The images in this post are taken from a report in the Wrexham newspaper The Leader, on 13th February 2019 by Jamie Bowman. No copyright infringement is intended.
Thomas’ employer Henry Breyer Robertson owned or part owned a number of industrial, mining and rail enterprises over a wide area. Thomas’ sons Thomas Alexander and William were given clerical employment in the Plas Power works. H. B. Robertson’s uncle, Mr Dean, obviously had influence in the Minera Lime works, in the same area. In 1892 Mr Dean invited Thomas to view a newly discovered cave at the works.
Wednesday the 27th I left here by the first train for Minera. On arriving at Plas Power station I first went to see Tom who was in bed with the measles since Saturday. Mr Dean kindly had his trap in waiting for me to take me to Minera. He asked me to go to see the recently discovered cave there, from which he sent me the stalagmites. He said he would send the trap to meet me. I was sorry Tom was laid up, and he was very sorry too, for he would have liked to help me in any way. I was much interested in what I observed all the way to Minera. I passed near a coal pit, and the village. I saw Minera Church; a nice one it is. Minera Hall was close to the roadside; a moderate sized place.
I got to the Lime Works at twenty minutes to eleven o’clock. On getting to the Office, Mr. Lewis the Secretary, and his clerk, Mr. Wilkins got ready to go over the works with me. They first took me to the stone crushing mill: here the limestone is prepared for road metalling and for glass works. It was a noisy and dusty place, but of much interest. I next inspected the lime kilns: there are two large buildings on the Hoffmann principle. The buildings are in the form of a long square with the circular ends. The chambers in which the limestone is burned, are arched over all round the sides of the buildings and the doors are bricked up until the operation is over. The fire never dies out but it keeps travelling from one chamber to another all the year round; small coal (slack) is introduced into the chambers by means of iron tubes so as to feed the fire. There is a huge chimney to one of the kilns; it is 225 feet in height, by 15 feet in diameter. The kilns cost the company £20,000 to construct, but they can turn out an unlimited quantity of burnt lime.
Our next move was to the cave; it was not very inviting, but like an man of science, I wished to explore it. Mr Lewis got me leggings to cover my legs, and coat to cover my body, so as to keep me clean. I doffed my own coat, and with a lighted candle, I followed Mr Mr Lewis and Mister Wilkins into the cave. I had to lie on my right side and drag myself down slope, with scarcely enough room for me to wriggle through. After a few yards of this, I got to a wide passage where I could stand nearly upright. I was then conducted into a large chamber, long and wide and with a lofty roof. Numerous stalactites were hanging from the roof; they were long tubes of transparent calcite. Pillars of stalagmites word dotting the floor, and most of the floor was covered with thick stalagmitic crust. The floor was uneven and slippery, being here and there composed of soft red earth.
I was next taken to another large chamber, but to get to it I had to clamber on my hands and knees over the wet clay floor. In addition to the usual stalactites and stalagmites, the walls of this chamber one much encrusted with stalactites which oozed from the rock. We returned to the entrance to the first chamber and turned to the right where we got to a large chamber by again crawling over the wet rough floor. This was very uneven, the floor sloped much, and was nearly all covered with a thick stalagmitic crust. From this we went up an narrow flue-like passage on hands and knees into a large space with very lofty roof and the floor much encumbered with fragments of rock. There were a good pillars of stalagmites, and a tiny stream flowed over a gravelly bed on one side. The cylindrical tubes of calcite fell from the roof in hundreds in each of the chambers and got firmly fixed in the stalagmitic floor. It was a rough place to explore and our heads received many hard knocks, but the air was nice and cool. There is a great depth of stalagmite and clay all over the floor of the cave, and the whole bears the impress of great antiquity so that if properly explored, important scientific results might be attained. The entrance is too difficult at present, and it would be expensive to widen it. It was quite accidentally discovered when some rock was taken away.
The Minera site is now owned by the North Wales Wildlife Trust to be used as a nature reserve.