11 



pound charge is considered very good. Measurements of heat flow through the 

 sea floor, although somewhat difficult experimentally, are straightforward in 

 interpretation because of the relatively uniform and constant temperature of the 

 bottom waters over large areas of the oceans. In contrast, it is extremely 

 difficult to obtain unequivocal determinations of heat flow on land because of mi- 

 grating ground waters, uncertainties introduced by the circulation of drilling 

 fluid in wells, and changing atmospheric temperatures. In magnetic and gravity 

 measurements, the ability to use the sea surface as a reference plane and the 

 simultaneous recording of a bottom depth profile considerably facilitate inter- 

 pretation. 



Moreover, experimentation does have its place in oceanographic investi- 

 gations, particularly model experiments in which processes are studied on a 

 reduced scale, and the conditions are varied, one by one, to establish a frame- 

 work of analogy by which the full scale phenomenon may be better understood. 



Perhaps more than any other scientific field, oceanographic research 

 demands teamwork between scientists of different backgrounds and abilities. 

 The classical method of experimental research in physics involves design of a 

 critical experiment, a great deal of work in developing apparatus and in estab- 

 lishing rigorous control of the conditions, and a few careful measurements, all 

 done by one or two workers. In geophysics it is usually necessary to take a 

 large number of observations, both to obtain sufficient detail and to find a few 

 simple situations where nature has "controlled" extraneous conditions so that 

 we can gain understanding of underlying processes. An oceanographic instru- 

 ment may therefore be used by many people who were not involved in its design 

 and development, often for purposes quite different from those which motivated 

 the designers. The recording echo-sounder is a pre-eminent example, for its 

 use requires the background and insight of the geologist while its development 

 demands the ingenuity and skill of electronic and mechanical engineers. Simi- 

 lar statements can be made about the whole range of oceanographic instruments 

 described in this symposium, but a great deal of wasted effort results if the de- 

 velopment of instruments and their use are not closely coordinated. Many in- 

 genious gadgets have fallen into the limibo of disuse or have failed to achieve 

 their full potentialities simply because of lack of mutual understanding between 

 the developers and the users. It is sometimes argued that every research 

 oceanographer should develop his own equipment, but I believe this would lead 

 to a mass of spotty and unrelated observa.tions which could not be synthesized 

 into any significant model of the real earth. Even though it may violate the in- 

 dividualistic traditions of science, teamwork is the essential prerequisite for 

 broad advances in geophysics. 



DISCUSSION: A. C. Vine 



All too often in conferences the papers presented are limited to a few of 

 the technical accomplishments of the past year while discussion of the exciting 

 techniques and problems of the future are relegated to conversation during lunch 

 hour. Dr. Isaacs' paper has reversed the usual procedure in a way which pro- 

 vides a good omen for this symposium. In discussing his paper and the prob- 

 lem I can but echo his desire to concentrate on the novel approaches, the princi- 

 ples involved and the fundamental problems. 



First, I would like to emphasize John Isaacs' statement that, historically 

 knowledge and instruments have played leap frog with each other in a haphazard 

 fashion. How often theorists and experimentalists have wasted their time argu- 

 ing about which of their specialities is the most important when neither side 

 knew if it was half a cycle ahead or behind the other. This is not to be inter- 

 preted that frequent and heated debates are not in order on whether oceanography 



