plate with a solid substance which would wash away in the turbulent region and would 

 remain on the plate in the laminar region. 



In regions of transition, and just preceding transition, we noticed a regular and 

 very fine pattern of streamwise striations, perhaps of the order of a millimeter distance 

 apart, these distances considerably less than the distances between the studs, and 

 apparently not much depending on the stud distance. 



This experience suggests that in order to determine whether the boundary layer 

 streaks are really connected with film behavior it might be instructive to perform 

 further observations in water using the aforementioned technique. 



407 



