SEPTEMBER 28, 1899 | 
same direction without sacrifice of strength. Necessarily there 
must be a sufficient margin to secure both strength and endur- 
ance in the motive power of steamships. Existing arrange- 
ments are the outgrowth of large experience, and new de- 
partures must be carefully scrutinised. 
The use of rotary engines, of which Mr. Parsons’ turbo-motor 
is the leading example at present, gives the prospect of further 
economies of weight. Mr. Parsons is disposed to think that he 
could about halve the weights now required for the engines, 
shafting, and propellers of an Atlantic liner while securing 
proper strength and durability. If this could be done in 
association with the use of water-tube boilers it would effect a 
revolution in the design of this class of vessel, permitting 
higher speeds to be reached without exceeding the dimensions 
of existing ships. 
It does not appear probable that, with coal as the fuel, water- 
tube boilers will surpass in economy the cylindrical boilers now 
in use ; and skilled stoking seems essential if water-tube boilers 
are to be equal to the other type in rate of coal consumption. 
The general principle holds good that as more perfect me- 
chanical appliances are introduced, so more skilled and dis- 
ciplined management is required in order that the full- benefits 
may be obtained. In all steamship performance the ‘* human 
factor” is of great importance, but its importance increases as 
the appliances become more complex. In engine-rooms the 
fact has been recognised and the want met.’ There is no 
reason why it should not be similarly dealt with in the boiler- 
rooms. : 
Liquid fuel is already substituted for coal in many steamships. 
When sufficient quantities can be obtained it has many obvious 
advantages over coal, reducing greatly manual labour in em- 
barking supplies, conveying it to the boilers and using it as fuel. 
Possibly its advocates have claimed for it greater economical 
advantages over ceal than can be supported by the results of 
extended experiment. Even if the saving in weight for equal 
evaporation is put as low as 30 per cent. of the corresponding 
weight of coal, it would amount to 1000 tons on a first-class 
Atlantic liner. This saving might be utilised in greater power 
and higher speed, or in increased load. There would be a sub- 
stantial saving on the stokehold staff. At present it does not 
appear that adequate supplies of liquid fuel are available. Com- 
petent authorities here and abroad are giving attention to this 
question, and to the development of supplies. If the want can 
be met at prices justifying the use of liquid fuel, there will 
undoubtedly be a movement in that direction. 
Stronger materials for the construction of hulls are already 
available. They are, however, as yet but little used, except for 
~special classes of vessels. Mild steel has taken the place of iron, 
and effected considerable savings of weight. Alloys of steel with 
nickel and other metals are now made which give strength and 
rigidity much superior to mild steel, in association with ample 
ductility. For destroyers and torpedo boats this stronger material 
is now largely used. It has also been adopted for certain im- 
portant parts of the structures of recent ships in the Royal Navy. 
Of course the stronger material is more costly, but its use enables 
sensible economies of weight to be made. It has been estimated, 
for example, that in an Atlantic liner of 20 knots average speed 
about 1000 tons could be saved by using nickel steel instead of 
mild steel. This saving would suffice to raise the average speed 
more than a knot, without varying the dimensions of the ship. 
Alloys of aluminium have also been used for the hulls or 
portions of the hulls of yachts, torpedo-boats, and small vessels. 
Considerable savings in weight have thus been effected. On the 
other hand, these alloys have been seriously corroded when ex- 
posed to the action of sea-water, and on that account are not 
likely to be extensively used. Other alloys will probably be 
found which will be free from this defect, and yet unite lightness 
with strength to a remarkable degree. 
Other examples. might be given of the fact that the metal- 
lurgist has by no means exhausted his resources, and that the 
shipbuilder may look to him for continued help in the struggle 
to reduce the weights of floating structures. 
It is unnecessary to amplify what has already been said as to 
possible increase in the efficiency and types of propellers. With 
limited draught, as speeds increase and greater powers have to 
be utilised, multiple propellers will probably come into use. Mr. 
Parsons has shown how such problems may be dealt with ; and 
other investigators have done valuable work in the same 
direction. 
In view of what has happened and is still happening, it is 
NO. 1561, VOL. 60] 
NATURE 
535 
practically certain that the dimensions of steamships have not 
yet attained a maximum. 
Thanks to mechanical appliances, the largest ships built or to 
be built can be readily steered and worked. In this particular 
difficulties have diminished in recent years, notwithstanding the 
great growth in dimensions. 
Increase in length and weight favour the better maintenance 
of speed at sea. The tendency, therefore, will be to even greater 
regularity of service than at present. Quicker passages will to 
some extent diminish risks, and the chance of breakdown will be 
lessened if multiple propeilers are used. Even now, with twin 
screws, the risk of total breakdown is extremely small. 
Whatever may be the size and power of steamships, there must 
come times at sea when they must slow down and wait*for better 
weather. But the larger and longer the vessel, the fewer will 
be the occasions when this precaution need be exercised. 
It must never be forgotten that as ships grow in size, speed, 
and cost, so the responsibilities of those in charge increase! 
The captain of a modern steamship needs remarkable qualities 
to perform his multifarious duties efficiently. The chief engineer 
must have great powers of organisation, as well as good technical 
knowledge, to control and utilise most advantageously the men 
and machinery in his charge. Apart from the ceaseless care, 
watchfulness and skill of officers and men, the finest ships and 
most perfect machinery are of little avail. The ‘‘ human factor ? 
is often forgotten, but is all-important. _ Let us hope that in the 
future, as in the past, as responsibilities increase so will the men 
be found to bear them. 
NOTES. 
A STATUE, erected in memory of the late M. F. Tisserand, 
will be unveiled at Nuits-Saint-Georges on October 15. 
Major RONALD Ross has sent Mr. A. L. Jones a letter from 
Sierra Leone on his investigations into the cause of malaria. 
In the course of the communication he says:—We have now 
practically finished our work here. We have found—(a) that 
local species of Anopheles (mosquitoes) carry malaria ; (6) that 
these species breed in a few stagnant puddles. For many 
scientific reasons we have come to the conclusion that the truly 
malarial fever is caused here solely by the mosquito—probably 
entirely by the Anopheles species. We estimate then that most 
of the malarial fever here can be got rid of at almost no cost 
except of a little energy on the part of the local authorities. 
A SUCCESSION of earthquake shocks occurred on Monday 
night, September 25, in the district of Darjeeling, involving 
great loss of life and damage to property. No details as to the 
exact times of the shocks have been received. The earthquake 
was accompanied by a remarkable rainfall, and was followed by 
extensive landslips. It is reported that in twenty-four hours 
over 20 inches of rain fell, and in all 28 inches fell in thirty- 
eight hours. 
THE associate editorship of the American Journal of Science, 
vacant by the death of Prof. Marsh, has been taken up by Prof. 
L. V. Pirsson, of Yale College. 
IN a report just issued on metalliferous mines in the North 
Wales district, Dr. C. Le Neve Foster refers to the fact that 
several foreign companies have lately purchased mines in that 
district with the object of reworking them. He remarks :— 
“ Though I welcome the advent into Wales of the famous 
Vieille Montagne Company, for I have hopes that its methods 
of mining and dressing will form useful object-lessons to us, Tam 
not blind to the slur which is cast upon us as a mining nation. 
If such a capable body of commercial men as the directors of the 
Vieille Montagne Company propose to resuscitate some of our 
abandoned mines, it may be taken for granted that they consider 
the enterprise as likely to be profitable. Is our mining talent so 
far behind the times that foreigners can make a profit out of 
mines which we have abandoned as worthless? If so, the 
