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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 62 



plate was then compared with the velocity indicated by the Pitot 

 tube under test. Comparisons were made at a number of speeds for 

 each tube. 



Fig. 6. — Comparison of three forms of Pitot tube. Each point represents 

 one observation, and serves to bring out the sensitivity of the Pitot tube and 

 manometer measurements employed. 



It was demonstrated that the velocity is correctly measured by any 

 tube having an easy entrance and a long cylindrical portion parallel 

 to the wind in which a number of small holes are drilled to transmit 



