NOTES ON THE PERFORMANCE OF THE S. S. TYLER. 91 



NOTES ON STANDARDIZATION. 



1. After run No. 6, the vessel hauled off to await the change of the tide from 

 flood to ebb; 2% hours elapsed between end of No. 6 and beginning of No. 7. 



2. Runs Nos. 7 and 8 were thrown out in plotting the speed and power curves ; 

 it was noticed that the tide had not set down and was still running oblique to the 

 course. It is to be noted that the revolutions and power spots check well, but the 

 speed is evidently not correct; the slip curve also bears this out. 



3. Four high-speed runs were made and a mean of means taken ; this estab- 

 lishes the top spot beyond question. 



4. On run No. 9, the Tyler and the Narragansett passed on the course, one 

 to the west and the other to the east of the buoys ; it is probable that each affected 

 the other slightly. 



5. On run No. 10 it is to be noted that the steam pressure dropped back and 

 consequently the indicated horse-power fell about 100 below the average for the 

 other three high runs. Full pressure would have made the top speed 12.875 knots. 



Table 3. 



Propulsive Efficiency. 



From the above data the efficiency figures are as follows, taking the ratio be- 

 tween total effective and indicated horse powers : — 



Displacement, draught, etc., will be found in Table i. 



It will be noted that at top speed the propeller shows no signs of breaking 

 down. 



DISCUSSION. 



The Chairman : — I hope this paper by Mr. Rigg, entitled, "Notes on the Performance 

 of the S. S. Tyler," will receive an adequate discussion. 



