PRESTWICH WOOLWICH AND READING SERIES. 145 



a doubt. At the>Pentonville Prison the Mottled clay series is 55 feet 

 thick and the Thanet Sands 35 feet. 



Well-section, Hornsey. 



(Mr. N. T. WethereU.) 



Feet. 



Vegetable mould 2 



London clay 138 



I. Basement-bed o/ 1 ^, , , 



the London Clayl) Clay and green sand 2? 



II. & III. Woolwich ,,r J ■■■'.■ '/"'"'",",':.""'". 



and Readina ^°°*^ ^^ imperfect coal {lignite) 4 



(^ . /} '{ Several beds of Plastic clay and sand, and 



Thmet Tands. '^"f' /he last bed above the chalk con- 



\_ sists 01 green sand and pebbles 71 



To the Chalk 225 



Well-section, Colney Hatch Lunatic Asylum. 

 (13th Report of the Committee of Visitors, 1850.) 



Feet. 



T J ni \ b. Brown clay 36 



LondonClay. |^ Blue clay 98 



I. Basement-bed of the j b. Hai'd stone.... 1 



London Clay, Zfeet. \ la. Green sand 2 



■nr 1 • T. J n 7 C c. Coloured clay 8 



II. Woolwich and Read- , r. i i i • i i o 



inn Seriet 27 feet i *' Coloured clay, various colours 13 



ing Aeries, z J feet. ^^ Black pebbles 6 



III. Thanet Sands. Dark grey sand 25 



189 

 Chalk 141 



330 



Well-section, Winchmore Hill. 



(Dr. Mitchell's MSS. vol. iv. p. 59.) 



Feet. 



LondonClay. Blue clay 186 



II. Woolwich and J6. Red clay 36 



Reading Series. \a. Sands and gravel 8 



To the Chalk 240 



The preponderance of green sands in the place of the mottled clays, 

 vphich are so well developed at Tottenham *, is a peculiarity in the fol- 

 lowing section, a. and b. ii. may possibly belong to the Thanet sands. 



Well-section, Waltham Cross. 



(Mr. R. W. Mylne.) 



Feet. 



Mould 2 



Loam 4 



Gravel 7 



Gravel, very rough 3 



Carried forward 16 



* " Geol. England and Wales," note, p. 24. 



