1050 REPORT OF THE HARVARD AFRICAN EXPEDITION 
they must be loaded into holders or magazines in a dark room or in a chang- 
ing bag. But this is not a serious handicap if any extensive work is to be done. 
I solved the problem by having two magazines holding twelve films each. In 
addition I had twelve double cut film holders. This gave me four dozen ex- 
posures without reloading and although I was occasionally forced to use a 
daylight loading bag I suffered little inconvenience. Incidentally, with a little 
practice one can work very quickly with the bag. The only difficulty is from 
the hands sweating. By practice one can get through unloading, boxing the 
films and reloading before this has become too marked. 
Film packs are lighter and more easily changed. Their chief disadvantage 
in the tropics is the fact that they may all stick together so that when the first 
tab is pulled, the entire twelve are brought back together. On account of 
this danger I took no film packs. With care, however, I think this could be 
avoided if the packs are kept well sealed up to the time of use. 
Unless one is using a roll film camera I would advise against roll films if 
one expects to develop in the field. They are awkward to handle and are easily 
scratched. On the other hand, with six picture rolls and each one in a sealed 
tin, they can be very convenient in the rainy season for they are then subjected 
to the minimum moisture, can be quickly returned to their tins and stored 
away. I took a limited amount with me for just such conditions. Actually 
I found them acceptable at the end of the trip where I was no longer devel- 
oping my pictures and did not wish the bother of unloading cut film magazines. 
With regard to the keeping of this film, I found that the best method 
was to actually solder it into tin containers making sure that the cap extends 
well down over the top. Then after opening and using the film it can be put 
back in the tin, the cap put on and the opening taped with adhesive. ‘This 
protects against further moisture until developing. I never put more than 
three dozen individual pictures into one tin for fear of having them open too 
long. I also had my roll film and cinema film packed in this way but with 
these, each roll was in an individual taped tin for further protection so that 
none were open to the atmosphere except while in the camera — and were im- 
mediately returned to their container when exposed. The movie film was in 
one-hundred-foot lots, five hundred feet to the large tin. While mentioning 
movie film, I might state that eight tins of five hundred feet each in their wooden 
box weighed about sixty pounds which is considered a one-man load. 
The use of filters will have to be adjusted to the film. Their advantages 
are the same as in more temperate climates. 
Development was to me a prospective hazard but quite simple in retro- 
spect. I tested out several varieties of developing formulae and eventually 
decided on the following, recommended by Mr. Herbert Lang of the Museum 
of Natural History in New York. 
POSTE AMICON 2. 0.0 s einen «awe i 
Sodium Sulfite (anhydrous)...... 10 
Potassium Bromide............. if 
