TRANSACTIONS OF THE SECTIONS. 195 
not only for the whole ship, but for her fore and after bodies separately, it being 
probable that the virtual depth of uniform disturbance, if not equal to the mean 
depth of immersion, is connected with it by some definite relation, In an appen- 
dix the author gave the results of three observations he had been able to make ; 
and, few as they had been, he thought they were suflicient to prove the existence 
of waves whose speed of advance depended on the depth to which the vessels 
disturbed the water. The connexion between these waves and the resistance re- 
mained for future investigation. 
Auxiliary Railway for Turnpike Roads and Highways passing through Towns. 
By W. Txororp. 
The author stated that he only required a single line of rails, which he proposed 
should be laid on one side of the road, out of the way of the ordinary traflic. By 
an arrangement of grooved wheels under the ,centre of the engine and carriages, so 
constructed that they will be capable of maintaining their grip upon curves of 20- 
feet radius, thereby giving the vehicles the power of turning corners with the 
greatest facility, the inventor thinks his principle peculiarly adapted to locomotion 
through new countries, and for passing through ravines, or up and down the sides 
of mountains, up any gradient not exceeding 1 in 12. He proposed to propel the 
carriages by steam-traction engines, although they might also be drawn by horses 
or other beasts of burden. The adhesion of the traction-wheels could be regulated 
to any weight, and by the application of a special apparatus the engine might be 
made to lift the traction-wheels out of a soft place. ‘The cost of the new railway 
he estimated at about £500/. per mile. 
The arrangements employed for the distribution of Water to towns and dwell- 
ings in the Middle Ages. By the Rey. Professor Wiis, PLS. 
On the Proper Form of Projectiles for Penetration under Water, 
By Josera Wurrwortn, LL.D., PRS. 
The author exhibited a photograph showing the actual effect produced on an 
iron plate in an experiment made by him with three descriptions of projectiles. 
The iron plate shown in the photograph is 50 in. long, 13 wide, 1-2 in. thick, and 
was immersed in water 39 in. deep. The gun used was the 1-pounder, from which 
all the former experiments were made previous to the first penetration of 4-in. 
armour from his 70-pounder rifled gun in October 1858, The angle of depression 
of the gun was 7° 7”, the distance which the projectile passed through the water from 
the point of entering it to the bull’s-eye is 80 inches. No. 1 projectile is Whitworth 
steel, and of the flat-headed form always advocated by the author for use at sea. The 
photograph showed that it was not deflected by passing through the water. No. 2 
shot, with hemispherical form of head, was deflected, and struck 93 in. above the 
bull’s-eye. No. 3 projectile is of white cast iron, commonly called the Palliser, or 
chilled shot, and it struck 19 in. above the bull’s-eye, its conical form of head causing 
it to rise quickly out of the water. The advantages of No.1 projectile are, first, its 
power of penetration when fired even at extreme angles against armour plates ; 
secondly, its large internal capacity as a shell; thirdly, the capability of passing 
through water and of penetrating armour below thewater line. The No. 3 projectile 
is advocated by Major Palliser, on account of its cheapness and its power of penetra- 
tion, which latter quality, however, depends upon its being fired at a near approach 
to right angles against armour plates; its adoption is also supported by the Director 
of Ordnance (at the War Office) and the President of the Ordnance Select Committee. 
The author reeretted that he had for so many years been so frequently obliged to differ 
in opinion on mechanical subjects with these gentlemen. His objections to this pro- 
jectile are, first, that when it is fired at any considerable angle against an armour 
late its form induces it to glance off, and the brittleness of the metal causes it to 
reak up; and it is to be observed that in naval actions oblique fire is the rule, and 
direct fire is the rare exception; second, that the brittleness and consequent weak- 
ness of the metal necessitate a greater thickness of the sides, and reduce its internal 
A 
