Cramp, Measurement of Air Velocities. 



and the end n faces the current, the stream lines passing 

 the tiny holes // must be parallel with the tube, and little 

 induction effect is to be anticipated. 



As a general result it may be stated that the side 

 gauge and the Brabbee tube read practically alike 

 throughout, and their readings are therefore placed in one 



«H 



lAVERS OF GADZE. 



P'g- 3- 



column. Again, Nos. i and 2 read practically alike 

 throughout, and they are accordingly placed together. 

 No. 3 was never as good as either i or 2, and its readings 

 are therefore omitted. The Nipher collector was found 

 to be so inaccurate that its use was abandoned. An 

 example of the readings obtained with it is, however, 

 given below. All the preliminary tests are omitted from 

 the following tables, which simply give sample tests 

 showing the order of the differences obtained. For each 

 table the slides at the fan inlet and outlet were carefully 



