78 
on to detail the following experiments, which he had, by 
the kindness of the several parties named, caused to be 
made during the severe frosts which have recently prevailed; 
and which have in all cases been carried out with the 
greatest care and exactness. 
Experiments on the transverse strain of cast iron bars 
were made at the works of Messrs. P. ft. Jackson and Co., 
of Salford, and were repeated thrice, with the following 
results : — 
In Mr. Fairbairn’s experiments only one sort of pig iron 
was employed. It is now "well known that a much sounder, 
and more regular casting, can be obtained by a judicious 
admixture of several suitable kinds of pig iron; a very pro- 
bable source of error would thus occur in Mr. Fairbairn’s 
experiments, and this will probably point to the unsatisfac- 
tory results he obtained. 
The bars employed in the present experiments were made 
from a mixture of four pig irons of the highest class, added to 
some good scrap iron ; they were all poured from the same 
ladle, and were moulded from the same model, and they were 
remarkably regular in size and quality, so that the results 
may be fairly relied on. The castings w r ere all made on F riday, 
the 30th of December last, and the bars were tested ou the 
following Tuesday, January 3, 1871. The machine used 
was a powerful lever or steel yard, the bars having a three 
feet bearing, and the results were taken with all possible 
care, and are detailed in the following table. 
Experiments upon the transverse strain of cast iron at 
low temperature, made at the works of Messrs. P. It. Jack- 
son and Co., Salford, January 3, 1871, by W. JBrockbank, 
F.G.S. 
The mixture of metals was Cleator Hematite, Ponty Pool 
cold blast, Blaenavon cold blast, and Glengarnock hot blast 
pig iron, with some good scrap iron. All the bars cast from 
one ladle. 
