THE PROGKESS IN STEAM NAVIGATION. 575 



ship. These eircuin.stance.s, in association with the small load carried 

 explain the apparent gain in speed of the smaller vessel in relation to 

 ner dimensions. 



INCREASE IN SIZE AND SPEED OF WAR SHIPS. 



Turning- from seagoing ships of the mercantile marine to war ships 

 one hnds equally nota])le facts in regard to increase in speed, associated 

 with enlargement in dimensions and advance in propelling apparatus, 

 materials of construction, structural arrangements, and from. Tj) to 

 1860 a measured-mile speed of 12 to 13 knots was considered sufficient 

 for battle ships and the largest classes of cruisers. All these vessels 

 possessed good sail power and used it freely as an auxiliary to steam 

 or as an alternative when cruising or making passages. When 

 armored battle ships were built, 1859, the speeds on measured-mile 

 trials were raised to 14 or 14i knots, and so remained foi- about 

 twenty years. Since 1880 the speeds of battle ships have been gradu- 

 ally increased, and in the latest types the measured-mile speed required 

 is 19 knots. Up to 1870 the corresponding speeds in cruisers ranged 

 from 15 to 16 knots. Ten years later the maximum speeds were 18 to 

 181" knots in a few vessels. Since then trial speeds of 20 to 28 knots 

 have been attained, or are contemplated. There is, of course, a radical 

 distinction between these measured-mile performances of war ships 

 and the average sea speeds of merchant steamers above described. 

 But for purposes of comparison between war ships of different dates 

 measured-mile trials mav fairly be taken as the standard. For long- 

 distance steaming the power developed would necessarily be much 

 below that obtained for short periods, and with everything at its best. 

 This is frankly recognized by all Avho are conversant with war-ship 

 design, and full}^ allowed for in estimates of sea speeds. 



On the other hand, it is possible to point to sea trials made with 

 recent types where relatively high speeds have l)een maintained for 

 long periods. For example, the battle ship Royal Sortreltjii has main- 

 tained an average speed of 15 knots from Plymouth to Gil»rallar and 

 the lienown has maintaincnl an equal speed fi-om Bermuda t(» Spit head. 

 As instances of good steaming by cruisers, reference may l>e made to 

 60-hour trials with the Tetrihle, when she averaged over 2(» knots, antl 

 to the run home from Gibraltar to the Nore by the ])iiuhii>, when she 

 exceeded 19 knots. Vessels of the /Wwv/.v class, of only 2. loo tons 

 displacement, have made long runs at sea averaging ovei- IT knots. 

 Results such as these represent a substantial advance in ^\^vvK\ ..t" Her 

 Majest3''s ships in recent years. 



Similar progress has been made in foreign war ships built abroad Jts 

 well as in this country. It is not proposed to give any facts for these 

 vessels or to compare them with results (.htained by sinuMar classes of 

 ships in the royal navy. Apart from full knowledge of the comlitii.ns 



