8 



measuring or structural portion of the instrument alter the characteristic of the 

 sample. Here we must guard against over-instrumentation. For example, it 

 is obvious that a listening device may produce noise if the noise falls outside the 

 band received. By some similar mechanism a dog is able to detect extremely 

 small quantities of material by his olfactory sense, although he carries an un- 

 usually high olfactory background around with him. In addition to sensitivity 

 to unwanted factors, the instrument also should not basically lose or confound 

 information by responding to unwanted functions of the desired factor. This is 

 a common failure of instruments, and some have persisted undetected for con- 

 siderable tirne. An example is a transport measuring device which to a degree 

 integrates V . 



It is common for the sensing element to relate the desired-parameter to 

 electrical energy or mechanical energy. This is then"amplified" by adding 

 quantitatively related energy or by altering some characteristic so that it is 

 outstanding. Normal vacuum tube amplifiers add quantitatively related electri- 

 cal energy. Thermometers, balances, scales, and calipers accentuate posi- 

 tion. Filters, feedbacks and a tremendous variety of components are inter- 

 polated in the energy path at this point, and are best discussed by others. I 

 would like to state, however, that in the introduction of these into an instrument 

 system there is the greatest need for discretion and common sense for here lies 

 the opportunity to produce either light or darkness. 



We might liken this part of an instrument to a small path through a 

 meadow which is suitable for limited travel. The introduction of powerful ma- 

 chinery for its improvement can either turn it into a morass or into a highway 

 depending upon discretionary powers of the workers. 



We finally arrive at the medium toward which man's curiosity is vented 

 --the sea. Here his instruments have evolved as a product of environment inas 

 real a fashion as have the organisms of the sea. 



It is interesting to consider the effect of the nature of the sea on instru- 

 mentation by connparing the characteristics and consequent instrument evolution 

 in the case of the exploration of the physical realms of oceanography, geology, 

 meteorology and astronomy. The analogous and homologous instruments and 

 tools in these realms frequently resemble one another so little as to be almost 

 unrelatable. A discussion of this is interesting but let us consider only one ex- 

 ample of analogous instruments for transport measurement: in oceanography, 

 the reversing thermonaeter and Nansen bottle; in meteorology, the barometer; 

 in geology, topographic surveys; in astronomy, instruments of spectroscopic 

 doppler and photography. The same also is true of the homologous instruments 

 for instance, the physical probe: - the lead, cable, and winch in the sea; the 

 free balloon or rocket in the atmosphere; the drill and string of tools in the 

 earth; and for astronomy, only the implications of hydrazine hydrate. 



First, some things floated and some sank in the ocean and because of 

 the ocean's intermediate density man early devised tools to move upon its sur- 

 face and to probe its depth. The students of the other media did not have this 

 singular advantage, but the oceanographers, like happy natives with a bountiful 

 provender, have been content with their initial tools and have only under com- 

 pulsion utilized techniques of exploration that were borrowed in principle from 

 those students of nature less fortunately endowed, and who were pressed to de- 

 velop other exploratory methods. I believe that we still are somewhat circum- 

 scribed by our ships, line and lead. 



Second, the ocean is large, and man could explore only small parts of it 

 that were immediately accessible. Exploration of the larger areas still re- 



