172 ᾿ς ΒΕΡΟΒΤ--1850, 
water boilers under various forms, and all having the advantages of the valve running 
full-bore till the cistern be filled, when it closes at once, and also the surfaces not 
adhering by contact. 
In all these cases, the membrane, at least the bearing surface, is not subjected to 
the full pressure of the fluid in the pipes ; it is undera balance of forces, and the only 
force acting is the preponderating one necessary to close the valve. 
He also showed the peculiar adaptation of this valve to the water metre, an instru- 
ment of great importance, but which had hitherto failed, he believed, entirely for want 
of a sufficient delicacy and permanence in the action of the valves; also the appli- 
cation to another important case, viz. the feeding of steam-engine boilers, which he 
illustrated by drawings and a regulating apparatus, consisting of valves and float in 
a small vessel or cistern separate from the boiler, and which he had found to act with 
excellent effect. He also showed the application to annular valves, a form of great 
value, and which had been already introduced with success in pump-work, combining 
a large area of discharge with a small lift in the valve. 
The second improvement introduced by Mr. Buchanan, and involving another 
leading principle, consists in the application of the flexible substance, not merely as 
the bearing surface or lid of the valve orifice, but as a medium by which the pressure 
of the fluid, either water, steam or others flowing in the main pipes, is by a very 
simple arrangement brought to bear upon the flexible substance, and communicate 
this pressure to the lid of the valve so as to close it at once and effectually, and by 
means greatly simpler and requiring less mechanical power and arrangement than any 
hitherto in use, and by which valves and corks of the largest dimensions, and either 
of the membrane kind or of any other description, can be worked by the opening or 
shutting of a very small orifice. This principle Mr. Buchanan illustrated by 
drawings, showing the mode of applying the pressure, and by experimental models 
of cocks and valves, the effect of which appeared extraordinary and capable of exten- 
sive application, and whereby there appeared to be introduced a new principle of 
action for working hydraulic and other kinds of machinery with a degree of ease and 
facility not hitherto attained. 
Mr. Parmer Bupp made a Communication in continuation of his paper, pub- 
lished in the Transactions of the Association for 1848, “‘On the Advantageous Use 
made of the Gaseous Escape from the Blast Furnaces at Ystalyfera.”’ 
He explained how he had applied the ceconomy described in 1848 to all the fur- 
naces at the Ystalyfera works, so as to dispense with the fuel and labour before em- 
ployed to heat the blast and raise the steam for the engines. As to effect this the 
distance to which the gaseous escape had to be carried was increased, he had found 
it advantageous to drop into the furnace at the charging place a funnel or hopper of 
sheet iron, of a depth sufficient to shield entirely the mouths of the horizontal flues 
conveying off the escape. By this appliance there was about a foot of space clear 
of material, at the entrance of the flues; and the difficulty that sometimes arose in 
high winds was obviated, and the flues themselves were protected from the lodging 
of any portion of the materials thrown into the furnace. He found in practice that 
as long as there was a free ascending column through the furnace, this iron hopper 
was not injured from heat; and that the only danger of injury was during and after 
stoppages of the furnace, when the ascending column was faint and not sufficient to 
oppose the descent of the atmosphere. ; 
Mr. Budd noticed the introduction of his plan into the Scotch furnaces, and 
pointed out the great advantages that might be derived from the great abundance of 
the gaseous escape from them, from the nature of the fuel used, and stated that the 
waste heat from one furnace in Scotland would probably heat the blast and raise” 
the steam for three, leaving the top escape of two-thirds of the furnaces disposable 
for other purposes, which he pointed out. 
On the Hyperbolic Law of Elasticity of Cast Iron. 
By Homersuam Cox, B.A. Jesus College, Cambridge. 
By the formulz ordinarily used, the elasticity of a uniform iron rod subject.to direct 
extension or compression is represented as proportional, up to a certain limit, to the 
