Intelligence and Miscellaneous Articles. 309 



hand discoveries, in which the noble author is too apt to indulge ; 

 and thouo-h we may readily admit that two water-screws may be most 

 advantageously employed in turning of any water-wheel, where an 

 abundant supply is tound at the top of the machine, it yet reiiuires a 

 greater share of penetration than we choose to take credit for, to 

 discover how a larger quantity of water can descend than has been 

 previously raised ; or, if so, how the machine could be at all applied 

 to the raising of water." 



I am well aware that particulars will often occur to a casual reader, 

 which may escape the studious application of one who is employed in 

 compiling a continued comment on any work. I do not, therefore, 

 quote Mr. Partington's failure, that the contrast may raise the credit 

 of what I have now to suggest. All the conclusion which I wish to 

 draw from it is, that some obscurity evidently exists in the original, 

 which requires elucidation ; and this, I think, may be derived from 

 the established principles of hydrostatics. 



In the same manner that a rotatory motion applied to Archime- 

 des's screw will raise water, so the descent of water down the screw 

 may give it a rotatory motion round its axis. If, therefore, we sup- 

 pose two screws to have a common axis, with their threads winding 

 in contrary directions, the water which descends in one will tend to 

 produce a motion which would raise it in the other. Now let the 

 screw through which the water descends have two threads, while the 

 raising screw has but one : and it is clear (if the bores are the same) 

 that the force of the one will be double that of the other, and that the 

 descending water may consequently turn the " double water- screw" 

 so as to cause "the innermost to mount the water " from the lower 

 level to more than the height from which it has descended in the out- 

 ermost. Even if the friction, inertia, &c. should be greater impe- 

 diments than could be overcome by the given expenditure of water, 

 " a most extraordinary help " might still be obtained "for the turning 

 of the screw " in the proper direction "to make the water rise." 



N. R. L). 



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