212 



REPORT — 1879. 



Both tubes were fixed in the upright side of the ship (of course nicely 

 square to the plating) between 2 and 3 feet below the water level, and a 

 little way abaft the midships. [The Iris, it should perhaps be stated, is 

 300 feet long, 46 feet beam, 18 feet mean draught (on trial). She has 



Dl RECTI on of] 



MOTION OF 



TUBE 



ZERO .HOLE 



Fig. 1.— Tube A. 



PRESSURE 

 HOLE 



DIRECTION OF 

 MOTION OF 

 TUBE 



ZERO HOLE 



Fig. 2.- Tube B. 



Cross-sections of tubes A and B, half size. 



exceptionally fine lines for her length, the ratio of displacement to circum- 

 scribing cylinder being only -54.] Tube A was 9 inches further forward, 

 and also 9 inches nearer the water surface, than tube B. Both tubes 

 worked in stuffing boxes, and could be set so as to project any desired 

 distance from the side up to about 23 inches. 



