580 TRANSACTIONS OF SECTION G. 
Parsons type are employed, the total horse-power being more than three 
and a half millions. In the Royal Navy every new warship, from the 
torpedo-boat up to the largest battleships and armoured cruisers, is fitted 
with turbine engines; and the performances of vessels which have been 
tested on service have been completely satisfactory, in many instances sur- 
passing all records for powers developed and speeds attained. In the war- 
fleets of the world this example is being imitated, although in some cases it 
was at first criticised or condemned. In the mercantile marine as a 
whole, while the new system has not made equal advance, many notable 
examples can be found of what can be accomplished by its adoption. It is now 
admitted that steam turbines enable higher speeds to be attained in vessels of 
given dimensions ; and in steamers built for cross-channel and special services, 
where high speed is essential and coal consumption relatively unimportant, 
turbines have already ousted reciprocating engines. For oversea service and 
long voyages an impression has existed that the coal consumption of turbine- 
engined ships would considerably exceed that of ships driven by triple or 
quadruple expansion reciprocating engines. Critics have dwelt on the 
reticence in regard to actual rates of coal consumption practised by owners 
of turbine steamships. Naturally there are other reasons for reticence than 
those which would arise if the coal consumption were excessive; but 
pioneers in the use of turbine machinery may reasonably claim the right of 
non-publication of results of trials in the making of which they have 
incurred large expenditure and taken considerable risks, if they think that 
silence is beneficial to their business interests. Even if it were true that 
in the earliest applications of the new system economic results had not 
been obtained equal to those realised in reciprocating engines which have 
been gradually improved during half a century, that circumstance should 
not be regarded as a bar to acceptance of a type of engine that admittedly 
possesses very great advantages in other ways, but should be regarded as 
an incentive to improvements that would secure greater economy of coal. 
The evidence available, however, does not confirm the adverse view, and 
those familiar with the facts do not admit its truth. One example may be 
cited as it affects the Canadian service. In June 1907 it was authoritatively 
stated that in the Allan liner Virginian the reports which had been cir- 
culated respecting the excessive coal consumption were unfounded, that 
the vessel was making passages at speeds of 174 to 173 knots, as against the 
17 knots estimated, and the rate of coal consumption was really about 1°4 Ibs. 
per indicated horse-power which would have been required to attain this 
speed if the vessel had been fitted with reciprocating engines. This result 
compares well with the consumption in ordinary passenger steamers run- 
ning at high speeds in proportion to their dimensions, although in large 
cargo steamers and vessels of the intermediate type, working under much 
easier conditions and at very low speeds in proportion to dimensions, lower 
rates of consumption may be obtained. With these latter vessels the fair 
comparison is the combination system and not the pure turbine type which 
is adapted for high speeds. 
The crowning triumph of the marine steam turbine up to the present 
time is to be found in the great Cunard steamships Lusitania and 
Mauretania. The passages made this year by the latter ship since she was 
refitted have been marvellously regular, and the 25 knots average across the 
Atlantic, which was the maximum contemplated in the agreement between 
the Government and the Cunard Company, has been continuously exceeded. 
As one intimately concerned with the design of the Mauretania, who has 
had large experience in ship design, has made a life-long study of the laws 
of steamship performance, and had the honour of serving on the committee 
which recommended the employment of turbines in these great ships, 
I venture to assert that equal results could not possibly have been 
obtained with reciprocating engines in vessels of the same form and dimen- 
