30 



Scientific Proceedings, Royal Dublin Society. 



Now, assuming that equal weights of shot of different sizes 

 acquire the same muzzle velocities, we get for — 



. No. 1 shot = 71 to the oz., . . ' W == '000887. 

 Velocity at muzzle, 1270 f. s. Energy. 



20 yards, 

 40 

 60 

 80 

 90 

 100 



956 

 777 

 654 

 565 

 529 

 497 



12.49 lbs. 

 8-24 „ 

 5-84 „ 

 4-35 „ 

 3-82 „ 

 3-37 „ 



Again, for — 



No. 9 shot, 568 to the oz., . . W 

 Velocity at muzzle, 1270 f. s. 



•000011. 



Energy. 

 1-03 lbs. 

 •545 „ 



•478 „ 

 •422 „ 



The computed velocity here obtained for No. 9 at 20 yards is 

 •16 f. s. in excess of the velocity at that distance of the smallest size 

 English shot used in my experiments. This is probably due to the 

 smaller shot encountering more friction in its passage through the 

 barrel, and so losing muzzle velocity. We may conclude, thercr 

 fore, that the results obtained above for various-sized shots rather 

 under-estimate the differences of velocity between equal weights of 

 large and small shot propelled by same charge of powder. 



The velocity of 634 f. s., at 40 yards for No. 7, was found to 

 agree closely with the results of a calculation made from the 

 observed motion of the Field Force Grange when struck by the shot 

 at that distance. 



From an examination of the remaining velocities and energies 

 in these Tables, the great advantage of using heavy shot for long 

 range is very apparent. Starting at 1270 f. s., the No. 7 shot has 

 at 40 yards lost half its speed, and at 60 is reduced to -fths. The 

 No. 1 retains half to nearly 60 yards, and -fths to nearly 100 yards. 

 The No. 9, on the other hand, is reduced to half at 32 yards, and 

 to fths at about 48 yards. The contrast between the energies 



