7 As] Engineering. 541 
ENGINEERING—CIVIL AND MECHANICAL. 
The past season has, as is usual at that time of the year, been devoted to 
the meetings of Associations, at which engineering science has been largely 
represented. Section G of the British Association is devoted to mechanical 
science: a considerable amount of what is interesting to mechanical engineers 
finds its place in papers read at the autumnal meeting of the Iron and Steel 
Institute, as well as at the meetings of the Mechanical Engineers. 
British Association.—Professor James Thompson, President of Seéion G, 
drew attention in his Address to the important question of railway accidents 
and the means of their prevention, and he traced the gradual development of 
progress in mechanical improvements as applied principally to points and 
signals. As this will form the subject of a separate article in a future number 
of the « Quarterly Journal of Science,” we shall not dwell further upon it on 
the present occasion. From thence the Professor referred to the subject of 
steam navigation, the rapid progress of which he attributed mainly to the 
introduétion jointly of the screw propeller, the compound engine, steam 
jacketting of the cylinders, superheated steam, and the surface condenser. 
The invention of the screw propeller has enabled steam to be used as an 
auxiliary motive-power in ocean steamers, for which paddles were inapplicable, 
whilst the other improvements have tended to an economy in fuel—an essential 
object in long voyages,—and by the use of which the consumption of coal is often 
now found to be reduced to about 2 lbs. per indicated horse-power per hour, 
from having been 4 lbs. or 5 lbs. in good engines in times previous to about 
twenty years ago. Deep sea sounding was next reviewed, and Sir William 
Thomson’s new machine referred to, with which soundings have been made in 
the Bay of Biscay, and a specimen of the bottom brought up from a depth of 
2700 fathoms, or a little more than three miles. One important feature in 
this machine consists in a fri€tion brake arrangement, by means of which the 
arrival of the sinker at the bottom is indicated very exactly on board the ship. 
The illumination of lighthouses was next considered, the improvements in 
which were briefly explained. The practicability of employing gas has been 
one great movement in advance, and Sir William Thomson has recently 
succeeded in perfecting a self-signalling apparatus, by which different light- 
houses may readily be recognised and distinguished from one another, and 
which is about to be adopted by the Belfast Harbour Commissioners. The 
Dublin harbour works carried out by Mr. Bindon Stoney, with concrete 
masonry blocks of 350 tons weight each, to which Mr. Thomson referred, has 
already been explained in Engineering Chronicles ona former occasion. From 
these subjects the Professor next branched off into the regions of sanitary 
engineering, wherein he dwelt principally upon the defective drainage and 
ventilation of our buildings, and the smoke nuisance of our towns. With 
reference to the latter subject he pointed out the economy that resulted from 
the use of well-known mechanical contrivances for the more effectual com- 
bustion of coal, and he instanced a case where one method is applied to about 
thirty ordinary 40 horse-power boilers, in which upwards of roo tons of coal 
are burned daily, and from the chimneys of which not more smoke is emitted 
than from many a kitchen fire. By the adoption of this method the bed of 
coal, which is gradually supplied in front, is caused to travel along the bars 
towards the inner end of the furnace, and the combustion proceeds in a very 
uniform manner in conditions highly favourable to economy of fuel, and 
without the emission of almost any visible smoke. 
We shall notice two papers that were read before this Section, viz., “On 
the Upper Bann,” by John Smyth, and ‘‘ On the Eclipsing Apparatus at Holy- 
wood Lighthouse,” by Mr. W. Bottomley. 
The former paper gave an account of recent works undertaken for improving 
the water supply of the river Bann for the mills which are established on its 
banks ; for this purpose, the Bann Reservoir Company was formed in 1835, 
and by its means the Loughislandreavy reservoir was finished in 1839, and 
the Corbet reservoir in 1847. Loughislandreavy reservoir is situated in a 
narrow valley in the flank of the Mourne Mountains, and receives three-fourths 
VOL. Iv. (N.S.) 30 
