98 REPORT—1843. 
order. But there is another kind of wave, the wave of the first order, to which the 
sound-wave bears a remarkable analogy. This wave had been examined in another 
place (in Section A.), and the properties of this erder of wave enable us to 
solve many difficulties in the phenomena of sound. The common water-waves of 
the surface of a smooth lake had this property, that they were transmitted with 
various velocities, according to the circumstances producing the wave; but this was 
not so in the case of the sound-wave, the French Academicians having successfully 
established, that the velocities of sounds of different intensity and pitch are all trans- 
mitted in a fluid in a given condition, with precisely equal velocities ; now the chief 
peculiarity of the sound-wave is this constant of velocity, independent of the con- 
ditions of the impelling cause. Another circumstance, serving to identify the sound- 
wave with the wave of the first order, is the similar characters of the formule ex- 
pressing this velocity, whereas the formula expressing the velocity of common 
water-waves is of a form essentially different. It has further been observed, that 
there exist in the sound-wave, and in the wave of the first order, in water, the same 
polarity, the same law of diffusion, the same phenomenon of non-reflexion, at certain 
angles, and the phenomenon of lateral accumulation. From these data the author 
went on to give new explanations of the theory of whispering galleries, echoes, the 
conveyance of sound to great distances across lakes, ice, and other smooth surfaces. 
He applied the principles thus adduced to the explanation of many evils of certain 
forms of building not hitherto understood, and proceeded to develope the rules 
and methods to be adopted for the remedies of those evils. 

On the Construction of Luntley’s Shadowless Gas-burners, and the shape of 
Glass Chimneys for Lamps. By Henry Dircks. 
The object of the burner was to bring the gas issuing from the small orifices into 
direct contact with atmospheric air at the ordinary temperature. Mr. Dircks con- 
tended that the heating of the air previously to its combustion diminishes the bright- 
ness of the flame; because, while each volume of carburetted hydrogen gas requires 
ten volumes of atmospheric air for its perfect combustion, the expansion of the air 
by heat necessarily reduces the weight of oxygen contained in the same volume of 
air; and therefore, unless some means be adopted of increasing the supply of air, the 
oxygen would be deficient. Another alleged advantage of the burner arises from 
the small quantity of metal employed in its construction, and which greatly assists 
the heating of the gas preparatory to its flowing through the orifices. The pecu- 
liarity in the form of the glass chimney consists in having the upper end enlarged, 
The effect of this enlargement, Mr. Dircks said, was to open the top of the flame, to 
render its figure more cylindrical and increase its brightness. 
On the Prevention of Smoke from Engine Boilers and other Furnaces. 
By Henry Dircks. 
Mr. Dircks gave a summary description of the Argand furnace invented by Mr. C, — 
W. Williams, of which he said no less than 200 bad been put up for land engine fur- t 
naces, and that the plan was adopted on board twenty-three steamers. By a refer- 
ence to large diagrams he distinguished the difference between the mode of admitting — 
the air to these furnaces compared with any method previously practised ; he stated 
that in general inventors had endeavoured to burn as large a quantity of fuel with as 
little air as possible, but that Mr. Williams had clearly shown the importance of ad- 
mitting air to the impure gas issuing from the fuel in the furnace; and not only so, 
but likewise that that air so required must be admitted in the extremely minute form 
of small streams or jets, the mixture of the air and gas being then made with greater 
effect and dispatch. It was now, he said, important to show that this plan was at- — 
tended with considerable economy, as the best means to ensure its adoption. This, 
in the first place, depended on scientific evidence obtained by a knowledge of the 
chemistry of combustion ; in the second, it was proved by the evidence of the pyro- 
meter of Mr. H. Houldsworth of Manchester, consisting of an iron rod 30 or 40 
feet long passing through the furnace flue, and which, as it elongated by heat, and 
contracted by lowering the temperature, showed distinctly, by a lever pointing to a 

