C 4-96 ] 
The pullies arc here placed in each -block in two 
tier; ieveral being upon the fame pin as in the fir ft 
method, and every one having another under it, as in 
the fecond ; as aifo that, when the tackle is in ufe, 
the two tier, that are the remoteft from one another, 
am fo much larger in diameter than thofe that are 
neareft, as to allow the lines of tire former to go 
over the lines of the latter without rubbing. 
From this conftrodtion arifes a new method of 
new method of reeving the line upon the fliieves : 
For here let the number of thieves be what it will, 
the fall of the tackle will always be upon the middle 
thieve, or on that next the middle, according as the 
number of pullies on each pin is odd or even. 
To do this, the line is fixed to fome convenient 
part of the upper block, and brought round the mid- 
dle fhieve of the larger tier of the under block, from 
thence round one of the fame fort next to the centre 
one of the upper block ; and fo on till the line comes 
to the outfide fhieve, where the laft line of the larger 
tier falls upon the firft fhieve of the fmaller, and 
being reeved round thofe, till it comes at the oppo- 
fite fide, the line from the laft fhieve of the fmaller 
tier again rifes to the firft of the larger, whence it is 
conducted round till it ends on the middle fhieve of 
the upper block on the larger tier; as will appear 
more plain, by infpeeftion of the figure annexed. 
In this method all the lines are clear of one an- 
other, and the blocks are kept parallel. The model 
which I have the honour to fhew the Society, and 
from which I made the draught, is a compofition 
of 20 fliieves, five on each pin. With this model, 
which may eafily be carried in the pocket, I have 
raifed 
