397 



2 



Close-up photographs were taken of all interesting features including 

 biological growths. Close-up photographs were located with respect to the 

 container by taking photo pairs. First, an overall picture was taken of the 

 container with a cut-out cardboard frame held over the feature of interest. 

 The camera was then repositioned and a close-up photograph was taken of the 

 area within the frame. The photographs presented in this report were printed 

 from color plates made from selected original color slides. 



The pH of the corrosion products and the mud layer, where it was still 

 clinging to the drum, was spot checked at several locations while the drum 

 surface was still wet. Readings were taken with pH indicator papers and 

 recorded for each location. 



Samples of the corrosion product were taken both from the outer layers 

 (reddish orange) and from the layer immediately adjacent to the bare metal 

 surface (greenish black) at a location just above the mudline on the 

 cylindrical surface near the metal end and were examined for bacterial 

 activity. The examination was done both immediately on board the ship as well 

 as subsequently ashore in the laboratory. A Unitron BPH phase contrast 

 microscope was used for all observations. The samples observed on board were 

 examined directly at 600X by spreading the moist sample on a glass slide. 

 These observations were very difficult due to ship roll and vibration. The 

 samples to be observed in the laboratory were diluted with seawater that had 

 been passed through a 0.22 urn membrane filter (Millipore) and encapsulated in 

 glass vials to prevent them from drying. In the laboratory, these samples 

 were spread between a glass slide and coverslip and examined in phase contrast 



