|Date||22 April 2011|
|Location||Moel Faban, Bethesda||SH 63146 67698; 53.18870°N, 4.04970°W|
A rock cannon was a traditional pyrotechnic device fired to mark special occasions and celebrations. Their use is thought to date back to the mid 18th century and they were popularly employed in festivities in quarrying areas in the 19th century.
A cannon comprised a boulder or rocky outcrop into which a number of holes had been drilled. Each hole was normally around an inch across by five deep, and was linked to a neighbouring one via a shallow channel cut into the surface of the rock.
Preparation for firing was as follows. A black powder-filled goose quill fuse slightly shorter than the depth of the hole was first of all placed in each hole. The holes were then filled with black powder to a third of their depth and packed with crushed rock stemming almost to the top. Once the holes had been charged more black powder was laid over the fuses and along the interconnecting grooves. Finally, these channels were covered with more stemming in order to slow down the burn rate of the fuse train.
The use of channels between the holes was a later innovation. In earlier cannon, goose fat spread on the rock surface and sprinkled with black powder was used to connect the holes. Where available space meant that the distance between the holes was inadequate, curved paths were employed in order to increase the delay between successive detonations.
The orange flashes and resounding thunder of a cannon in operation are said to have been rather marvellous.
Cannonading played a central role in the celebration of special events. Typical 19th century festivities also featured decorations and activities such as floral arches, flying of flags and banners, bands playing, bonfires and fireworks, and special teas and lunches. The type of events celebrated in this fashion ranged from comings of age and marriages amongst the local gentry to saluting visiting dignitaries and marking national occasions such as royal weddings, coronations and jubilees.
For very important celebrations multiple cannon sites in a locality were employed, with volleys from those in one quarry being answered by those in the next, setting up a reverberating thunder amongst the mountains.
Accidents causing serious injury when preparing or firing the cannon were not unknown.
Their use continued on into the early 20th century, marking such national celebrations as the end of the Boer War (1902), the coronations of Edward VII (1902) and George V (1911), and a visit by the Prince of Wales (the future Edward VIII) to Blaenau Ffestiniog in 1923.
Cannonading also took place in Blaenau Ffestiniog on several occasions in the 1940s and 50s, but with the traditional cannon replaced by a more modern equivalent. On disused quarry waste tips a series of sticks of gelignite were laid on slate slabs with the ends of their fuses lying in the channel of tram-road rails laid end to end. A line of black powder was laid along this channel to connect the fuses together. One particular event marked in this way was a visit in 1949 by Princess Elizabeth and the Duke of Edinburgh.
Griff R Jones (2002) has documented 235 individual rock cannon sites in the slate quarrying areas of Gwynedd. The number of cannon holes ranges from 1 to 195, with the average being 26.
Reference: Griff R Jones, The Rock Cannon of Gwynedd, 2002 (ISBN 0953369218)