ON THE ERECTION OF ALEXANDER III. BRIDGE IN PARIS. 
Test Requirements for Tensile Strength. 
477 
— Te iil IIl. 
Minimum ultimate— 
kg. per sq. millimetre 45 38 48 45 42 60 
( 68267 | 
Ib. per sq. inch 64000 54047 | 64000 85332 
Minimum elastic limit— 59734 | 
kg. per sq. millimetre . 24 24 24 24 22 40 
: 2 { 34130) fe 
lb. per sq. inch 34130 34130 | 31284 } 56890 
Minimum percentage 22% 28% == — 
elongation in 200 milli- 
metres | 
Minimum percentage — — }10 72 15 | 189% 
elongation in 100 milli- per cent. 
metres (150 sq. milli- 
metres specimens) | 
Results obtained for Grade III. Average for each Steel Shop. 
is shown by a letter from A to O.) 
(Each arch 
hs Arches Arches Arches Arches Arches 
A,H,L,O, | B,F,J,N, C,G,M, D,I, E.K. 
Stil 
Minimum ultimate— 
kg. per sq. millimetre 54:9 50'1 67:1 52-4 55°6 
lp. per sq. inch 78080 71252 95427 74523 | 79074 
Minimum elastic limit— 7 
kg. per sq. millimetre 28°5 27-4 36:7 28°6 34:1 
Ibs. per sq. inch 40528 38964 | 52198 40670 48501 
Minimum percentage “= _- --- -- — 
elongation in 200 
millimetres 
Minimum percentage 16:4% 19°4% 158% WiEges 170% 
elongation in 100 
millimetres (150 sq. 
millimetres specimens) 
Grade III. 
; Grade IV. { 
Test Requirements for Fragility. 
Minimum number of blows 
Height of the fall . 
Minimum number of blows 
Distance between the edge cutters 
supporting specimens ; 
Weight of the hammer . 
Height of the fall . 
160 millimetres. 
18 kilogrammes. 
Increasing from 1 metre to the 
minimum height of 1°50 by dis-- 
tances of 0:05 at each blow. 
10. 
2°75 metr 
15. 
es. 
(Specimens shaped in square bar s 
900 sq. mm. in section, 200 mm. in length.) 
The test experiments for Grade III., when compared with the similar 
tests commonly used for cast iron, are such that one could say the 
_ fragility of the steel is to the fragility of cast iron of good quality as 1: 7. 
