FRENCH IRON-CLAD SQUADRON. 



201 



4. "3 7 on each quarter, and this was previous to the I'edistribution at Funchal of 

 the Normandie's loading. Compared wilh the Invincible, the amount of the total 

 difference is no more than 6.°4'7, or only 3.° 18 on each quarter. The observations 

 ■which had already at different times been made on the number of rolls correspond- 

 ing to each vessel, were continued on this day, and gave the following number per 

 minute : Solferino, 9| ; Magenta, 10 ; Napoleon, \(}\ ; Tourville, lOf ; Couronne, 12 ; 

 Invincible, 12 ; Normandie, 12^; Talisman, IS. These figures are very nearly the 

 same as had been observed under very different circumstances of weather and sea, 

 notably on Sept. 28th. In the various notes communicated to me, I observe that 

 attention is particularly called to this almost constant recurrence of the same 

 numbers. t)ne of them, written by a most distinguished officer, contains a sen- 

 tence which I will quote verbatim. " These numbers are sensibly constant for 

 the same vessel, whatever be the magnitude of the rolls, from the least to the 

 greatest. I have observed it repeatedly." Eut one day occurred (probably an 

 exception) which totally upset the order of classification determined by the 

 greatest mean. On "Wednesday, 18th Nov., after the departure from Funchal, the 

 •squadron were steering N.E,, with two furnaces in blast up to 3 p.m., and then 

 with three till evening, and a light breeze between S. and S.E. was blowing on 

 the quarter beam. With the help of its sails, it attained in the morning a speed 

 of 7 or 8 knots, and in the evening 8 or 9. The weather was very fine, and the 

 sea quiet, with only a long and gentl e swell on the beam. Under these circum- 

 stances (and I think it of use to particularise the details because it touches on a 

 problem in navigation, very curious and little known) the magnitude of the rolls 

 observed from hour to hour were as follows : 



The result of this table is to class the ships in the following order of increasing 

 •magnitude of roll, for the 12 hours : Invincible, 7°.33 ; Couronne, 8.12 ; Magenta, 

 8.58 ; iV^ormandJe, 9-S3 ; Solferino, 9-37; Napoleon, ^.8Z ; Tourville, \1.08. 



The abundance of these details will I hope be excused, but as they have never 



before beeu studied with such care and completeness, and as they tend to throw 



a new light on one of the most important abd most controverted questions of 



Tiaval architecture, I have thought it necessary to enter into them. Now let 



Vol. IX. o 



