Manchester Memoirs, Vol. Iv. (191 1), No. 7- 19 



body, relative to the surrounding water, in the opposite 

 direction to that of rotation. Each of these secondary 

 phenomena gives rise to a tendency to outward motion of 

 the object, which tendency is more marked as the depth 

 of immersion, the size, and the departure from the circular 

 form, of the object increase. 



In conclusion, the Author would express his indebted- 

 ness to Prof J. E. Petavel, F.R.S., by whose courtesy he 

 was able to make use of the resources of the Engineering 

 Laboratories of the Manchester University for a part of 

 the experimental work. 



