on at sl 
TRANSACTIONS OF THE SECTIONS, 101 
Mr. J. Taylor described a simple Steam-engine Indicator, which had been invented 
by Mr. A. Rous, who was formerly a working engineer in Cornwall. It consists of 
a half-second pendulum, to which a pencil is fixed and pointed against a card. The 
card is attached to the beam of the engine, and as it moves perpendicularly the pen- 
cil on the pendulum marks on it waving lines, which are wide apart when the piston 
moves quickly, and closer together as the velocity of the piston decreases. The 
distances between the lines indicate the spaces moved through by the piston in half 
a second in different parts of the stroke. 
Mr. Perry mentioned that he had received a letter from Dublin, announcing the 
complete success attending the opening of the Atmospheric Railway on the branch 
of the Kingstown and Dublin line. The length of the atmospheric rail was one mile 
and three quarters ; and the average gradient 1 in 100. After forty strokes of the 
stationary engine the vacuum gauge stood at 17 inches; after 100 strokes it was at 
2135; and it was ultimately raised to 22. The carriages were filled with passengers, 
and they ascended the line at a speed of twenty-eight miles an hour. When the 
machinery had got into proper working order, it was expected that a speed of at 
least fifty miles an hour would be attained. 

Mr. Bevan exhibited a model of a complicated kind of Paddle Wheel, intended to 
be so contrived that the floats should enter the water and come out of it perpendi- 
cularly. It was proposed to effect this by having the floats moveable and weighted, 
so as to keep them perpendicular by their own gravity. 
A communication from Mr. L. Cooke, of Parsons-town, describing a Clock Move- 
ment of his invention, and a new mode of suspending the pendulum, was read by 
Mr. Taylor. In this contrivance the pendulum is detached from all parts of the 
clock movement, and is in contact only at the suspending needle points. The pen- 
dulum is made to vibrate in half-seconds, by which means the variations owing to 
expansion and contraction are greatly diminished, and that source of error is further 
corrected by a compensating mechanical pendulum. 

Sir T. Deane explained the method adopted by his brother, Mr. A. Deane, to 
raise the Innisfaile steam-vessel, of 500 tons, which was sunk by striking against an 
anchor in the Cork river a few years ago. The ordinary methods of raising sunken 
ships having proved ineffectual, a coffer-dam. was made round the vessel in the 
middle of the river, and pumped dry by means of eight or nine chain-pumps. The 
leak was ascertained by digging under the ship, and a cow-hide was nailed over it 
to keep it water-tight. The coffer-dam was removed as quickly as possible, when 
the Jnnisfaile again floated by her own buoyancy, and the steam having been got up, 
she was taken to Passage to undergo the necessary repairs. The whole cost was 
400/., and the work was done in the course of four tides. 
Mr. J. E. Purser exhibited Life-Preservers of his invention, which are appli- 
cable in cases of fire and of shipwreck.—To show the value of this first invention, he 
descended from an upper window of the court house; and he tested the efficacy of 
the water-escape cork-jacket at Cove during the excursion on Thursday. 



Mr. G. White communicated an account of Mr, Starkey’s system of Filtration by 
sponge compressed 4, to ; of its natural bulk. 


The Rey. Mr. Scoresby described an apparatus for simplifying the illustration of 
trigonometrical operations, especially with reference to the purposes of education. 
It is called by the inventor a trigonometrical indicator. 
On a Method of Ascertaining inaccessible Distances at Sea or Land. 
By Mr. P. Leany. 
On this plan two small telescopes are fixed at the greatest distance the vessel will 
admit of, and so as to form some multiple of ten feet, This distance forms the base 
line on which the calculations are to be made. 
