638 



ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1911. 



The foregoing are the record speeds so far obtained of mechanical 

 locomotion, and it will be interesting to see what are the record speeds 

 attained in the other elements. Until the other day, as Mr. Parsons 

 told us in his lecture, the speed on water which has never been ex- 

 ceeded was that of the ill-fated turbine boats, Viper and Cobra, of 

 about 43 miles an hour. The ship which at present holds the record 

 for speed is the torpedo destroyer Tartar, built by Messrs. John Thorny- 

 croft; this, under Admiralty tests, giving a speed of 41 miles an hour. 



The diagram (fig. 4) shows in an interesting manner what the 

 progress in speed has been for this class of boats during the last few 



eo 



55 



50 



45 



40 



O 

 I 35 



30 



25 



20 



1870 



lM*Plt LEAF3E 

 (»q) 



MIRANDA IS 



\M 



1690 



YEAR 



FIG. 4.— Speed records for Thornycroft warships and motor boats. 



years, and may be taken as typical, and about which curves Sir John 

 Thornycroft writes as follows : 



I do not think the curve would be materially altered if vessels of other builders were 

 brought in, although there would naturally be more points on it. 



I am able, however, to give you the results to-night of something 

 which has altogether put in the shade even-the speeds of the two first- 

 mentioned boats. This has been attained by a boat which, though 

 corresponding in some respects with previous hydroplane boats, has 

 been designed by Sir John Thornycroft to possess a certain amount 



