224 



ANIMAL MECHANICS 



Transverse Tension due to Abdominal Muscles. 



Rectus abdominis, o.ooo 



Obliquus externus, 0.082 



Obliquus internus, Q-I37 



Transversalis, 0.150 



0.369 



From the preceding results, it follows that the transverse 

 strain at the navel is 58.57 per cent, of the longitudinal 

 strain — 



Transverse strain q6o x 100 n 



. _ = I—* = 58.57 per cent. 



Longitudinal strain 630 



At p. 161, I have given the measurements of the abdomi- 

 nal curvatures of three young men, when the abdomen was 

 distended to its utmost extent. From the mean of all three 

 we obtain, in the case of young men, the result that the dia- 

 meter of the transverse circle of curvature is 55.58 per cent, 

 of the diameter of the longitudinal circle of curvature — 



Transverse diameter 12633 x 100 

 Longitudinal diameter 22727 55.57 per cen. 



As it was desirable to ascertain the amount of curvature 

 of the abdomen, at the time when its muscles are used in the 

 act of parturition, I obtained the following measurements of 

 five healthy women, taken at the commencement of labour. 

 I instructed the head midwife of Sir Patrick Dun's Hospital 

 Maternity to measure for me, with tape, the following quan- 

 tities : — 



1. Height of woman. 



2. Girth transversely round navel. 



3. Length of curved arc from the end of the sternum to 

 the top of the symphysis pubis. 



