This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol5", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
(Contributed by Walter Hooker)
Those varieties found in the first-named formation are more used in positions where strength and toughness are required, as in engine beds, foundations, etc. Their toughness makes them difficult to work, and they are therefore not in favour where much cutting and ornamentation are required.
The sandstones of the Devonian formation - in Scotland better known perhaps as the "Old Red Sandstone" - form a numerous class, and are to be found very generally distributed in parts of the Grampians, near Dundee, Edinburgh, Cromarty, and in Dumfriesshire. In England the countries of Hereford, Gloucester, Monmouth, and Devon form the localities mostly productive of this class of stone.
Although called the old " Red " sandstone, stones of this formation are not invariably of this colour, being at times found of a greyish or yellow colour, or of varying shades up to red.
Some of the best known quarries are the following :-
Craigleith, near Edinburgh (now almost worked out, and to a great extent replaced by Hailes stone, of similar character), a greyish sandstone exceedingly durable and of fine weathering properties, mainly composed of fine particles of quartz and mica, cemented by a siliceous material, can be got of any convenient size up to blocks 10 or 12 feet long. Its composition is about 97 per cent of silica, 1 1/2 per cent of carbonate of lime, and a trace of iron. Its cohesive power is about 7800 lbs. per square inch. Specific gravity, 2.3.
Corsehill, and the neighbouring Closeburn, near Annan in Dumfriesshire, is a fine red sandstone, very workable, of even grain and of good weathering qualities. Composition, about 96 per cent silica, a small percentage of carbonate of lime, and a little iron. Its specific gravity is 2.26. Cohesion, about 7000 lbs. per square inch. To be had in fairly large blocks.
In Devonshire good sandstones are found in Newnham and Hangman Hill, but they are not much known outside these districts.
There are also quarries of good and useful stone in Hereford, Gloucester, and Monmouthshire. The quarry at Wilderness (Forest of Dean) produces a fine hard stone of exceeding strength and resistance to crushing. Large blocks are to be procured.
Carboniferous Sandstones are mostly, as their name implies, obtained from the coal measures of both England and Scotland. The coarser stones of this class are used for heavy work, engine beds, bridges, etc. The finer varieties are more laminated, and are suitable for pavings, landings, steps, and copings. They are almost all durable, hard, and of great resistance to crushing, having admirable weathering properties, especially as regards resisting the action of wet and atmosphere in large towns.
Of the ' grit' or coarse stones of this class the most important quarries are as follows :-
A fine even-grained grit of a drab colour, a very good weathering stone, to be had in large blocks and long lengths. Composition, 96 per cent of silica, a trace of carbonate of lime, and about 1.5 per cent of iron and alumina. Specific gravity, 2.6; cohesion, 7000 lbs. per square inch; crushing strain, 670 tons per square foot; weight per cubic foot, 162 lbs.
A fairly good weathering stone of even texture. Colour, light brown. To be procured in fairly large blocks.
An exceedingly strong and hard stone, colour red (sometimes brown or grey), suitable for situations where heavy strains are likely to be met with. To be had in large blocks.
Brownish grey colour, very durable, extensively used for general building purposes where superimposed weight is to be encountered.
A sound hard stone of good weathering quality, of close even texture. Colour, a fine light brown.
An exceedingly reliable and durable stone, of an even blue or grey colour, suitable for all ordinary building purposes, but hard to work. Large blocks are obtainable. Weight, about 150 lbs. per cubic foot. Contains about 96 per cent of silica and a small proportion of carbonate of lime and alumina.
A tough durable stone, hard to work, of a slaty colour. Suitable for kerbs, steps, and landings, and all positions where a good wearing surface is required. Weight, about 162 lbs. per cubic foot.
Great resistance to crushing. Contains about 97 per cent. of silica.
A good useful stone of a blue colour and fair weathering quality. To be obtained in good sized blocks.
A durable stone of good weathering quality. Colour, light brown. Weight, about 130 lbs. per cubic foot. Composition - silica, 95 per cent.; carbonate of lime, 1 per cent.; iron and alumina, 2.3 per cent. Cohesion, 4000 lbs.
Somewhat similar to the above-mentioned stone. It stains on being much exposed to the weather owing to the amount of iron in its composition. Weight, 150 lbs. per cubic foot. Composed of silica, 93 per cent.; carbonate of lime, 2 per cent.; iron and alumina, 4.5 per cent.
A fine even-grained and strong stone, much used for docks, bridges, quays, and pavings. Can be had up to the largest sizes. Weight per cubic foot, 160 lbs.
A close-grained stone, nearly white. Is useful for all ordinary building purposes, and takes a good arris.
A good average stone of a light brownish colour. To be had in good sized blocks. Is heavy and weathers well.
A stone of average quality of a rather coarse grain. A light brown in colour. To be had in large blocks. Suitable for heavy work. Weight, about 140 lbs. per cubic foot.
A good even-grained stone of a light brown colour. In much request in the district for all building work. Is very suitable also for steps, thresholds, landings, copings, etc. Good weathering qualities. Weight, about 150 lbs. per cubic foot.
Scotgate Ash. (near Pateley Bridge). - There are several varieties of this stone, contingent on the position of the various beds in the quarries. The texture is fine grained and very even and compact. It stands very heavy pressures. In colour it is of a light brown. Suitable for steps, landings, copings, etc. Weight, 160 lbs. per cubic foot. Resistance to crushing, 740 tons per square foot.
The only sandstones of any known value in this formation are found at Newbiggen in Cumberland, and one or two other quarries in the valley of the Eden. The stone is a rich deep brownish red, of good even consistency, and free working. It is of good average weathering quality, if care be taken to set it on its natural bed. Weight about 140 lbs. per cubic foot.
This formation is mostly found, insomuch as it affects the question of building stones, along the western counties of England and the Welsh borders. The Keupar division usually provides the best and most durable qualities. It is, as a rule, easily worked, being of a uniform texture and of even grain, but is often not a very good weathering stone.
A very even-grained stone of good weathering properties. In colours, bluish grey and nearly white. Can be had in good sized blocks. Useful for all ordinary building work. Weight, about 140 lbs. per cubic foot.
A fine-grained, easily worked stone. Colour, yellowish white (also red). Weight, about 142 lbs. per cubic foot.
A fine stone of even grain and sound weathering quality. Very much used locally. Of a good red colour. Yields good large blocks. Weight, about 138 lbs. per cubic foot.
A good reliable stone, sound and durable, to be had in blocks up to 5 tons. Colour, nearly white (there is also a red variety). Weight, 133 lbs. per cubic foot.
A good serviceable building stone of a light grey colour. Is to be had in convenient blocks for general purposes. Weight, 125 lbs. per cubic foot.
A very durable, compact, and sound building stone, easily worked and suitable for all ordinary building work. Weight, 135 lbs. per cubic foot.
There are very few known quarries of this formation, the principal being near the vicinity of Whitby, the general characteristics of the stones of this formation being strength and toughness, and also of capability for fine work. Stones that have been exposed for many centuries to the ravages of weather and time have shown little or no marks of exposure beyond the growth of lichens on their faces, the tool marks of the mason remaining as clear at the present day as when they were first fixed in situ. Other stone, however, has given evidence of great decay in the course of time. It would be feasible, therefore, to premise that great care should be exercised in choosing the beds of the quarries for the stone required, and also as to the setting of the stones on their proper quarry beds. It has to be remembered that with certain stones it does not always follow that the plane of cleavage is the original bed. Undue pressure caused by upheavals or other convulsions of the underlying rocks sometimes create a plane of cleavage varying in angle with the natural bed of the stone, in accordance with the direction of the force exerted in the superincumbent mass. A much more sure guide to the true bedding than the natural cleavage is to be found in the way in which embedded fossils or shells lie in the stone. If it contains any of these at all they will always be found lying flat on the bedding.
The above remarks may be considered as applying generally not only to sandstones but to other sedimentary rocks.
This is a good weathering stone of a uniform nearly white colour. It is especially suitable for piers, sea walls, and other positions where durability and strength are required. It is also capable of fine work, for mouldings and ornamentation.
It can be procured in good large blocks. Weight, 150 lbs. per cubic foot.
This is a good general building stone, but rather hard to work, and more suitable for foundations and understructures. In colour it is a light brown. Weight, 128 lbs. per cubic foot.