Lesley.] 3g4 [April. 



steamer, found that the next longest voyage of the Canada had been 

 its first. He stated that all the voyages from Liverpool to New York, 

 commencing about the 9th of January, were longer and stormier than 

 the others. In 18G3 the corresponding voyage made by the Europa 

 had been one of 21 days. That of the America in 1862 had also 

 been one of 21 days. The succeeding voyage is always considered a 

 good one, not as against a prevalent west wind, but as against gales. 



The avcrcKje time of endurance of each gale was 26 hours, and 

 the average interval of comparative calm was 6 hours. If 60 miles 

 an hour were given as the speed of the wind, and this were con- 

 sidered to mark the speed of the vortical column, we would be 

 obliged to consider the distance between the centres of the gales as 

 about 2000 miles, and there could have been but one gale traversing 

 at anyone time the distance between the Banks and Ireland. There 

 would be sufficient room, therefore, for it to assume any magnitude, 

 however great. But the fair weather on the British provincial 

 coast, as has been already said, seems to prove the small diameter of 

 all the gales, and we must view each one, therefore, as making its 

 solitary journey, as a simple eddy, nearly along the northern margin 

 of the Gulf Stream, and probably enlarging its area as it advanced ; 

 which would account for the extreme violence of the gales we en- 

 countered last as compared with those encountered in the first part 

 of the voyage. 



But of course, the rate of motion of the nucleus cannot be fairly 

 represented by the rate of motion of any given circle on its limb, 

 unless that particular circle be selected at just the proper distance 

 from the centre, to be a mean between the dead wind at the extreme 

 circumference and the excessively rapid rotation at the centre. In 

 some one of these gales, it is probable, that the ship's course did cut 

 such a circle of mean motion, and got (without, of course, knowing 

 it) the exact rate of the vortical, in the actual rate of the blast over the 

 deck. It is a great mistake to draw a vortical storm with the shape 

 which it would have if it had no body-movement forward and moved 

 in vacuo. The fact must be, that most of the sections of a cyclone 

 move forward with its nucleus in nearly parallel lines; and that the 

 storm as a whole, while theoretically vortical, is in practice linear. 

 It practises its gyrations only near its centre. 



The form of such a gale, moreover, must be merely a form, like 

 the form of a wave, the vortical movement being impressed on suc- 

 cessive portions of air, which, after being in turn set moving, are in 

 turn allowed to stop, fall into the rear, and come to rest. 



