( ^97 ) 
there is only a Catch (as EKx^, Fig» s-) to ' hold 
the Burthen at the Height it is brought up to, whilft 
the Crane is turn’d round in .order to have the 
Weight lower’d into- the VelTcls, which' is done by> 
lifting up the Catch, and being ready to let it dowiil 
again as Need requires. Sometimes an half Cifcumfe-* 
rence of Wood (DIIB,' 5*. ) is held hard againft 
a wooden Wheel W w, on the Axel, to regulate and 
govern, the Defcent of the Weight. But, as in ‘either 
of thefe Cafes, if the Man, at the Crane is. careiefs, 
very bad Accidents happen, Mr. Padmore^ Mr/ 
Ellen's chief Work-man, has made fuch a Contri- 
vance, that the Pali or Lever whereby tlie Axel is 
prefs’d to dired the defce.nding Motion, does fo com- 
municate with the Catch, that in Cafe the Man that 
ought to manage it, fhou’d’carelefly let it go,., the 
Catch always takes, and thereby all Accidents are 
prevented , as will be fliewh in the Explanation of 
the 5th and 6th Figures. . . , 
Where Goods are to be rais’d high, as in unloading 
Vellels, and alfo to be let down deep, as in loading 
them ; (that is, where both the former Operations 
are to be perform’d ) if the Weights do not exceed 
two or three Ton, and many Hands are not to be 
had, then an endlefs ‘Screw turn’d by an Handle at 
each End ( in an oppofite Situation, or with one 
Handle and a Balance to it) leading an Axis in Pe- 
ritrochio, or as it is commonly call’d, a Worm and 
Wheel applied to a Crane, with a Gibbet, is moft 
ufeful : For the Teeth of the Wheel are pull’d by 
the Weight fo diredly againft the Thread of the 
Worm in its Endeavour to defeend, that one may leave 
the Handle in any Pofition where it will flop, with-' 
out 
