12 



wviitmmt- 



■ RECORD/NG DRUM! 



RECORDING PEN 



recording paper. Pin points were projected through small holes in the 

 recording drum so as to perforate the recording paper at time intervals 



equivalent to one hour (prototype ) , 

 to maintain a permanent time check 

 on each record. The recording 

 gages were mounted on flat base 

 plates, which in turn were mounted 

 on tripods permanently located at 

 all points in the model at which 

 hurricane tide data were desired. 

 The tripod mounts were all adjusted 

 to a common reference plane, so 

 that any recording gage could be 

 moved from one location to any 

 other location without loss of 

 time for adjusting its reference 

 plane. One of these recording 

 gages is illustrated on fig. 7- 



19. Manually operated point 

 gages, permanently mounted at the 

 locations of all prototype tide 

 gages and at a number of additional 

 locations, were used for measure- 



Fig. 7- Model recording tide gage 



ment of astronomical tide elevations during most of the model tests; 

 however, the recording gages described above were used for this purpose 

 during a few tests in which time did not permit use of the point gages. 

 More precise measurements were possible with the point gages than with 

 the recording gages, since the measurement was a direct one and did not 

 involve interpretation of a record. One of the permanent point gages 

 used may be seen on fig. 3. 



20. Most of the measurements of current velocities in the model 

 were made with miniature Price-type cixrrent meters illustrated on fig. 8. 

 The horizontal dimension of the cup wheel was about O.O83 ft and the 

 vertical dimension about 0.03 ft. The meters were capable of accurate 



