“The New principles is [Langley’s] most important contribution on the subject of gardening. It is the culmination of both his work at Twickenham Park for Thomas Vernon, and his brief directions for ‘arti-natural’ design published in Practical geometry (1726). As such it places him among the earliest exponents of the new style of irregular gardening... If the text of New principles is derivative its plates are the opposite. Inventiveness runs rampant in his designs for serpentines; he ‘confounds, surprises, varies and conceals the bounds’ beyond Pope’s wildest dreams. [...] The garden is not the only arena for Batty’s wanton, ‘arti-natural’ lines. He recommends them as ‘exceeding beautiful in building, as in cielings, parquetting, painting, paving, &c. This, in 1726 (sic) is well in advance of Hogarth’s Line of Beauty and must be regarded as a first step towards the rococo style in England, a style to which Langley had a natural and lasting affinity.” - Harris & Savage, British Architectural Books and Writers, pp. 262--3.