116 SECTIONAL ADDRESSES. 
the King Edward, put on service in the spring of 1901, was the result— 
the first commercial turbine. Before that, however, in 1898, the Parsons 
Marine Steam Turbine Company received an order from the Admiralty 
to build the Viper, whose hull was built by Messrs. Hawthorn, Leslie ; 
and Messrs. Armstrong, Whitworth, on their own account, built the Cobra, 
engined by Parsons. Both of these were torpedo-boat destroyers, and the 
Cobra was purchased by the Admiralty. Most unfortunately, at an early 
date after delivery, through no fault of the turbines, they were both 
wrecked, so that little service experience was available. Both of these 
vessels had four shafts; the Viper had eight propellers, two on each shaft, 
while the Cobra had twelve, three on each shaft. 
The King Edward is so well known that I need only remind you that 
originally she had three shafts with five propellers, two on each side 
shaft, but later, single propellers were fitted to the side shafts. She is still 
running with the original boiler after twenty-four years’ service, four of 
which were spent in war service in the stormy English Channel carrying 
troops from England to France. The engines also are the originals, except 
that higher-powered ‘ go-astern’ turbines have been fitted. 
There was no method of indicating the turbines at that date, and, 
while Sir Charles was able, from theoretical calculations, to give a close 
estimate of the 8.H.P., it was very desirable to get it accurately on trial. 
To measure the torsion of the shaft was the natural way, and we made the 
attempt in the Queen Alexandra, which was put in service in 1902, by means 
of a telephone and contacts on the shafts a considerable distance apart. 
This had been tested on a works shaft at about 200 revolutions with 
success, but at the higher revolutions on the Queen it was not at first very 
successful. Thereafter, an induction method, with permanent magnets and 
coils, designed by Mr. Chas. Johnson, was used for some time with success, 
but when tried in T.B.D.s, with their light and narrow hulls, the very slight 
change of form which sometimes occurred in a sea-way was sufficient to 
upset the arrangement, which depended for its success on a very small 
clearance between the electric coils fixed to the hull and the sharp 
permanent magnets fixed onthe shaft. The Hopkinson-Thring instrument, 
using only a short length of shaft, with mirror and light arrangement, was 
much employed ; and, using likewise a short length of shaft, Edgecombe 
constructed an averaging electrical meter, which had the great advantage 
of requiring only one reading even on a reciprocating-engine shaft. There 
are now several types of meters available which can be used with con- 
fidence ; some such instrument is essential with a turbine, and very 
desirable with a reciprocating engine, whether steam or internal-combus- 
tion. On this subject of indicating engines on trial, several have not only 
had the torque indicated, and hence the shaft horse-power obtained, 
which does away with any question of main-engine friction, but instruments 
have also been devised for giving the real thrust ; from these two readings 
the efficiency of the propeller is obtained which it is so desirable to know. 
Following the King Edward and Queen Alexandra, the Queen for 
the Dover-Calais service and the Brighton for the Newhaven-Dieppe 
service were the first cross-Channel turbine steamers put in service in 
1903. They also were most successful, and the turbine as a commercial 
engine was fairly launched, a great tribute to the genius of Sir Charles 
Parsons and his courage in overcoming the many initial difficulties. The 
