148 . NAT ORE 
in the recent regulations for junior technical schools, 
states that these schools are not intended to furnish a 
preparation for higher ‘‘full-time’’ technical work, 
this being one of the functions of the secondary school. 
This would make the junior technical schools a “‘ dead 
end”’ so far as further day technical work is concerned. 
In science and mathematics, the fundamental subjects 
in technical work, the boy in the junior technical 
school is ahead of the secondary-school boy. The 
junior technical school should be another avenue, 
alternative to the secondary school, by means of which 
the bright boy could pass from the elementary school 
to the technical college. 
in the case of the boy who develops somewhat late 
or whose mental activities only become aroused by 
contact with things rather than with books. 
J. Wizson. 
THE INSTITUTION OF NAVAL 
ARCHITECTS. 
HE spring meeting of the Institution of Naval 
Architects opened on April 1 at the rooms of 
the Royal Society of Arts. The institution’s gold 
medal was awarded to Mr. G. S. Baker, for his paper 
on methodical experiments on mercantile ship forms. 
Premiums were awarded to Messrs. A. Cannon and 
L. Woollard for papers dealing respectively with the 
effect of loose water on the rolling of a ship, and the 
effect of water chambers on the rolling of ships. In 
all fourteen papers were read and discussed during the 
three days over which the meeting extended. 
In a paper dealing with some questions relating to 
battleship design, Mr. T. G. Owens states that the 
present tendency in warship construction and design, 
as exemplified in the later ships of all the principal 
maritime powers, is towards very large displacements, 
with the arrangement of all the guns of the primary 
armament on the centre line, and with the guns of 
the secondary armament placed in an armoured citadel 
on, or immediately below, the deck carrying the 
primary guns. In respect to the above-water armoured 
protection, there is the usual thick armoured belt, 
extending, say from 4 to 6 ft. below the water-line, 
to the height of the main deck, and carried along the 
length of the vessel for such distance as to protect 
the machinery and boiler compartments and the maga- 
zines. The ends of the ship and the citadel have 
armour of reduced thickness. In all modern battle- 
‘ships there are horizontal protective decks. Protection 
against attack from bombs, etc., dropped from air- 
craft is not yet in the region of practical politics. 
‘When the time arrives to arrange measures to meet 
such attack, they will probably take form in the 
method advocated by Sir Trevor Dawson, i.e. to in- 
crease the thickness, and give a greater curvature, or 
whale-back formation, to the armoured deck. 
Mr. W. J. Luke contributed a paper on experiments 
upon wake and thrust deduction, supplementary to 
another paper which he presented to the institution 
in 1910. The present paper has particular reference 
to experiments with contrary-turning screws on a 
common axis, with tandem screws, and also of ex- 
periments with quadruple screws. It appears from 
the experiments that the first-mentioned type of screw 
has not a little to recommend it, and were the 
engineering difficulties connected with its application 
to marine propulsion overcome, it would be well 
worthy of consideration. Tandem screws have nothing 
to recommend them. 
Mr. J. T. Milton read a paper on the present posi- 
tion of Diesel engines for marine purposes, and Prof. 
W. E. Dalby described some results of trials made on 
a small Diesel engine in which accurate indicator 
NO. 2319, VOL. 93] 
This is especially important - 
[APRIL 9, 1914 
diagrams were obtained by means of a-new form of 
optical indicator. 
Mr. G. S. Baker gave an account of a number of 
model experiments made to determine the effect of 
shape of area curve on the resistance at any reason- 
able speed. This paper gives also a brief account of 
the work of the year at the William Froude tank. A 
large proportion of time has been spent-on test work 
for various shipbuilding firms. The resistance of 
at least five large vesseis has been reduced more thar 
10 per cent. by modifications to the form made at the 
tank, and several others have been improved in a less 
degree. The importance and value of these results 
can be seen from the fact that the saving in cost 
of coal per annum fora single one of the above five ships 
would be more than sufficient to support the experi- 
mental tank for the same period. The investigation 
of the resistance and tipping moments experienced by 
aero-hydroplane floats has been continued. Consider- 
able improvement has been effected in the power re- 
quired for their propulsion, the tipping moments due 
to the water forces are now known, and a float which 
is stable in character and of a low water resistance 
has been evolved. Ship models have been tested with 
four different kinds of surface, the paraffin wax being 
(a) bare, (b) freshly coated with shellac varnish, (c) 
the same, with blacklead rubbed into a coating of 
shellac when the latter was ‘‘ tacky,’’ and then allowed 
to harden, (d) coated with red lead paint. The spots 
from the four surfaces were indistinguishable, and 
show that, provided the surface is smooth and free 
from grit, the same result will be obtained. 
Mr. H. Gray gave the results of experience with 
superheated steam, with special reference to economy 
and cost of upkeep, based on more than three years’ 
working in engines of both triple- and quadruple- 
expansion types in the mercantile marine engaged in 
regular trade, voyage after voyage, to Australia vid 
the Cape of Good Hope. The system adopted was the 
Schmidt. None of the steamers have been delayed 
either in port or on the voyage by reason of super- 
heater defects, notwithstanding the fact that the runs 
are long—that of the Port Augusta being forty-five 
days without a call at any port. Lubrication of the 
cylinders and valve faces is of the utmost importance 
with superheated steam, and it is absolutely necessary 
to have a trustworthy system of filtration for the 
feed-water, so as to ensure the abstraction of the oil 
and to safeguard the boilers from the possibility of 
any traces of oil being introduced. The author states 
that the economy of triple-expansion engines of 
2000 i.h.p. after being altered to use superheated 
steam, has been increased about 12 per cent., and of 
quadruple-expansion engines, about 17-8 per cent. 
Mr. C. E. Stromeyer contributed a paper on the 
elasticity and endurance of steam pipes, and a note on 
the Foster strain meter, and some data obtained there- 
with were presented by Mr. W. R. Gerald Whiting. 
Dr. K. Suyehiro, professor of naval architecture at 
Tokio Imperial University, described a new torsion- 
meter which he has devised. This instrument has 
some interesting features. The angle of twist of the 
shaft is measured by the relative rotation of two arms, 
one clamped to the shaft, and the other carried by a 
long tube clamped to the shaft at the end remote from 
the other arm. The first-mentioned arm carries a 
scale having half-millimetres along one edge and a 
reading scale along the other. The scale faces the 
shaft, and mounted on the same arm is a plane mirror, 
situated half-way between the shaft axis and the 
scale. Hence a virtual image of the scale will be 
seen every revolution, coinciding with the shaft 
axis, and therefore at rest. On the other arm is a 
concave mirror which forms an image of the reading 
1 edge of the scale, also on the shaft axis, and side by 
