. Not far off Pinites have been found in the same geological formation. Some of the wood is soft and unctuous like bog peat, and stains the fingers black. How many thousands of years these old trees have been buried the geologist is unable to say".
"The ancient sea had worn away or denuded much of the Weald clay, and laid it down again in the Lower Greensand beds, so that the latter contain fossils that do not belong to them of right, but lived at an earlier period of the world's history. These fossils were, until recently, worked for manure, but here they are simply turned into the bottom to be buried with the clay on the top. The nodules in the base of the Gault or blue clay are also phosphatic. The Gault has here been washed away to a thin layer 1 feet to 6 feet deep, or thereby. Judging from the quantity of fossil wood, there must have been land at no great distance off. With regard to the sand itself there is a fine mass of it yet in a solid, that is, undisturbed condition".
The Rating and Valuation Act 1925 ordered that every piece of land and building in the country be assessed to determine the rates to be paid upon it. The valuer visiting Twenty One Acres Pit [DV1/C254/97-99] noted that with the neighbouring Nine Acres pit the total area worked was 23.450 acres.
Buildings comprised: a weather boarded and corrugated iron motor shed and a weather boarded and corrugated iron mess room. The valuer commented: "?15 men working. Been working about 3 years on northern part of pit. Get out 100-120 tons a day but depends on weather. Steam navvy working in north-west corner on untopping. He further noted: "These two pits "Nine Acres" and "Twenty-One Acres" adjoin but are worked separately. Nine Acres is old and apparently more expensive to work. Twenty One Acres is very good. One gang working on untopping another on getting out sand. Trucks pulled out of pit by motor and horses. Separate rails for untopping. On light railway.
In part of the pit was Sandpit Cottage [DV1/C254/96], occupied by the foreman, T.Webb. The cottage stood in a third of an acre and was built of brick, sandstone (no doubt found in the pit) and tile. The building comprised a kitchen, scullery, two reception rooms, three bedrooms and a cellar with a brick and tile barn and earth closet and weather boarded and felt store shed outside. Not surprisingly the valuer noted: "Miles from anywhere".
The May 1934 edition of the enchantingly named Cement, Lime & Gravel magazine had a feature on J.Arnold & Sons and said this of Twenty One Acre pit: "Twenty One Acre Quarry presents a contrast to the foregoing Quarry [Chance's Pit]. White, red and orange sands and dark red ironstone immediately meet the eye. The overburden consists of 20 to 30 feet of stiff Gault clay, the Gault being the bed between the Lower and Upper Greensands, the latter member of the Cretaceous System being entirely absent from the neighbourhood".
"A 1 yard Ruston-Bucyrus Steam Shovel, mounted on road wheels, deals with the overburden and the tough ironstone is catered for by a portable Broome & Wade compressor, running a rock drill and concrete breaker. the sand itself is worked in the usual bench method for selection and there is some selection here".