686 PROCEEDINGS OF SECTION H. 
of nickel, but was greater with the 98 per cent. nickél alloy 
than with pure iron, thus— 
Puré 1f00..23.3 Ser see er OOO) 
Iron and 4 per cent. nickel ... ... 0-943 
Tron and 16 per cent. nickel... ... 0-891 
Iron and 98 per cent. nickel... ... 1-091 
Tensile Strength.—The elastic limit, yield point, and ulti- 
mate breaking strength increase gradually by the addition 
of nickel up to 10 per cent., after which a gradual decrease 
takes place up to 30 per cent. With a further increase’ of 
nickel the elastic limit and yield point decrease still more, 
while the ultimate breaking load increases, being greater 
with 60 per cent. than with 30 per cent. of-nickel. The 
elongation decreases as the percentage of nickel increases, 
till at 16 per cent. it is almost zero ;; afterwards it increases 
up to 60 per cent. nickel, and then again decreases. The 
elastic limit, yield point, and elongation of pure nickel are 
approximately 60 per cent. of those of pure iron, the 
breaking loads being about equal. 
Comopressive Strength. —The results obtained in ona 
sion are similar to those obtained in tension, but the 
resistance increases up to 16 per cent. nickel, and then 
decreases. . 
Drop Tests.—The results obtained in the drop test show 
an increase in strength up to with 16 per cent. nickel, and 
then a decrease until with 35 per cent. nickel it is the same 
as pure iron. Shearing tests gave similar results to those 
in tension. 
The following table gives the results of mechanical tests 
made by Mr. Hadfield and Professor J. O. Arnold* on prac- 
eeay pure iron and nickel :— 
Unannealed. Annealed. 
7 i Sk = =| 
di o fobs) ee B=) aea\s 
ola |ea lela 18 besiege 
Material. Pa 4 Zt |S—~|2a} 4 ZAoalecsloa 
3 2 & 2 oS Ss 2 © a 5 30'S 3 z 
5 cS Be |e siB°] Bs | 5\5 
a | @|23i8 | 8 | * male 
= Cees 2\= 
ray ae Per | Per ee oe Per | Per 
sq. in. |sq. in cent.|cent. sq. in. | sq.in cent.|cent 
Tron | C. 0°08 et Cast...) 14 20 | 16 | 34 not| o b|taijned 
Fe. 99°80',,§ | Forg’d| 14 22 47 | 76 9 18 52 | 76 
Nick- { C. 0°16 re Cast...| 11 | 16} 3} 93 not] ob | taijned, 
el. | Ni98'80,,§|Forg’d] 14 | 821 | 453,57] 7 | 313 | 54 | 523 
* Proc. Inst. C.E., vol. cxxxviii., page 8. 
