ON THE ACTION OF AIR AND WATER UPON IRON. 283 
NO. II. 
v Jrought Tron immersed in Foul Sea Water. 
n Main Sewer. Depth of water two feet at ebb, and from eight to twelve at 
to 58° Fahr. Receives fresh water during heavy rains. Sunk at 4 
ugust, 1839, at the same hour; thus immersed 387 days. Sunk again on 
fouth of Bee = 1027-70 filtered. 
tch Cast Irons. 
7. 8. 9. 10. 11. 12. 13. 
Wate po of} Totalloss} Loss of S 2S 
Dimensions of eight of| Specimen by Weight 28 
cen, Specimen} after Sn per square | referred to} “& 25 pales § of 
in Grains. | 387 days’ inch Standard | ‘3= 3 orrosion, 
exposure, 387. oan of Surface.|_ Bar. 5 8 
moxsxl1 42895 42674 221 3:15 -297 0- Uniform P. 
moo x5xi 43636 | 43046 590 8-42 794 0: | Tubercular. 
Welsh Cast Iron. 
f 5 xl 42309 42160 149 2-13 -201 0- Uniform P. 
; j 5 x1 43689 43032 657 9°38 *885 0: Local. 
Staffordshire Iron. 
xl 42291 42237 54 0-77 073 0- Uniform. 
1 43749 43596 153 2-19 207 0: Local. 
‘ish Cast Iron. 
Bo xX A 42107 41985 122 1:74 164 0: Uniform P. 
x5xl 43155 42357 798 11-40 1:075 0- Local. 
dc or alloyed Cast Irons. 
; 5 x5x1 43193 | 43051 142 2:03 192 2:0 | Tubercular. 
5 x5x1 42232 | 42051 181 2°58 243 0- Local. 
P5x5x1 | 49215 | 42029 | 186 | 265 | -250 | 0 | Local. 
