Kennal Vale gunpowder factory started production about 1812 and was immediately commercially sucessful. 1844 the factory expanded and by 1860 it was employing about 50 men. The invention of gelignite and dynamite in the 1880s made the closure of Kennall Vale gunpowder works difficult to operate profitably and it finally closed about 1914
The gunpowder works were located here as the power to the powder mills was by water wheels. The vertical mill stones were housed in each building either side of the water wheel. The water wheel was mounted in the center of the building and was supplied via a leat to a over shot water wheel.
The wealthy owner of the Kennal Vale Gunpowder Mills in Ponsooth was Benjamin Sampson who had been a carpenter at the Tresavean Mine in Gwennap and later a clerk in the Perran Foundry at Perranarworthal. He took over the Kennal Vale mills in 1811.
From Penaluna's Survey:
"In Kennal Vale are gunpowder mills belong to Messrs. Sampson and Co. Here are situated water-wheels constantly employed, two of which keep 14 tons of marble constant by turning, making four to five thousand barrels of gunpowder annually."
However, it was reported on May 18, 1838:
"A most dreadful explosion occurred at the Kennal
Vale gunpowder mills on Thursday morning the 10th instant. Five mills blew up
in succession, and part of a roof was found a mile from the premises. The reports
were most
terrific and created the greatest alarm over an extensive tract of country.
Nothing so severe ever happened at these mills before, though we are happy to
state, there was only one man very seriously injured, and hopes are entertained
for his recovery."
" At a few minutes after eight o?clock on Monday morning the village of Ponsanooth, near Penryn was suddenly thrown into a state of most painful excitement by the loud report (heard for miles around) of an explosion at the Kennal Vale Gunpowder Company's Works. Within a very few minutes the entrance gates of the factory were besieged by a large crowd, all anxious for information, and dreading that the news would be of the most sorrowful kind. As the explosion occurred just before the men left for breakfast it was feared that there had been great loss of life. As the villagers congregated women shrieked and fainted and children cried bitterly. It was, however, quickly ascertained that only one man had been killed and one other injured. At seven o'clock in the morning the men had resumed work, operations having been suspended since one o'clock on Saturday afternoon. At 8.5 a.m. all were startled by a loud report. Upon the manager hastening to the factory, he found that a serious explosion had occurred in the upper presshouse, a building used for compressing the powder into cakes by hydraulic power after it has been received from the incorporating mills, and before it is sent to the granulating house to be broken into grains. This house was utterly demolished. Only one man, William DUNSTAN, was known to be at work within the building at the time of the explosion, and another James PADDY, was engaged with a horse and cart taking powder to and from the building. Paddy was found lying in a water-course about fifteen yards from the front of the building. He was considerably burnt about the face and hands, was badly cut about the head, and had his right leg and right arm broken. Perfectly conscious when found, he stated that he had backed his cart to the door of the house for the purpose of discharging some gun-powder dust in barrels which he had brought to be pressed. DUNSTAN was within the house and about to receive the powder form him when he (Paddy) saw a flash and remembered no more. At first no trace was found of the poor man Dunstan, but very soon afterwards a leg was discovered about five years from the house, and the remainder of his body under a bank on the further side of a road, some 30 years from the building. Of course, life was extinct. The cart standing in front of the building was much damaged, and with the horse had been apparently blown to some little distance. The horse was much singed, but with the exception of a slight cut from a splinter of glass, appeared to be otherwise uninjured. Some of the other buildings in the vicinity were damaged by the slating being shaken off by the concussion, and window sashes, &c, blown in, but beyond this the remaining buildings of the factory were uninjured. Nor would the explosion have communicated to any of them. At present no one is able to assign any cause for the explosion. Dr. BLAMEY of Penryn, was soon in attendance upon Paddy, who by his direction was removed to the Cornwall Infirmary at Truro, and there is reason to hope that he will recover. William Dunstan has unfortunately left a widow and a family of nine or ten children. Every precaution was taken at the works to reduce the risk of danger to a minimum.
THE EXPLOSION AT KENNAL VALE. On Tuesday afternoon at Ponsanooth, an inquest was opened before Mr. Coroner CARLYON and a jury, of which Mr. T. ODGERS was foreman, touching the death of Wm. DUNSTAN. On the facts being made known to the coroner, the Home Office was communicated with, and Major CUNDILL, Royal Artillery, Her Majesty?s inspector of explosives, was immediately sent down. Major Cundill travelled from London by the night mail, and on Tuesday morning made an inspection of the demolished building in company with the coroner. On arriving at the place where the inquest was held, Mr. Carlyon, addressing the jury, said:- Before I swear you I must inform you that you must all attend here again on Thursday morning, at eleven o'clock. The fact is that Her Majesty?s inspector of explosives is not quite prepared, from the examination he has made, to come to any decided opinion about the cause of the accident. He wants to prepare himself further, and that he will do it in time for Thursday. To-day the body will be identified, and we shall adjourn to hear the evidence of the witnesses on Thursday. The jury were then sworn, and went to view the body, which lay in the house adjoining. Thomas Grose then formally identified the body as that of William Dunstan, who worked at the powder mills. The Coroner ? That is all we shall be able to do to-day; I must bind you over to appear here again on Thursday.