Predicting the future for Agricultural Aviation is rendered even more uncertain than predictions for most forms of aviation because in this case the future depends on two entirely separate sets of unknowns. These are the normal unknowns affecting aeronautical development but, more important, there are the unknowns affecting the development of agricultural chemicals. Also, in predicting the future evolution of any activity one must normally look back over the rate and the trend of developments in the activity, so far as they are relevant, from the past and then project this rate and trend into the future, bending and extending the line of projection in accordance with known or foreseeable influences. Here again we get a third set of unknowns related to future farming techniques, although these unknowns are perhaps less significant because the main expansion in agricultural aviation will probably lie in the vast undeveloped regions of the world where the farming techniques will merely be brought up to present standards, or just introduced where there was literally no agriculture before.