Di Bella 



^^ '\p„M 



/■"> ^ i 



a;vo.(7orr! -'-i 



Fig. 1 - Rotatory motion of a 

 mass around a point 



that each window have as its contour the trajectory described by P , which is also 

 the intersection of a hemisphere with a cylinder of circular section, having the 

 ray of the sphere as its diameter.) 



The device was tested extensively on the ground and on the surface of the 

 water with satisfying results on the whole. 



Continuing our study, we thought it suitable to release the extremity of arm 

 A from the center o and to insert between a and o an arm r = OA . Thus we 

 obtained the device indicated in Fig. 2 which represents a mass that turns 



around an axis, with the latter rotating around 

 another axis. The mass moves on a sphere of 

 ray r^ = (r^ + r^)^-^^. The device, which may 

 be considered the basis of the present paper, 

 is formed as follows. 



On a light base (1) posed on a horizontal 

 plane, a motor is placed (2) which, by means 

 of a transmission (3), turns the horizontal 

 shaft (4) that is held up by two supports (5) 

 and (6) attached to the base. The shaft has a 

 collar (7) within which can rotate an arm 

 oAq = r , which has welded in Aq at 90° an- 

 other arm Aq Pq = R> at whose extremity p^ 

 is concentrated a mass m. There are also 

 two toothed conical wheels of equal diameter 

 (not designated in the figure), one connected 

 to arm 0A„ and the other connected to one of 



Fig. 2 - Rotation of a 

 mass around an axis, 

 with the latter rotating 

 around another axis 



1374 



