CALCAREOUS MANURES— APPENDIX. 



309 



Note X. — Extension of suhinct from page 150. 



A BIACHINE PROPOSED FOR RAISING MARL. 



The machine which will be described below is used at Fortress Monroe 

 for raising sand from the fosse to fill the ramparts; and has been found by 

 experience to be the best contrivance of all which have been tried for 

 that operation, and for which an immense amount of labor was necessary 

 in constructing the defences of the fortress. Precisely the same manner of 

 operation is required for raising marl from deep pits, and there can be no 

 doubt of this being a more eflective machine for that purpose than any 

 heretofore applied. The force applied is the weight of the laborers, on the 

 principle of the tread-mill, which is the most effective manner in which the 

 power of men can be applied. I am indebted for the suggestion of this 

 machine for raising marl to the observation and scientific knowledge of 

 mechanics of my friend M. Tuomey, and also for the following description 

 and the drawings for the engraved figures. Mr. Tuomey, when making a 

 transient visit to the fortress, had seen the machine at work; and recently, 

 after reading in the foregoing part of this work the remarks on the differ- 

 ent modes of raising marl, and having witnessed some of the usual modes 

 in practice, this machine and what he liad seen of its power appeared 

 greatly superior, whenever circumstances may require any use of ma- 

 chinery. Upon being thus informed, I applied to Dr. Robert Archer, U. 

 S. A. Surgeon at Fortress Monroe, (to whom I, and through me the agri- 

 cultural public, have been frequently and much indebted,) for a rough plan, 

 and accurate statement of the dimensions of the machine, both of which 

 he kindly furnished ; and with the aid of these, Mr. Tuomey has been ena- 

 bled to give such particular description and correct delineation as will 

 serve for full instruction for the building and working of the machine. 



Mg. 1. 



" 1. Figure 1 is a side view, in perspective. 



i, i. The base, consisting- of 3 pieces of scantling, each 12 feet long, and 11 inches by 5, 

 notched on to each other about 6 inches from the end, so as to be flush on top, form- 

 ing an equilateral triangle. 



e, The principal post 8 tout, 8 by 6 inches, secured to the base, and braced by the 

 braces y: Near the top of this post 2 iron sheeves or pulleys pre placed, one on each 

 side, and secured by pieces spiked over them. The chains pass over these pulleys. 



/, 2 braces 11 feet long, 4 inches by 6. 



h, h, Two uprights, in which the gudgeons of the wheel turn, they are bolted to the base 

 and connected at top by the piece g, 10 feet 6 inches long, 4i by 6 inches, which also 

 serves as a handrail for the men to steady by when working on the wheel. These 



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