The family involvement in Robert’s business in 1907 is confirmed by newspaper reports: "R. L. Jones & Company of Delta operate a large quarry in this township [Peach Bottom], which has been in existence for many years ... The firm is composed of R. L. Jones, and his two sons, Arthur and John Jones."
[History of York County Pennsylvania (Vol I), 1907, p 1056] Also, by 1907 Robert’s youngest brother William Penn Jones, was superintending his quarries and his big quarry at Peach Bottom was employing fifty men.
It is likely that poor health was, by then, limiting Robert’s capabilities. This account has highlighted some of the dangers of working in the slate quarries but no mention has yet been made of the hidden danger that caused the deaths of innumerable quarry workers over the centuries.
A daily reality of working in the quarries was slate dust. Area residents recalled that men came home from work so covered in dust that only their eyes remained untouched. (Le Master personal communication 2004). [noted in this series of reports from the "US Department of the Interior National Park Service", Sect.8 p.9]
"Men working slates and exposed to dust arising there from experience an excessive death-rate from pulmonary tuberculosis and other respiratory diseases"[Davies, T. W., Tubercle 1939 Vol.20 pp.543-55 ref.10] Slate contains silica and exposure to its dust can cause silicosis or silica dust-associated tuberculosis. Robert contracted pulmonary TB and was attended by a doctor from July 1906. He died at his home in Peach Bottom Township on 10 February, 1907 and was buried at Slateville Cemetery three days later.
Rev. Griffith Ellis of Bootle wrote in Y Negesydd, 21 Mar 1907 that he had received a letter from "Mr William C. Roberts, West Bangor, Pa, in the United States."
, stating:
We recently had a great loss through the death of Mr R L Jones, one of our elders. He was very devout; and he has left a thousand dollars in his will to the Rehoboth church. There was never a more peaceful and valuable church than that one of which to be a servant or better still a preacher and a shepherd. ... Mr R L Jones was a native of Penmachno. He and his wife and daughter visited this country some years ago; and I had at that time the pleasure of their society. And they showed me great kindness when I visited West Bangor, in 1892.