TRANSACTIONS OF SECTION G, 853 
and using it as fuel. Possibly its advocates have claimed for it greater econonical 
advantages over coal than can be supported by the results of extended experiment. 
fiven 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 1,000 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 substantial saving on the stokehold staff, 
At present it does not appear that adequate supplies of liquid fuel are available. 
Competent 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 important 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 1,000 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 exposed 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 metallurgist 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 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 favours 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 propellers 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 wuen they must slow down and wait for better weather. But the larger and 
longer the vessel, the fewer wiil 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 
jn the past, as responsibijlities increase so will the men be found to bear them, 
