From what I am aware of, he and his colleagues were among the very first to achieve success with time travel in both directions (although of very limited ranges of approximately 40 years, more or less). There are very inadequate records regarding their collected project data, their equipment, and so forth. However, enough does exist, even 200 year later, to validate his work at least to some degree of authenticity. For example, some of his/their research was prerequisite for future work in this field, and as such, proves his validity to some extent most assuredly (Our base models utilize the same basic principles, however much more advanced). Now, to fully express the fundamental processes required to achieve any lengthy range of reverse time travel which also allows for a forward retrograde of the same, in order not to die or lose valuable collected data, the scientist must utilize a large facility with a full staff of scientists. This sort of thing is not achieved by a small number of people and a simple machine. It simply does not work in that fashion.
Tr. Jameson and Co.