William Wrighte, Grotesque architecture; or, rural amusement (1815)
“ Elevation of a rural grotto (see the plan, plate xii.) which should be built of large rough stones rudely put together, so that the building may as near as possible imitate the beautiful appearance of nature. If the dome was to be richly ornamented with pendentive shell and frosted work, it would look very elegant. In the middle niche is Neptune on a rock, pouring out water, which descends under the pavement through an arch, and forms a running stream. ”
