INTRODUCTION. 7 



these were reserved for distilling water, and were seldom 

 used for steaming except in cases of emergency, and it 

 was my usual custom during the cruise to use only two 

 boilers when steaming, as this number was found suffi- 

 cient under favorable circumstances to drive the vessel 

 six knots an hour on a daily consumption of six tons 

 of coal. 



The superiority of good bituminous coal for the work 

 of sounding was clearly demonstrated. After many 

 experiments it was proved that the most economical way 

 to sound was to start fires for each cast, unless more than 

 two were to be taken in twenty-four hours, and to haul 

 fires as soon as the cast w^as finished, although for par- 

 ticular reasons fires were sometimes permitted to die 

 out instead of being hauled. When anthracite coal was 

 used, fires had to be kept banked between casts, which 

 prevented the use of the mainsail, because with the 

 smokepipe lowered (its usual position when cruising) 

 the wind which was forced down the funnel would put 

 out the fires ; while with the smokepipe raised the main- 

 sail could not be set. With bituminous coal, however, 

 the mainsail could be used twenty hours out of the 

 twenty-four, because fires were hauled as soon as the cast 

 was taken. 



Under favorable circumstances it required only about 

 one-half ton of Cardiff coal for each cast, hence we 

 invariably purchased soft coal after leaving the United 

 States. 



One thing more is worthy of note, viz. : notwith- 



