proved to be a success, and in 1777, ships sailed out of the harbour carrying 80,000 tonnes of coal, 300 tons of salt and 1.75 million glass bottles. The coal was brought to the harbour from nearby collieries via wagonways, with coal wagons being drawn by horses. Salt continued to be exported from Seaton Sluice until 1798, when a new salt tax put an end to the trade. The bottleworks In 1763 Sir Francis Blake Delaval (1727–1771) obtained Parliamentary approval to develop 10 hectares of land at Seaton Sluice as glassworks. The works was known as 'The Royal Hartley Bottleworks'. Sir Francis needed skilled glassmakers, and his brother Tom Delaval brought skilled men from Neinberg, in Germany, to train the local men in glassmaking. The works used local materials: sea sand, sea kelp, clay from the links and local coal. The glassworks expanded with time and eventually had six large cone-shaped furnaces which dominated the skyline; they were given the names: Gallagan, Bias, Charlotte, Hartley, Waterford and Success. The three larger cones were tall. In 1777 production reached 1,740,000 bottles per year. Bottles were sent down to the harbour via narrow gauge railways running through tunnels. The tunnels were used as air-raid shelters during the Second World War. The bottles were carried to London on 'bottle sloops', slightly smaller than collier brigs, about long. A distinctive feature was that the main mast could be lowered, allowing them to pass under the arches of old London Bridge. A bottle sloop would make one round trip to London per month, as did the collier brigs. Bottles were also exported to Europe. The bottleworks were so large that they contained a market place, a brewery, a granary, a brickyard, a chapel, shops, public houses and a quarry. The workers lived in stone-built houses in several streets around the bottleworks. In 1768 a shipyard was established. Competition from other glass-making centres led to a decline in orders and the bottleworks closed in 1872. The last bottles to leave were on the 'Unity of Boston', bound for the Channel Islands. A few years later, in 1896, the cone-shaped furnaces were demolished and replaced by houses. Nowadays there is hardly any trace of the original bottleworks. Decline of the coal trade Even with the harbour improvements made by the Delaval family, the harbour was still limited in the size of ships that it could handle. Meanwhile,