12 



ANIMAL MECHANICS. 



immediate and painless death. In hanging, the rope supports 

 the atlas, and presses it against the occipital articulations, while 

 the second vertebra tends to fall with the body ; and it follows 

 from this that either the odontoid process must give way, or 

 the second vertebra be broken across at its superior articu- 

 lating surfaces ; in either case death will be immediate. The 

 height of the criminal just mentioned was 5 ft. 9 J in. a few 

 days before execution, and after death he was found to mea- 

 sure 5 ft. 11 in., having been elongated an inch and a half by 

 the " long drop" of 14J ft. 



From the foregoing, it therefore appears that a shock to 

 the neck of 2240 ft. lbs. is just sufficient to cause immediate 

 death. Substituting, therefore, 2240 ft. lbs. for the work lost 

 in the preceding equation, we find 

 PQh 



or, solving for P, 



From this equation it follows that, unless Qh be greater than 

 2240, the value of P (the weight required) will be negative ; 

 but Qh denotes the work produced by the criminal Q falling- 

 through the height h. 



Let h, therefore, denote the " long drop" found by Rule I., 

 and the following consequences may be inferred from (4) — 



1 . In the American mode of hanging, if the weight be let 

 fall through the height h, sufficient to cause death instanta- 

 neously by the " long drop," it would require an infinite weight 

 to cause immediate death ; for in this case 



Qh- 2240 = 0, 



and therefore P is infinite. 



2. In the American mode of hanging, if the weight be 

 let fall through twice the height of the "long drop," a weight 



