tected by Paints or Varnishes. 
‘imensions 
of 
Specimen. in Grains.| 387 days’ 
orroded in spots, with blotches of plumbago....... Seicectten 
‘orroded in spots; no plumbago formed ............ Seeeeaeee 
kin of the iron unbroken 
kin of the iron unbroken.......... Soersianssleemeaiicee s sendete meee 
kin not broken into pits; no plumbago ............ 
kin unbroken ; no plumbago ,.........+0+ swieaniaivenae dae anaes 
kin sound, only corroded at the edges ...... penesis ise Rea ce : 
Sorroded in spots, with tubercles of oxide ........ Saeco 
orroded at edges and in pits; plumbago.........0..00. 
orroded at edges and in pits ; plumbago ..... 
eee eeecesecessesces Pee eereeeesesees veces 
6. 7. 8. 9. 10. 11. 
Weight of} Total loss} Loss of Loss of 
Weight of | Specimen by | Weight per} Weight 
Specimen after Corrosion |square inch] referred to| * 
in of Standard 
exposure. | 387 days. | Surface. Bar. 
42580 | 42143] 437 | 624 | -589 
42664 | 42490| 174 | 248 | -234 
41958 | 41691| 267 | 381 | -359 
42721 | 42466| 255 | 364 | -343 
{5x5x1 | 42293/ 41950| 343 | 4-90 | -462 
Weight of 
Water 
absorbed. 
e°¢¢°9 9 
Order of 
Protective 
Power. 
— 
ANP WOHDe NSS 
| 
ON THE ACTION OF AIR AND WATER UPON IRON. 
13. 
$$  —____ 
281 
Character 
of 
Corrosion. 
