842 GRADUATED PITS. 



marl it for $2, And, therefore, deeming tlie omission or delay of 

 marling to be by far the most expensive thing in regard to the 

 operation, I marled even in unsuitable seasons, so as to avoid the 

 necessity of ever again bearing the much heavier loss of cultivating 

 any unmarled ground. 



Excavating Marl in large graduated pits 



The excavation of the range of perpendicular pits C (Fig. IL), 

 was finished in April, 1845. The marl carried out from that and 

 the two previously worked ranges, A and B, amounted to 71,541 

 heaped bushels according to the number of loads counted on the 

 fields, and their estimated quantities. Previous to beginning to 

 work at this digging, there had been carried out from another, not 

 far off, 26,600 bushels, from January 24th, 1844, to June 28th, 

 the time of beginning the second excavation. Of the earlier job, 

 it is enough to say that it was very laborious, owing to the overlay 

 to remove, of 7 to 8 feet, which was double the thickness of the 

 marl below. This, my first excavation here, was worked upon the 

 plan I had used elsewhere ; the carts descending by a gently graded 

 slope to the bottom of the marl. But every considerable rain caused 

 the loose sand and gravel to fall in and choke the small drain cut 

 around on the top of the marl, and then the spring and rain water 

 flooded the pit j the bottom of the digging (when deep) being lower 

 than any outlet for the water. The many such disasters which 

 were suffered and repaired, and the consequent losses of time and 

 labour, induced me, for the next work, to pursue the more laborious, 

 but less hazardous plan of excavating by small perpendicular pits, 

 as described in the foregoing pages. But after thus working out 

 the ranges A, B, and C, I thought that with my then better expe- 

 rience, and by using better safeguards than before, I might venture 

 to return to the plan of graduated excavations. With this inten- 

 tion, the range D (Fig. II.), had been laid off, and cleared of its 

 overlay, during the winter and spring of 1845, at my leisure and 

 convenience, while the latter excavations of the range C were still 

 in progress. The same plan has been since continued, with im- 

 provements, for the successive and adjacent ranges, E, F, and Gr, 

 which last is not quite exhausted of its marl, at this time (October 

 1849), and another range, H, has nearly been cleared of its over- 

 lay, and made ready for its excavation to be begun. It will be 

 unnecessary to keep separate the incidents of these different large 

 workings, when referring to such processes as may be deemed worth 

 being mentioned. The natural features continued the same as to 

 the marl, and also of the overlay, excepting its increasing in thick- 

 ness, as the distance from the stream was extended. The different 

 means used for saving labour were mostly adopted in the working 



