Thomas Martin was, in all likelihood, a Smeatonian, AKA, a member of The Society Of Civil Engineers of London so named for John Smeaton.
I ordered up a copy of The Smeatonians by Garth Watson to see what I could learn of Mr. Martin. Learn something I did, just not much. A Thomas Martin was admitted as a member in 1781, was noted to have attended a meeting in 1789 and was listed in a membership role of 1791 as living in St. Michael's Parish, Cornhill, London.
And that is all.
I've sent emails to both St. Michael's and The Society Of Civil Engineers in hopes of turning up some useful information on the elusive Mr. Martin. After all, he did list London as the place of publication for his tome and it must have taken him some years to prepare the copy.
Even more so, Martin notes that the text is a compilation of information drawn from the works of numerous experts in allied fields. To be a member of a Society would have stood him well, dontcha think?
The research continues. If anyone just so happens to live in Cornhill or is a member of The Society, please don't hesitate to jump in and lend a hand!
Till next, Gary