TRANSACTIONS OF SECTION G. 623 
a roof tank of 5,000 gallons capacity by a centrifugal pump of 200 gallons 
capacity per minute, and it is returned to the laboratory by a falling main for use 
anew. 
The hydraulic machines already installed comprise an inward-flow pressure 
turbine, an outward-flow Girard turbine, a Worthington pump, a three-cylinder 
hydraulic engine, and a considerable amount of other apparatus for experimental 
work. 
The heat engines are all of moderate size, and are in most cases of special 
design for experimental work. 
A gas engine of 12 horse-power is fitted for work with either town gas or 
suction gas from a Dowson producer. A refrigerating plant is arranged to work 
with either carbonic acid er ammonia by using interchangeable cylinders, An oil 
engine, hot-air engine, steam engines, and a compound air-compressor are also 
installed, while space has been left for future developments. 
The equipment also includes a 10-tcn Buckton testing-machine and a varied 
collection of other apparatus for testing materials. 
The drawing-office has accommodation for a hundred students, and is divided 
by a glazed partition for convenience in teaching. 
The workshops have been entirely remodelled, and nearly all the old machine- 
tools have been replaced by new ones. 
A new lecture-theatre seats a hundred students, and is fitted with the neces 
sary appliances for experimental and lantern demonstrations. 
TUESDAY, AUGUST 6. 
The following Papers were read :— 
1. Ferro-concrete and Examples of Construction. 
By J.8. HE. pe Vusian, I Inst.C.#., MInst.M.£. 
The author referred briefly to the various kinds of materials that have been 
used for constructing buildings from early days, and showed that ferro-concrete 
was the most rational method, as in the Hennebique system the disposition of 
concrete and steel allowed of the maximum inherent strength of the two materials 
being made the utmost use of—that is to say, that the steel takes up all the strains 
due to tension, while the concrete bears those due to compression. In this manner 
one square inch of steel (say in the tension area of a beam) will interest 30 square 
inches of concrete on the compression side; and when one thinks of the different 
cost of concrete and steel, the economy is at once apparent. Not only is this 
method economical, it is also extremely durable and fireproof. The importance of 
careful selection, of mixing, and treatment of the concrete was shown, and the 
specifications for this, as well as for the steel, set forth. 
The author insisted on the test of reinforced concrete buildings, shortly after 
construction, with a load of 50 per cent. in excess of the calculated load. 
The behaviour of Hennebique ferro-concrete under stresses shows that this is 
really a new material, as its behaviour is so different from that of the concrete and 
steel separately. 
Perhaps one of the most marvellous uses of ferro-concrete is in the manufacture 
and use of piles. It seems a strange fact that a loose frame of steel bars and a 
concrete setting can be made which one can drive into the ground better than any 
timber piles, 
An important point which is often raised is the protection afforded to the steel 
by the concrete, and this the author mentioned, giving as an instance the head of 
a pile which had been cut off and left on the foreshore, where it was uncovered and 
covered by the tide for over nine years, and in which the steel showed as good as 
new a quarter of an inch under the skin of the concrete. This pile-head was brought 
up and broken in the presence of several eminent engineers the year before last, 
' Published in ewtenso in the Contract Jowrnal, August 21. 
