556 INQUIRY INTO THE STRENGTH 
At the conclusion of my former paper in this 
volume, I gave a general summary of results 
comprising the strength and other properties of - 
forty-nine sorts of British irons. They were 
ranked according to their relative strengths, 
taken from the mean breaking weights of bars one 
inch square, placed upon supports 4ft. 6in. asunder. 
The strongest being marked No. 1, and the others 
according to their respective ranks in the scale.* 
On this occasion it will be necessary to follow 
the same rule as that formerly used, and to collect 
the results from the experiments on the anthracite 
iron, into a similar form. 
I have found these summaries of considerable 
value in judging of the different kinds of iron ; and 
if they were generally used, and taken as a guide 
by the architect and engineer, I have every reason 
to hope that improper mixtures, as well as the use 
of improper material in castings, would be pre- 
vented. 
* The irons experimented upon were mostly obtained from 
the makers or their agents; and if any iron should be misre- 
presented, or not have had full justice done to it, it will 
afford me great pleasure to rectify the defect or omission. 
