42 SEALS OF THE SHETLAND ISLANDS. 



mal could hardly contrive, at perhaps twenty or thirty yards, 

 to get so rapidly all his body out of the course of the ball : 

 perhaps guns that shoot wide of the mark would have the 

 best chance of defeating the intention of this manoeuvre, and 

 a curious inference might then arise, novel to Manton and 

 Oakleigh, that in shooting at swimming seals the gun must 

 either be very good or very bad — no medium. I remember 

 an old self-taught blacksmith remarking, that there was no 

 gun but would shoot well with some kinds of charge ; and 

 I may add, that there is none that do equally well with all. 

 In the kind of powder, but not so much in the quantity for 

 a charge, we must be very precise, and sufficiently numerous 

 trials must, as a pre-requisite, be made of its suitableness to 

 the gun before each hunting excursion. We can never say 

 beforehand what kind of powder or charge will suit, but 

 often low-priced blasting or coarse cannon powder is pre- 

 ferable to the finest Dartford, and that sort which will ad- 

 mirably agree with a gun one day may in two or three days 

 afterwards be totally unfit, and again recover its quality. 

 This mutability may sometimes, no doubt, be ascribed to 

 changes in the state of humidity to which this climate is so 

 much exposed ; but even when every precaution against this 

 cause of deterioration has been taken, and the weather con- 

 tinues steady and serene, the powder changes in its quality. 

 At other times, under every carelessness and all states of 

 moisture in the air, it remains true — perhaps some minute 

 and obscure chemical or electrical action is the cause of its 

 variability — or perhaps, as I have sometimes thought, it is 

 not always the powder that is at fault, but the cause of 

 error may be found in certain states of refrangibility of the 

 air leading to false aim, or in differences of density in dif- 

 ferent portions of air in the course of the ball's transit. A 

 strong wind blowing across the direction of a ball also 



