
TRANSACTIONS OF THE SECTIONS. 125 
An Account of the Drainage of the Middle Level of the Bedford Level ; with 
Observations on Arterial Drainage. By James Cooper. 

On the Mechanical Properties of Metals, as derived from repeated Meltings, 
exhibiting the maximum Point of Strength, and the Causes of Deterioration. 
By Witu1aM Farireairn, F.RS. 
After some preliminary observations, Mr. Fairbairn stated that having been 
requested by the British Association, at their last meeting, to undertake an inquiry 
into the mechanical properties of cast iron, as deduced from repeated meltings, and 
feeling desirous of ascertaining to what extent it was improved or deteriorated, 
arrangements were made for conducting a series of experiments, calculated satisfac- 
torily to determine this question, and to supply such data and such information as 
will enable the engineer and iron-founder to ascevtain with greater certainty how far 
those remeltings can be carried with safety; or till such time as the maximum of 
strength is obtained, and such other properties as appear to affect the uses of this 
valuable and important material. Mr. Fairbairn further stated, in connection with 
this subject, that it was his intention to investigate another important process, which, 
to a considerable extent, affects the stability of some of our most important iron con- 
structions, viz. the rate of cooling as it affects the adhesive properties of the material, 
and the more complete and effective process of crystallization. On these points it is 
well known that a rapid rate of cooling is invariably attended with risk; that an im- 
perfect crystalline structure is obtained, and that irregular and unequal contractions 
are not only present, but they are frequently the forerunners of disruption, as well as 
exceedingly deceptive as regards appearances, or the dangerous consequences which 
invariably follow in cases of rapid cooling and unequal contraction. 
On the Tensile Strength of Unwrought Iron Plates at various Temperatures. 
By Wii11aM Farreairn, F.RS. 
_ Mr. Fairbairn said, the experiments were not sufficiently advanced to enable him 
to lay before the Section any detailed account of them, in consequence of the appa- 
ratus for conducting those experiments having, for the last six months, been pre- 
occupied for the Royal Society to'determine the temperature of fusion or the laws of 
the solidification of bodies under great pressure. Under these circumstances, it was 
next to impossible to make much progress with the experiments on the effects of tem- 
perature, &c. on wrought iron plates. Up to the present time, they must therefore 
be considered preliminary; but, judging results obtained on a former occasion from 
experiments on bars of iron subjected to a transverse strain at varied degrees of tem- 
perature, it is more than probable that some new and interesting facts may be deve- 
loped by those now in progress. 
New Tubular Boiler. By Witw1aM Fairpairn, F.R.S. 
This subject was illustrated by tables and diagrams. The new boiler consists of 
two furnaces, the same as the double-flue boiler, but with this difference, that the 
cylindrical flues which contain the grate bars are united at a distance of eight feet 
from the front of the boiler into a circular flue which forms the mixing chamber, and 
which terminates in a dise plate, which contains a series of three-inch tubes, eight 
feet long, and similar to the locomotive boiler. These tubes in a boiler seven feet 
diameter are 104 to 110 in number, and from the thinness of the metal become the 
absorbents of the surplus heat escaping from the mixing chamber and the furnace. 
On this principle of rapid conduction, the whole of the heat, excepting only what is 
necessary to maintain the draught, is transmitted into the boiler, and hence follows 
the ceconomy of entirely dispensing with brickwork and flues—an important deside~ 
ratum in these constructions. 

Remarks on the Minie Rifle. By WitiiAM Farrzairy, F.R.S. 
Mr. Fairbairn observed that, until of late years, all the gun barrels for the army, 
and other descriptions, had to be welded upon mandrils, some of them formed by a 
