RESEARCH FOR AERONAUTICS—-FARREN 265 
in ideal conditions. But it is doubtful whether this is a wise policy, 
since we can hardly expect to define or to maintain the shapes of 
surfaces sufficiently closely. Power-operated controls have been 
avoided so far, but it is unwise to assume that we can neglect them 
indefinitely. There seems to be no good reason to be doubtful of our 
ability to make them reliable. 
POWER-PLANT DEVELOPMENTS 
I do not propose to extend this survey to the two other main factors 
that have contributed to the changes we have seen in aircraft—the 
power plant and the propeller. I have already quoted some figures 
that show how remarkably the reciprocating engine has advanced. 
I have also said that there have since been further advances, which, 
however, serve rather to emphasize the comparisons I have made than 
to invalidate them. This is because there have been accompanying 
changes in weight and other characteristics that leave the main con- 
clusions substantially unaffected. Our debt to the engineers who, 
aided by research, have achieved these results is immense. 
To the constant-speed propeller the performance of aircraft must 
also acknowledge a great debt. But the flying man is even more 
grateful for what it has provided—almost complete freedom from his 
chief anxiety, namely, the liability to misuse his engine. We now look 
forward confidently to new methods of propulsion for aircraft. But 
I believe the propeller has a long and useful future before it and one 
in which research will play an outstanding part. 
SUMMARY—THE TASK OF RESEARCH 
I trust that this short survey has gone some way to show why I am 
convinced that the research worker and the engineer must work to- 
gether if we are to make significant progress. In his James Forrest 
lecture to the Institution of Civil Engineers in England, Dr. Southwell 
said that “Aeronautical engineering is ordinary engineering made 
more difficult.” If that was true in 1930, as I believe it was, it is more 
than ever true now. We can see clear prospects of great advances in 
aircraft in size, in performance, and in safety. The curve of improve- 
ment against time shows no real signs of flattening out. But we shall 
need all our ingenuity to avoid or to overcome the barriers which we 
can see ahead. 
I think the engineer has made good use of the outstanding contribu- 
tions of research for aeronautics. If at times he has appeared slow to 
appreciate the significance of new developments, he has a good excuse 
in his preoccupation with producing something on which we can rely. 
This is a sufficiently serious responsibility and one that he has borne 
with credit. But it is this very preoccupation that emphasizes the need 
