No data are available showing the relative life of wrought-iron and steel when exposed to electrolysis. However, it may be stated that the life of pipe when exposed to the pitting caused by electricity is so extremely short that the difference between the life of various materials would be too slight to be considered.

The criticism of the enduring qualities of steel, while often unfair and founded more on prejudice than personal

Table LXVIII - Loss Of Iron And Steel By Corrosion In Pounds Per Square Foot Of Surface Per Annum

Observer

Metal

Exposed to Weather

Immersed in Cold

Pure

Sea Water

Immersed in Foul Sea Water

Immersed in Fresh Water

Remarks

Pure River

Foul River

Mallet....

Wrought- iron, plain

.138

.121

.215

.013

.158

Average of 17 pieces

wroughtiron, galvanized

....

.039

.088

.005

.041

Average of 17 pieces

Thwaite's Average..

.117

.107

.214

.013

.125

Average of 7 pieces

Steel...........

Wrought-iron

.138

.121

.215

Steel..........

.137

.107

.214

Table LXIX - Relative Corrosion Of Wrought-Iron And Steel

Conditions of Exposure

Relative Corrodibility

Quality of Evidence

A In pure, cold sea water

Corrode nearly equal

Abundant and tolerably harmonious

1 Simple immersion..

Possibly little difference

Contradictory

2 Steel and bright wrought-iron in galvanic contact

3 In galvanic contact-

Scale bearing iron...

Nearly identical......

Scanty, tolerably harmonious

.Copper

Nearly identical ....

Scanty, tolerably harmonious

Steel much more corrodi-ble, perhaps 50 per cent

Very harmonious, tolerably abundant

C Exposed to weather...

Soft steel corrodes decidedly faster than

[Not so with modern steel, which is more homogeneous and resistant - F. U. S.

Harmonious, scanty

D In foul sea water......

Nearly identical.........

Harmonious, moderately abundant

E In pure, fresh water...

Nearly identical

Rather scanty

P In foul, fresh water___

Steel rather less corrodi-ble......................

Rather scanty

G In acidulated water ...

Steel decidedly the less

Scanty