The most definitive replication attempts were performed by Sir Charles Algernon Parsons. A prominent scientist and engineer known for his invention of the steam turbine, he spent about 40 years (1882–1922) and a considerable part of his fortune trying to reproduce the experiments of Moissan and Hannay, but also adapted processes of his own.[16] Parsons was known for his painstakingly accurate approach and methodical record keeping; all his resulting samples were preserved for further analysis by an independent party.[17] He wrote a number of articles—some of the earliest on HPHT diamond—in which he claimed to have produced small diamonds.[18] However, in 1928, he authorized Dr. C.H. Desch to publish an article[19] in which he stated his belief that no synthetic diamonds (including those of Moissan and others) had been produced up to that date. He suggested that most diamonds that had been produced up to that point were likely synthetic spinel