150 Miscellaneous Intelligence. 
The above is freely translated from a paper inserted by 
M. Brard, in the Bib. Univ. xxiv. 224. 
3. On the Strength of Cast Iron and other Metals.—It was our 
intention to have noticed a new edition of Mr. Tredgold’s valuable 
essay on the above subject, in a former part of our Journal, but 
this has been prevented by the pressure of other matter. We 
must, therefore, rest satisfied with laying before our readers the 
contents of the eleven sections into which the work is divided, 
reserving to a future occasion a more explicit account of its 
contents. 
The First Section consists of introductory remarks on the use 
and the qualites of cast iron; and of cautions to be observed in 
employing it. This section is followed by three extensive tables, 
which will often save the practical man a considerable share of 
trouble in calculation. 
The Second Section explains the arrangement and use of the 
tables, which precede it ; and in this edition, the number of popu- 
lar examples is much increased. 
It is a common and a well understood fact, that an uniform 
beam is not equally strained in every part, and therefore may be 
reduced in size, so as to lessen both the strain and the expense of 
material. 
The Third Section points out the value of cast iron, in this par- 
ticular, and the forms to be adopted for different cases, 
The Fourth Section contains a popular explanation of the 
strongest forms for the sections of beams; the construction of 
open beams ; and the best forms for shafts. A due consideration 
of these two sections will enable the young mechanic to guard 
against some common errors in attempting to apply these things to 
practice. They are much augmented, and a new principle of con- 
structing bridges is explained in the fourth section, _ 
The Fifth Section is wholly devoted to experiments on cast 
iron; it will be found to contain, in addition to the author’s expe- 
riments, almost all of the experiments that have been described 
by preceding writers. 
To this section a great many new experiments have also been 
added, to show the relative strength of iron of different qualities ; 
and also seven new experiments on torsion, made by Messrs. 
Bramah. The section concludes with the result of the author’s 
observations on the relation between the appearance of the 
fracture and the strength of cast iron as determined by expe- 
riment. 
The Stath Section contains experiments on malleable iron and 
other metals, and is entirely new. The effect of hammering and 
the decrease of force by heat, are experimentally examined ; and 
