2 Scientific Proceedings, Royal Dublin Society. 
estimated at 64 tons to a square inch. The loss of power in 
transmitting power by wire rope a distance of 150 yards has been 
estimated at 24 per cent. There are also several cases on the 
Continent where a considerable head of water can be obtained, 
where high-pressure pipes are laid, and the water passing through 
these work hydraulic engines. 
The transmission of power by wire ropes was very convenient, 
also working agricultural machinery, such as steam ploughs, &e. 
Ropes running at high speed were extremely convenient for 
working overhead travelling cranes, and also travelling jib cranes. 
The motion in these cases was transmitted by a cotton rope to a 
shaft running through the pillar of the crane, and a set of friction 
wheels gave the means of lifting or travelling the crane. 
- Probably the most beautiful modern means of transmitting 
power is by water, by means of the hydraulic machinery intre- 
duced by Sir William Armstrong. Although the first idea 
occurred to Sir W. Armstrong about ten years before, the first 
hydraulic cranes were adopted for railway stations (for which this 
kind of power is especially applicable) in 1848, in the Trafalgar 
Station in Newcastle by Mr. Harrison. In Sir Wiliam Armstrong’s 
hydraulic system, in order to obtain the necessary pressure to 
work the machinery, a contrivance called an accumulator is used 
(first adopted in 1850 on the M.S. & L. New Holland Station on 
the Humber). This consists of a cast-iron cylinder, which is 
fitted with a ram or plunger, which is loaded with a considerable 
weight to give pressure to the water, which is forced into it by a 
steam engine. By this means a head of from 600 to 800 feet of 
water can very easily be obtained, and the cranes, &c., are in this 
way very much simplified. The hydraulic power is transmitted 
through very strong pipes to the various machines which are to 
be worked by it. These are extremely various. In railway 
goods stations cranes, hoists, capstans, traversing-tables, and turn- 
tables are worked in this way. Excellent examples of this 
machinery may be seen at the London and North-Western North 
Wall Station, and a very large quantity of hydraulic machinery 
will be erected in the course of this summer by the Great Southern 
and Western Railway at the North Wall. A fine application of 
hydraulic machinery is to be seen in the Liverpool corn ware- 
houses, where the corn is lifted from the ship and distributed 
