A good account of cavitation in this period may be found in the book 

 "Cavitation" (Knapp et al. 1970) through about 1969. This, together with 

 the volume "Cavitation State of Knowledge," provides an excellent summary 

 to that time. In the present context, some of the events of this period 

 that seem significant are summarized in Table 1. This tabulation stops 

 in 1969 deliberately to emphasize progress made since then. 



TABLE 1 - SOME CHRONOLOGICAL EVENTS IN 

 CAVITATION INCEPTION 



1947 Knapp' s movies of growth and collapse of travelling 

 bubbles 



1949 Plesset's analysis of bubble motion 



1953 Parkin and Kermeen - Boundary Layer Inception 



1955 Plesset and Zwick - Vapor Bubble Dynamics 



1956 Daily and Johnson - Shear Flow Inception 

 1959 Ripkin and Killen - Nuclei Measurements 



1962 van der Walle - "Stabilized" Bubble Cavitation 



1966 Johnson and Hsieh - Bubble Screening 



1966 Schiebe - Cavitation Occurrence Counting 



1966 Lindgren and Johnsson - ITTC Comparative Tests 



1969 Holl and Kornhauser - Thermodynamic Effects on 

 Scaling Inception 



1969 "Cavitation State of Knowledge" 



One of the most influential events of this tabulation is the experi- 

 mental work of Parkin and Kermeen (1953) . They focus more sharply 

 on the small bubbles seen within the boundary layer of smooth bodies as 

 this appeared to be the crucial region of flow. Their impressive photo- 

 graphs showed that, on a hemispherically nosed body, the region of visible 

 cavitation was preceded by a region of "microscopic cavitation bubbles 

 which grow in the boundary layer." Figure 2, taken from their report, 

 shows these small bubbles upstream of the more readily visible macroscopic 

 cavitation. Also shown on the figure, is their interpretation of the flow 



