CHAPTER XXIX. 



DETAILS OF ACTUAL AND EXTENSIVE MARLING LABOURS. 



THE largest known uncovering and excavation of marl is that 

 which was begun by me in 1844, soon after my resuming marling 

 labours in a new locality, and under new circumstances ; and which 

 work was in progress to 1850. This work is deemed worthy of 

 being particularly described, for the extent and the mode of opera- 

 tion ; and still more because some or all of the same general features 

 of the locality, and advantages and difficulties, belong to very many 

 other situations, of low-lying marl. It will not be my aim, in this 

 place, to describe the general character or to note differences of the 

 extensive marl formations of the Pamunkey river ; but to state 

 minutely the particular conditions of this one locality, and the 

 labours there actually performed. 



The place is on the Newcastle farm, belonging to Carter Braxton, 

 Esq., and adjoining my own. The ground is part of a long and 

 narrow stretch of the lower and more sandy land of the broad 

 flats bordering the Pamunkey. The surface soil, covering the dig- 

 gings to be described, is nearly level, but gradually rises, and the 

 earth overlying the marl increases in thickness from 4 feet, in the 

 earlier work, to 6 at its greatest present enlargement. The sur- 

 face of the bed of marl is also very nearly horizontal ; and the vari- 

 ations from the level do not. agree with those of the surface soil. 



The marl originally was here exposed to view by being partly 

 cut through by a narrow gully conveying a small stream ; which 

 stream received all the drainage of the adjacent land, and thereby 

 was subject to be swollen by heavy rains. The stream, naturally, 

 was about 2 feet below the highest exposed marl, and about 4 feet 

 above the bottom of the bed at the same place. Except the con- 

 tinuation of this stream, and the narrow ravine conveying it, which 

 very gradually descended to the river, all the adjacent ground 

 was at least four feet higher than the upper surface of the marl. 

 The annexed figure will show the profile of the different layers, at 

 the distance of 40 to 60 feet from the stream. 



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