390 SEVENTH REPORT—1837. 
placed on the centre, and supported on beams or bearers 3 feet 
asunder. The results are below : 
Mean breaking weight of the Cold Blast bars 947 lbs. 
Mean ditto ditto Hot Blast bars 787 ,, 
Difference in favour of Cold Blast 160 
being as 94 to 78 in the ratio of 1000 to 831, or nearly the 
same in favour of the cold blast as exhibited in the preceding 
tables. 
It appears somewhat remarkable, that the same, or nearly the 
same, results should be obtained in my experiments of 1836, on 
the Elsicar and Milton irons, as were elicited in the experiments 
at the Low Moor in 1830. In both instances there is an obvi- 
ous defect in the strengths of the iron made by the hot blast ; 
and, judging from the difference in the deflections between the 
Elsicar and the Milton, I should consider the hot blast more 
tender than the Elsicar, and less worthy of trust than it when 
submitted to forcible strain under vibratory action; the power 
to sustain impact being in favour of the former as 1000 to 875. 
Before closing these observations, I would venture to mention 
the striking anomaly that exists between the Yorkshire ores and 
those of other districts when operated upon by the hot blast. 
From the experiments generally, such a marked difference does 
not exist in the strength of other irons as are herein portrayed 
in those of Yorkshire. Some peculiar and probably unknown 
affinity in the minerals may be brought into action by the heated 
air, otherwise, 1 confess, I cannot perceive any just reason for 
such a change. The mere heating of atmospheric air to 600° or 
700° before it enters the furnace, should not, in my opinion, 
differ so considerably from the same air heated in the furnace. 
I hope the results of these experiments will induce Dr. Faraday, 
Dr. Thompson, or some other eminent chemist, to inquire fur- 
ther into this subject, and, by correct analysis, to ascertain the 
cause of differences which at the present moment appear any- 
thing but satisfactory. 
ae ae ee 
