Some nicely obscure titles in full view on Google Books: A Description of the Patent Thermosiphon with some modes of applying it to horticultural and other purposes; and Tables for Facilitating Arithmetical Calculations Intended for Calculating the Proportionate Charges on the Parishes in Poor Law Unions. Both are by Thomas Fowler, a printer, banker and self-taught mathematician from Great Torrington, Devon, where he lived all his life.
Fowler was also an inventor, whose "thermosiphon" was a convective central heating system. It worked well, and was well-publicised (see The Gardener's magazine and register of rural & domestic improvement, Volume 5 and The Edinburgh journal of science, Volume 1, both 1829). Unfortunately he didn't make any money from it due to the patent system of the time, which allowed minimal changes without breaching patent, and the idea was pirated.
As Treasurer of the Poor Law Union, his work involved repetitive calculations, typically involving ratios of sums of money. In sterling currency, this involved converting £sd into an integer number of farthings, doing the ratio, then converting back. Fowler's Tables for Facilitating Arithmetical Calculations ... etc outlined a scheme for simplifying these calculations by converting them into a different number base. A mechanical digital calculator was the next step, which he created but again didn't lead anywhere: according to some accounts, the government were so fed up with the Charles Babbage saga that they didn't want to hear of any more calculating machines.
Nothing survives of the calculator except a representation in a stained glass window in St. Michaels Church, Great Torrington. However, it has been reconstructed by Mark Glusker based on a description discovered by researchers Pamela Vass and David Hogan. See The ternary calculating machine of Thomas Fowler. There's a paper about it (not online): The Ternary Calculating Machine of Thomas Fowler, Mark Glusker, David M. Hogan, Pamela Vass, IEEE Annals of the History of Computing, Volume 27, Issue 3, July 2005, pp4-22, ISSN:1058-6180.