Historical aspects of the Welsh slate industry

D Dylan Pritchard MA FSS


With this article we conclude our survey of the expansionist period in the history of the slate industry. This period may be said broadly to have covered the first three‑quarters of the nineteenth century. The estimated output of British slate increased from 45,000 tons in 1793‑the peak year of the boom which immediately preceded the Napoleonic wars‑to some 504,000 tons in 1877, when the apex of the great building boom in the 'seventies was reached; in the intervening eighty‑four years the output had increased more than eleven‑fold. The rapidity of this growth will be appreciated when it is pointed out that it was almost equal to the rate of expansion in the coal industry during the same period.

Over most of the period 1793 to 1877 the industry displayed to a marked degree the spasmodic alternations of activity and stagnation which characterise all constructional industries, but it was seen that the trend in output was steeply upwards throughout the period. The underlying causes of this upward trend in slate production were examined in some detail. These factors fell into two main categories : firstly, those social factors arising from the progressive nature of our industrial economy and, secondly, those external and internal economies which were partly cause and partly effect of the expansion of the slate industry itself.

The basic factor was the phenomenal increase in population ‑ from less than nine millions in 1801 to nearly twenty-six millions in 1881 in England and Wales - and its movement from the agricultural to the industrial areas resulting in the development of new centres of economic life and and the unprecedented growth of many towns and cities. The number houses in England and Wales increased from 1,633,000 in 1801 to 5,218,000 in 1881. There was clearly a tremendous demand for roofing materials to roof all the new houses, factories, etc. which were built and there were certain factors which enabled the slate industry to capture a progressively increasing proportion of the market for roofing materials.

Prior to the Industrial Revolution the prohibitive cost of transporting bulky, heavy, and comparatively fragile commodity such as slate to distant markets had confined production within very narrow limits. Most of the quarries were situated on the slopes of inland mountains and the cost of bringing the slate to a convenient shipping place was prohibitive. We saw how the old pack‑horses and panniers gave way to carts and wagons as roads were built and these in turn were superseded by iron tramways. In 1801 the Penrhyn Quarries were linked with Port Penrhyn by a tramway; in 1824 a tramway was constructed from the Dinorwic Quarries to Portdinorwic four years later the Nantlle Quarries were linked with Caernarvon in the same way and in 1836 a tramway connected the Festiniog quarries with Portmadoc.

The dawning of the Industrial Age saw a revolution in transport facilities and not the least important of these was the widespread network of canals which were built. Canal transport was several times cheaper than land transport and the canal system enabled the industry to send its product to inland towns for the first time and this greatly extended the market for slate.

The inland waterways attained the zenith of their prosperity about 1830 when the opening of the Liverpool and Manchester Railway ushered in the "Early Railway Age." The mileage of British railways increased from 4,606 miles in 1848 to 14,874 miles in 1877. One by one the major slate ports had been linked up with the general railway system ‑ Port Penrhyn in 1848, Portdinorwic and Caernarvon in 1852, Portmadoc in 1867 – and the competition between the railways and coastal shipping brought freight rates down on land and water. This extensive and rapid development of railway communications brought slate within reach of those industrial and agricultural areas where canal transport was lacking and where slates had hitherto been virtually unobtainable on account of the cost of carriage.

Throughout the period under consideration slates were increasing in popularity and the determining factor was the comparative all‑in cost of roofing with slate and with competitive materials. From 1825 to 1880 it was much cheaper to roof with slates than with tiles in the London area; slating was cheaper than tiling by 80 per‑cent. in 1845, 55 per cent. in 1855, 45 per cent. in 1865 and 39 per cent. in 1880. In view of the very wide margin between comparative costs it is not difficult to account for the growth in the slate industry.

So long as the costs of inland carriage remained prohibitive for distances exceeding fifteen to twenty miles, the market for slate had been confined to the sparsely populated areas immediately adjacent to the producing areas, and to those coastal areas which could be reached by cheap water carriage; on the other hand it was possible to manufacture tiles in most of the regions where population was growing, so that tile manufacturers had long enjoyed a natural monopoly in catering for the expanding demand for roofing materials in the inland markets, but with the development of canal transport, and, later, of railway transport, the competition of the lighter, more durable, and cheaper roofing slate ousted the tile from many of the local markets which the latter had successfully monopolised for centuries. In inland towns slate superseded tiles, except for decorative architecture, and even in rural areas low‑pitched slate roofs replaced the more picturesque roofs of thatch or tiles.

Another important factor which contributed to the expansion of the industry was the unprecedented growth in the foreign market after 1867. Slate exports increased from 12,670 tons, valued at £56,681 in 1867, to 58,140 tons, valued at£311,932 in 1876 ‑ a level which has never been exceeded.

The fundamental factor underlying the remarkable progress of the industry up to 1876 was the expansion in the domestic and foreign market brought about by a revolution in transport and a tremendous growth in the volume of residential and industrial construction. The economic forces which enlarged the potential market for slate brought in their train certain important developments within the industry itself. The first three-quarters of the nineteenth century was a period of experimentation and innovation and there were revolutionary changes in methods of production and marketing.

During the eighteenth century the quarries were nothing more than shallow excavations and methods of production were primitive in the extreme but the expansionist period witnessed revolutionary developments in the science of quarrying. Man operated turntrees and horse whimsies were superseded by inclined planes, water‑balances, and, later, by steam motivated contrivances for lifting the slate blocks and rubble from the workings to the quarry bank. Primitive hand‑pumps were soon displaced by steam pumps. The wheelbarrow gave way to the horse‑drawn truck and, later, to the locomotive. Tools used by the rockmen in extracting slates from the rock‑face, by the miner in driving levels and sinking shafts, by the quarrymen in splitting blocks and trimming slates, were greatly improved. Cornish miners working in the Welsh copper mines initiated the quarryman into the mysteries of blasting rock with black powder. The safety fuse made the use of explosives safer; dynamite, nitro‑glycerine and other powerful explosives were introduced for the removal of waste rock. By the ‘seventies sawing machines had been introduced into the Merioneth slate mines and into a few of the major Caernarvonshire quarries, several types of machines for trimming slates were in use. Boring machines were used in a few quarries.

The mechanisation of the industry, as well as production on a large scale, brought with it great improvements in the lay‑out and construction of quarry buildings. More important, perhaps, was the general realisation that the opening and developments of quarries had to be done scientifically and that it had to be done with an eye to the future. Improvements in methods of production as between different concerns in the industry were very uneven but it was these improvements which made it physically possible for the industry to increase the volume of its output so rapidly, and helped to keep costs of production low so that slate could be marketed at a price substantially lower than, that of competitive materials.

There were many outstanding developments in the marketing of slate during the expansionist period - towards the standardisation, diversification, and classification of the product, and in the marketing agencies themselves - but it is important to remember that for the last fifty years of this period the demand for slate normally greatly exceeded the supply, so that little attention was paid to improving the marketing organisation of the industry and some of the developments that took place were to have a  detrimental effect upon the industry when the expansionist period was followed by a period of contraction and stagnation in the 'eighties. In the seventies the marketing organisation bore the hall‑mark of the rugged and extreme individualism which characterised the industry and whereas the organisation was adequate for the disposal of the product in a period of plenty, it clearly reflected a state affairs in which there had been little need to bother about perfecting it.

The expansion in slate production would have been impossible if new capital had not been attracted to the industry. The rapidly expanding domestic and foreign market, the progressive rise in slate prices, the absence of foreign competition and the negligible competition from other British slate producing areas, were all mutually determining factors which encouraged capitalists to invest in Welsh slate quarries. The apparently inexhaustible supply of excellent slate rock, the internal and external improvements in transport facilities, the technological improvements in methods of production, the absence of labour disputes (until the 'seventies), were other contributory factors which induced entrepreneurs to sink money in the trade. Another important factor was the handsome profits made by the owners of the Penrhyn and Dinorwic concerns and the shareholders of the Welsh Slate Company. Other concerns also made substantial profits, of course, but it was upon the extreme profitability of these three concerns together producing some 60 per cent. of the total output of Welsh slates that the full glare of publicity was turned in the technical and financial press.

It would be difficult to overestimate the importance of the Companies Act of 1862 in promoting slate quarry enterprise and the industry was particularly quick in adopting the limited liability company form of business organisation, especially in the slate mining districts of Merioneth where economic penetration by English capital had been carried further than in any other Welsh slate producing district. By 1882 we find that almost half the business units engaged in the North Wales slate industry were limited liability companies. It is interesting to note that in the four years 1863 to 1866 fifty‑eight new limited companies were registered to carry on slate quarrying in North Wales, and their total authorised capital amounted to the total of £2,877,500; it does not follow that anything like this amount of capital was actually invested by these companies in slate‑quarrying but it illustrates strikingly the eagerness of the British investor to sink vast amounts of capital in the industry. The investment boom during the 'fifties, 'sixties and 'seventies of the last century exceeded anything that has since been experienced in the industry. Slate quarrying attracted a great flow of capital throughout the first three-quarters of the nineteenth century and thus made possible the expansionist period in the history of the industry.


Aspects of the Slate Industry 21: The Expansionist Period 11

Quarry Managers' Journal February 1945