( >94 ) 
Wardy W tilt am Hogg^ y . Dod^ Charles 
Finch ^ D. D everts William Jones^ 
King’s Officers at Sheernefs and Chatham. 
IV. Somz Ohferyations on the Crane, with I?n- 
proVemeuts on that Machine^ by J. T. Defagu- 
liers, F. ^ S. Sheivn the Society in Models , 
but here exemplified by Figures^ 
T he Crane is an Inftrument fo much ufed, and 
fo well known, that it wou’d be needlefs here 
to give a particular Defcription of it ; but as there 
are feveral Sorts of Cranes, and as that Machine is to 
ferve for different Purpofes, I wou’d only fhew what 
kind of Crane is inoft proper for any particular 
Work and how to prevent thofe Accidents which 
daily happen through the Carelefnefs of common 
Labourers, to the damaging of Goods,, and often the 
wounding, or killing of the Men. 
When great Weights are to be rais’d from a. great 
Depth, and laid on Carriages very near the Precipice, 
as at the Edge of a Stone Quarry, the Crane muft 
be a fix’d one, and only the Gibbet moveable, from 
which the Weight hangs,, as in Fig. i. Here, in the 
common Way, the Rope Rrr, or Chain, which runs 
over the Gibbet, goes between two Pullies P,Q,, fixed 
within the upper horizontal Beam of the Crane 
AQ^TX, above the Axis of the Gibbet BGV, fo 
as to be carried eafily to the Right or Left Hand, 
from W to when the Gibbet turns upon its Axis 
to bring the Burthen over the Carriage defign’d to re- 
ceive 
