82 SMITH. 



PHOTOGRAPHY. 



In the experience of the writer and his associates in the Bureau 

 of Science the following rather definite conclusions and suggestions 

 may be made for this region: 



1. A 4x5 Graft ex camera. 



2. Use Seed's Non-halation plates. For contrast effects Wratten 

 and Wainwright's panchromatic plates are recommended. Plates 

 will keep without becoming moldy about a week, except in 

 the dry season when they can be kept longer. 



3. A portable developing outfit should be taken on long expeditons 

 into the interior. Water tight containers should be provided 

 for plates, films and chemicals. 



4. Practically the same time of exposure is required for pictures 

 as in higher latitudes. If anything a somewhat longer exposure 

 necessary. This is contrary to the general belief, but it is- 

 based upon both theoretical data and practical experience. 

 Freer and Gibbs have shown that tropical sunlight is not 

 materially different from any other sunlight. 



5. Don't bring cameras using other than standard (for U.S.) size 

 plates or films unless you are supplied with sufficient of your 

 own because the local dealers carry only certain sizes and makes. 



6. For the casual tourist a 3 A Special Eastman Kodak is good 

 enough for all ordinary purposes, and films must be carefully 

 protected against dampness. 



