Interestingly, Charles Mackay, the author of Extraordinary Popular Delusions and the Madness of Crowds, was himself one of the most ardent cheerleaders for the Railway Mania [0] "urging people to put their money into the railways and pooh-poohing those who were concerned." and "He had become famous by mocking the bubbles of the past - but had rather less to say about the far more serious bubble that he himself had helped to inflate."[1]

[0] https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1927396

[1] https://www.bbc.com/news/business-51311368