Memorials of Old Northamptonshire (1903), a book edited by Alice Dryden, includes an entire chapter by M. Jourdain about Thomas Tresham’s Triangular Lodge. Descriptions of the building usually skate over the Catholic symbolism encoded in its structure but Jourdain goes into some detail describing the many inscriptions and numerological details. The engraved illustration is rather good as well, although it makes the lodge appear a more squat than it should be. The chapter also contains a description of further symbolism at Tresham’s Lyveden manor. Read it here.