1878.] Superficial Gravels and Clays . 333 
Nearer the river, close to Style Hall, I observed the section 
shown in Fig. 17. 
Near to the place where this section was taken Mr. Crooke 
Ti£. 18 
Section N.W. Corner of Mr. Trimmer’s Old Brick-field. 
a, 1. Brick-clay, removed by Mr. Trimmer. a , 3. Gravel in sandy clay, with some 
dark brown sand at base. c, 1. Curled yellow sand, with fragments of fresh- 
water shells. c, 2. Sand and sandy loam, with thin layers of clay, and some 
small angular gravel and minute fragments of shells. c, 3. Sandy subangular 
gravel. 
found a flint implement which had been thrown out from a 
depth of about 17 feet from the surface. 
Towards the western end of Brentford a very interesting 
series of pits have been opened to obtain sand and gravel. 
They are all on or near to the site of Mr. Trimmer’s old 
western brick-field. Fig. 18 shows the beds exposed in a pit 
near the north-west corner of the old brick-field. 
Section East End of Mr. Trimmer’s Old Brick-field. 
a, 1. Brick-clay, removed by Mr. Trimmer. a, 3. Gravel in clay. c. Layer of 
sand at top ; then 6 inches of grave lin which was a broken valve of Unio picto- 
nrn; then sand and gravel. e. Yellow sand. Unio pictornm and Cvcla's 
rivicola, common. J 
