EXCAVATION OF SMALL PITS. 333 



was then generally left ; being not deemed worth the great labour 

 of throwing it up so high. The overlay being there 4 feet thick, 

 the extreme height to raise the marl was 12 feet from the bottom 

 of the marl to the surface of the ground where the carts were 

 loaded. 



In this manner of working, were successively uncovered and 

 excavated the next ranges, B B and C C. But before either range of 

 marl was near being finished, the removal of the next succeeding 

 overlay had been begun and was extended at convenient times, and 

 especially when the wet or frozen condition of the land forbade 

 most other farm labours. At such times, the worst previous 

 weather but slightly impedes the uncovering of marl ; and thus a 

 large proportion of this heavy labour has been performed when 

 scarcely any other farm work could be done. This circumstance 

 greatly diminishes what would otherwise be the expense. 



The digging of the first marl (1 in A) was begun on June 28th, 

 1844. The excavation of the third range of pits, CC, was finished 

 the following April. This kst range was 250 feet long, 15 

 feet wide on an average ; and measured 25,800 cubic feet in the 

 bed (allowing a proper deduction for lost walls and bottoms), which 

 would expand to about 29,670 heaped bushels after being dug. 



The separate pits of the wider and more regular range C C were 

 much longer, as well as much wider, than those of the earlier ranges. 

 They were the full width permitted by that of the uncovered marl, 

 clear of the narrow drain on the land-side, and the wall left on the 

 opposite side or about 13 feet. In length, they were 15 to 20 

 feet, or more, to suit the amount of labour engaged. In the 

 usually dry weather of summer and autumn, and even in winter 

 when a strong force was employed, there was the less danger of 

 having unfinished work suspended by rain, and lost by overflow 

 of water, or caving earth ] and then larger diggings were opened. 

 By increasing the size of the pits, there was the less trouble in 

 constructing new drains, less loss in the dividing walls left, and 

 more space and convenience for the pit-men. Besides, there was 

 the benefit of equalizing the labour of throwing out the marl, by 

 keeping the digging on two different levels at the same time. 



The still slightly increasing thickness of the overlying earth 

 made that of the next range (D) 5 feet ; to which height, of course, 

 the marl was thrown from the pits of C, making the perpendicular 

 height from the top of the marl 5 feet, and from the bottom, 13 

 feet, when all was dug; or 12 feet when the stony bottom layer 

 was left, as was now usual. But to make sure of the thrown marl 

 not falling back into the pit, and especially when there was some 

 quantity of marl remaining in the pile in advance of the carting, 

 the height of the pit-man's cast was necessarily considerably more 

 than the mere depth of the then excavation. Added to this was 



