- 3 - 



the flooded model, as many hydraulic occurrences as possible were 



y 



compared with data from the detailed field reports of H. A. Marmer, 

 and observations by V. H, Brogdon and the writer. With few adjust- 

 ments of the model the times of slack water, the occurrence of high 

 and low water, the particle excursions, and magnitudes of velocities 

 were reproduced at a large nvimber of points. 



Auxiliary equipment was designed to reproduce tides, winds, 

 rainfall and industrial discharge scaled in accordance with the 

 model constants. 



The tide machine was composed of three drums, each of which dis- 

 placed water and changed sinusoidally the water level in the model 

 at rates in accordance with the time scale 1/1440 (one minute per 

 model "day")» Each drum was driven by a scotch yoke through a 

 stroke of 2 inches; the semi-diurnal drum having a displacement 

 determined by the sum of the amplitudes of the M2, S2 and N2 tidal 

 components and a speed number of the average of the component speed 

 numbers, the first diurnal drum a displacement determined by the 

 amplitude of the O^^ tidal component and a speed number of the (>j_ 

 component, and the second diurnal drum a displacement proportional 

 to the sum of the K^ and ?]_ tidal components and driven at the 



1/ The Tide in Barataria Bay . U. S. Coast & Geodetic Survey, 

 Washington, D. C, July 1947. 



The Currents in Barataria Bay . U. S. Coast & Geodetic Survey, 

 Washington, D. C, February 1948. 



