ON THE CHOICE OF SHOT GUNS 43 



figures the length of the shot column can only be got at by 

 making some use of a comparison between shots fired at one 

 range and those fired at another. In other words, the length of 

 shot column approximately found, as described, when divided by 

 the difference of time between first and last pellets, brings out 

 the average velocities of the shot column, at the instant of the 

 leading shot striking the target, too high. That is to say, the 

 previous length of column having been found too much, is 

 taken merely as a basis, to indicate the position in the rear at 

 the length of the column away from the target at which to 

 search for the speed of the lagging pellets, and, with these 

 found, and the speeds of the leading pellets already found, 

 from the table upon page 41, the average speed has been dis- 

 covered, and actual time between first and last being known, 

 the length of column has been re-found in a way that must be 

 as accurate as any records can be that are based on two 

 different discharges and the chronograph. 



Taking the length of the column of shot, it is clear that the 

 difference of time in seconds between the first and last arriving 

 pellets, divided by the length of the column in feet, will give 

 the mean velocity of the shot column at the instant the first 

 pellets struck the target. The amended figures are tabulated 

 on the next page. 



It has lately been attempted to show that Mr. Griffith's 

 measurements are not supported by the results on a target 

 passing at 75 feet a second at right angles with the line of 

 fire. But this speed is not enough to prevent the irregular 

 spread of the shot pellets from misleading. In other words, 

 the faster the movement of the target the less will the elonga- 

 tion of pattern depend upon the accident of pattern, and the 

 more it will depend upon the length of shot column and 

 its speed. Besides this, birds at 75 feet per second are not 

 the difficult sort that people want to learn to kill in a 

 wind. 



In the following table it is seen that in one case the 

 column is no longer at 50 yards than at 40 yards, and we 

 may be quite certain shot columns are not so in reality: 



