ON THE ACTION OF AIR AND WATER UPON IRON. 289 
andard bar of Wrought Iron. 
ve 8. a 10. 11. 12. 13. 
Weight of| Total loss Lossof | S 
Loss of au 
Weight of | Specimen by Weight | £22 
Specimen after a Weisbtner setetrel to SEs Character of 
in Grains.| 117 dagnt square inch] Standard | 3 2 ‘orrosion. 
exposure. | 117 nae. of Surface. |." Bar, 5 8 
a | | | 
24464 | 24274 190 4-318 1:35 0: | Unif. striated. 
a removed by planing. 
6x5x 75 | 34024 | 30750 | 274 | 4:2) | 1:31 | 0: 
| Uniform. | 
pr Beected by Paints or Varnishes. 
PS 
| “5x5x1 | 42618 | 42594 24 | O84 | -106.).0 | 4. ,» 
5x5x1 | 42673 | 42644 SCORN Ss TARE Ge: «|. gamers 
5x5x1 | 42457 | 42399 58 | 083 | 259 | o | . 
he x5x1 | 42075 | 42007} 68 | 097 | 303 | o | , , 
5x5x1_ | 42094 | 42004 90 | 1:28 | 368 | o | , 4 
jox No. 3. Class No. 8. 
' - 
Order of 
_ Condition of surface of Specimen after 117 days’ exposure. Protective 
; Power. 
, a 
Uniform rusting. Surface hard ..........++ chose depen cadaorc 1 
ted in spots. Hard. No plumbago aeeee 4 
nsound. Minute cavities.......... Moasecpiesveweveer seas eee 2 
sound. Hard rust uniformly ........sccecsesccsceceenees 3 
ound. Hard uniform rust, ........seceeseeee ascccecco ne 5 
Hsound. Uniform rust .......seseecseessecseseees sciweactees 6 
still fresh in parts. Rusted in pits ......+s0see00es cece 8 
in spots. Plumbago in spots ......sssessesesseseeeeees 7 
nbago in various spots 9 
edin places. Hard rust uniformly ooeees 10 
| 1840, U 
