UNIFICATION OF METHODS IN TESTING MATERIALS, LI. 
Weight of rail in pounds per yard 80 Height of drop 20 feet 
85 20 
” ” ” 90 ” 7 20 ,, 
” Beer ay 95 % ” 20 4 
” ” ” 100 Te ” 20 ; 
Ninty per cent of such tests should stand without fracture, and 
when fracture occurred the rails must show 5% elongation on the 
most strained inch on the tension side. The high percentages of 
carbon and manganese used would be considered too great by 
English engineers, but the results obtained by this specification 
so far have been very satisfactory. In the case of railway tyres 
and axles, also propeller shafts, armour plates, guns, etc., the 
object aimed at was to producea material of the greatest strength 
and elasticity consistent with sufficient ductility to enable it to 
resist the shocks and general rough usage to which it was subjected. 
Chemical composition must be carefully attended to by the manu- 
facturer in such cases and subsequent hem Bots it did not 
appear wise for the engi 
which were necessarily better eitideriitiogd at the works, more 
especially as the quality can be completely ascertained by suitable 
physical tests. Moreover, the mechanical processes to which the 
ingot is subjected differed in the various steel works, to such an 
extent, that if the chemical composition were the same in each 
case, the resulting products would be by no means uniform. The 
subject of physical tests of steel and chemical composition was 
now attracting considerable attention, and the effect of carbon, 
Manganese, silicon, phosphorus, and sulphur, on the strength, 
elasticity, and ductility of the metal was fairly well understood. 
iL 
to fix 
Mr. Cunningham has given some results of Mr. Campbell’s 
investigations as to the strengthening effect of the various com- 
ponents of steel,’ which are of considerable interest in regard to 
the question of chemical and physical tests. He says that, the 
strength of pure iron, as far as it can be determined from the 
1 Proc. American Society of Civil Engineers, Vol. xx111., No. 5. 
