( 201 ) 
Cl, C a, C 3, C4, 05-, Reprefents a Line over 
the Arm of the Gibbet, or rather a Plane goinc^ 
through the Middle of it, in feveral of its Situa- 
^ towards the right Hand, from its 
direct Polition C r. 
C 6, C 7, C 85 Cfy Reprefent the feveral Situations 
of the Gibbet towards the Left, the laft Pulley r, at 
the End of the Gibbet, immediately over the Weight 
traverfing in the Circle y, 4, 3, 2, i, 6 , 7, 8. 
When the Gibbet is in the Pofition c g, the Rope 
runs diredtly over the Middle of its Arm, therefore' 
the lead: Force applied to r or r, can keep in its 
Place the greateft Weight that can be drawn up by 
the Crane, when fufpended to the Ram-head. If the 
Pullies are at p and q, the Gibbet loaded will alfo 
be without Labour retain’d in the Polition C x on the 
Right, and C6 on the Left, and with no great Trou- 
ble in the Polition Ci. 
But if the Gibbet be brought over the Wharf at 
4 on the Right, or at 8 on the Left, the Rope will 
no longer run over the Middle of the Gibbet, but de- 
viate from it, fo as to make with it the Angle ^ 4 
or 8 n, and raife the Weight by the Motion of the 
Gibbet in Proportion as the Line ^ 4, or 8, is longer 
than /-4, or 8 ; and therefore the Weight will tend 
to run back towards g in Proportion to the Difference 
of thofe Lines, which mull give a Twitch to the 
Perfon who draws from r, or r by a guide Rope. 
If to prevent this Inconveniency the Pulley at q 
be remov’d back to Q,, then indeed the Rope will 
run over the Line C 4, or / 4, and confequently the 
Gibbet will be ealily held in that Situation* but if 
you have Occafion to move the Weight to y, the Rope 
E e touching 
