The main drawing on this page is a study of a palm tree, the uppermost leaves of which continue on the opposite sheet of the double-page spread, see folio 44 (D15378). Turner has also made a small sketch of the detailed texture of the bark.
Cecilia Powell has identified the inverted sketch at the bottom of the page as the arched outlet of the Cloaca Maxima, the great Roman sewer, found near the Ponte Rotto on the eastern bank of the Tiber. Turner may have been familiar with the site from Piranesi’s engravings in Della Magnificenza ed Architettura de’Romani, 1761, but it was also widely noted by travel writers, for example Charlotte Eaton, who described it in her book, Rome in the Nineteenth Century:
Now, all that we see of it is the upper part of a grey massy arch of peperino stone, as solid as the day it was built, through which the water almost imperceptibly flows. Though choked up nearly to its top by the artificial elevation of the surface of Modern Rome, it is curious to see it still serving as the common sewer of the city, after the lapse of nearly three thousand years.1
Today the opening is enclosed within a larger arch, part of the embankment built at the end of the nineteenth century.
Charlotte Anne Waldie Eaton, Rome in the Nineteenth Century, Edinburgh 1820, p.325.