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  • Writer's picturePaul Whittle


On 14th June 1736 the Reverent William Gostling of Canterbury recorded “…I have got a piece of a huge bone (I suppose from an elephant’s thigh bone) petrified, which the dredgers of copperas stones fishes out of the sea”

In “The Harwich Story”, Len Weaver describes the “new and profitable” Roman cement industry which grew up in Harwich after 1812. Roman cement was patented in 1796 by the Reverend James Parker of Northfleet, Kent. Parker discovered the method after throwing a rock he found on the Isle of Sheppey beach into a fire, and hence it was sometimes called ‘Parker’s cement’. Most descriptively, Parker himself called it Aquatic cement’. It was a very rapidly setting ‘hydraulic’ cements and therefore most suitable for wet work including under-water work, sealing leaks in pipes and damp proofing Regency houses in London. The copperas stone was broken up, burned in kilns, ground into a powder and packed in 4cwt casks for shipment to all parts of the UK and northern Europe.

For more than 50 years after Parker patented his cement between 400 and 500 men were employed in the Harwich trade alone supplying about two million bushels (70,000 m3) annually.

It may not be generally known that copperas exposed to the weather is soon reduced to powder and that it can, with great advantage, be applied to improve the growth of vegetables. An experiment also showed that a slight sprinkling produced a crop of grass twice as heavy as that grown on land which had not been so treated. Confusingly, it is also reportedly a good weed killer.

Similar products to Roman cement including ‘Medina’ Cement and ‘Sheppy’ Cement were produced from septaria (clay-rich limestone) of the Solent and Harwich.

In 1826 the Topographical Dictionary of England recorded in its entry for Harwich “....About one hundred small vessels and boats are employed in or near the harbour in dredging for stone for making cement. The manufacture of copperas from stones, which are found in abundance on the shore, was carried on here in the seventeenth century, about which time an attempt was made to obtain potash from various seaweeds but it was soon abandoned….”

By 1835 there were five cement factories in Harwich with ‘some five hundred men employed in dredging the stone and manufacturing the cement’. The removal of ‘several hundred thousand tons’ of stone from Beacon Cliff caused changes in the set and strength of tides which threatened to silt up to the mouth of Harwich Harbour and in 1845 removal of stone was immediately stopped by The Commission on Harbours of Refuge. The consequence of this was to see a marked increase in dredging until, by 1850, up to 400 smacks from Kent ports, each with a crew of three or four, were dredging stone from the West Rocks off Walton with some off Brightlingsea and off Hythe.

In her “The History of Harwich Harbour”, B. Carlyon Hughes reproduces the report of Captain Washington of HMS Shearwater dated 19th January 1843 to the Harwich Harbour Conservancy Board following his survey of the harbour. His report includes the figure of “upwards of a million tons” of cement stone having been removed from the area since the traffic in cement stone started. He also gives an indication as to the depth the cement stone dredgers could reach when he writes “….the actual channels should be dredged so as to command a depth of 15 feet at low water, or at 27 feet at high-water springs; this would be attended by little expense, as the(stone) dredgers now on the spot would gladly undertake the work for a bounty of one shilling a ton on all the cement stone taken away from the different shoals in the harbour” The good Captain’s suggestion was evidently taken up as a footnote mentions that “…of 530 tons of soil dredged up; 70 tons of this were of cement stone, worth five shillings a ton.

London architect W.H. Lindsey 1851 descriptions of the trade will resonate with many a crew member of a modern aggregate dredger. “……..The cutter rigged smacks would race one another to and from their dredging grounds. Each boat stained every stitch of canvas in the eager endeavour to get into harbour before the rest..…this scene, wind and weather permitting, is constantly recurring, both morning and evening, the stimulus to exertion in the morning being the desire to take up the most favourable position for pursuing their occupation on the dredging grounds….” Lindsey adds that “…dredger-men received from the cement-makers about five shillings a ton…” and that “.....their occupation is, like fishing, precarious, owing to its dependence on the weather. At times however, with a favourable wind for dredging, that is one which will carry them over the grounds, a very profitable day’s work is soon had…” It’s also reported that the Whitstable oyster industry had some hard times, when stock was all but wiped out by disease and hard winters during which ice covered the whole Bay and the Flats. During those hard times, some Flatsmen (freelance Whitstable oystermen) turned to dredging cement stones. “That was unbelievably hard work”. Similarly, the foreshore at Bognor Regis had a cottage industry in natural pyrites, referred to locally as “Picking Mine”. The London Clay outcrop off Bognor extends along the coast from Felham to Pagham where the extreme low water mark is some 600 metres from the shore-line where the receding tide would leave an accumulation of iron pyrites of various sizes in every hollow in the clay’s surface. Before the arrival of the railways, boats containing coal would beach on the foreshore and, when discharged, would require ballast before returning to sea. The pyrites was an available “ballast” material which, for many years, had a re-sale value which benefitted the coal boats and for which they paid the Bogner ‘pickers’ some £1.50 per ton. The Picking Mine hey-days were between 1850 & 1870 and declining with the arrival of the Barnham to Bogner railway branch line in 1864 which eventually ended the arrival of coal by boat. However, by 1890 the industry had died out as Roman cement was replaced by the cheaper chalk based Portland cement.

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