330 THE VOYAGE OF H.M.S. CHALLENGER. 



The definiteness of the characters of these, and the amount of specialisation they 

 show, indicate not only a great antiquity for the whole group, but also the great amount 

 of extinction that has gone on amongst its members in the past, in the process of which 

 nearly all the intermediate and less specialised forms have disappeared." 



The Ckozets to Kerguelen. 



On the 4th, 5th, and 6th January the ship was running before a northwest gale 

 for Kerguelen Island, the velocity of the wind, which was fairly steady in strength, being 

 30 miles per hour, the waves varying from 18 to 22 feet in height from hollow to summit, 

 and 420 to 480 feet in length from crest to crest. So far as was determined, the 

 wave undulations had a velocity of 29*5 miles per hour, very nearly equal to that of the 

 wind. 



The length of the waves was measured by veering a canvas balloon called a Burt's 

 nipper astern until it rose on the crest of the advancing wave at the same moment that 

 the ship's stern was on the crest of the wave preceding it ; the height was estimated by 

 the observer taking up such a position in the ship that when in the trough of the sea 

 his eye could just see the horizon over the crest of the wave nearest the ship ; the 

 speed of the undulation 'was calculated by the number of waves that passed the ship 

 in a given time, allowing for the velocity of the ship through the water, and the length 

 of waves, which for this purpose was assumed as 450 feet. To these undulations the 

 Challenger rolled through an arc of from 25° to 50°, that is, from 12° to 25° each side 

 of the perpendicular, 5 to 5 J rolls per minute, the average speed through the water 

 being 9 knots per hour. 



The weather during these three days was fairly clear, passing showers of rain or snow 

 were occasionally experienced, and as Kerguelen Island was approached the temperature of 

 both air and sea decreased to 39°, a good preparation for the cruise southward towards the 

 ice. Notwithstanding a gratuitous issue of warm clothing the sick list amounted to 

 twenty-four, due principally to colds (a large percentage) ; the stokers felt the cold most. 



Owing to the strong wind and high sea the ship neither sounded nor dredged, a matter 

 of considerable regret to all, as it would be most interesting to know the depth of the 

 channel that separatee the Crozets from Kerguelen Island. It will be seen, however, by 

 referring to the Chart of the World which accompanies this narrative, that the depth is 

 assumed as being greater than 1000 fathoms. 



On the 6th January, at noon, Bligh's Cap was 74 miles off. Such was the confidence 

 in the determination of its position by Captain Cook that, like Sir James Ross, notwith- 

 standing the misty state of the weather, the ship ran straight towards it, and at 7 p.m. 

 it was observed ahead. At 8 p.m. Bligh's Cap being S.E. by E., about 5 miles distant, the 

 ship was brought to the wind under double-reefed topsails for the night. At this time 



