400 
weight reduces their price per fathom below that of hempen 
ropes. 
Another important advantage belonging to the wire rope 
is its lightness. In mining and railway operations, the saving 
of loeight is the saving of poicer^ and, in the same ratio, the 
saving of expense ; for several horse power may be saved in 
an engine, by the application of wire rope instead of hempen ; 
and this becomes a matter of much greater moment, if the 
pit be very deep, or the inclined plane very long. On long 
inclines it is especially desirable to curtail weight and friction; 
for there are many planes, which ought to be self-acting^ that 
are prevented from being so by the great weight of the rope. 
Take, for example, an inclined plane 1,000 yards in length. 
A four-inch hempen rope would weigh nearly a ton, while a 
wire rope of equal strength would weigh about 9 cwt. This 
additional weight of hempen rope might, where the inclination 
is small, prevent the incline from working as a self-acting 
plane ; and in the case of an engine plane, the load upon the 
engine and the friction of the sheaves would be considerably 
increased. 
As regards the durability of wire ropes, no very decisive 
opinion can be pronounced in their present imperfect state. 
They are, undoubtedly, capable of much improvement, and 
it is probable that, ere long, their greater economy will be 
demonstrated by their increased durability. 
In their present condition, wire ropes seem well adapted 
for dry, smooth, and easy work ; but for very rough tugs, or 
for wet situations, they are not so well suited. 
They seem also to be more applicable for drawing weights 
along horizontal or inclined planes, than for lifting them 
perpendicularly. 
The diameter of the pulleys and drums ought to be in- 
creased, when wire ropes are introduced, for they cannot be 
coiled round small barrels without injuring the texture of the 
