766 



PLATE IX. 



Fig. 111. A weighing machi»c. The platform sup. 

 porting the weight rests on the pins A,B,C, D, at 

 equal distances from the fulcra E,F,G,II; so that 

 wherever the weight may be placed, it presses equally 

 ou the lever IK, at L, and is counterpoised by a much 

 smaller weight placed in the scale M. P. 126. 



Fig. 112. A steelyard resembling that of Mr. Paul, 

 in which different weights may be employed. A, a 

 loop to check the vibrations; B a scale to be sus" 

 pended by the hook C. If great delicacy be required 

 in the weiglits, the fractional parts may be expressed 

 by the turns of a micrometer screw D, furnished with 

 an index. P, 126. 



Fig. 113. A bent lever balance. P. 127. 



Fig. 1 14. A spring steelyard : half the case being 

 removed, to show the spring. P. 127. 



Fig. 115. A B, the path of the centre of gravity of 

 the human body, such as it would be described in 

 walking, if the legs were inflexible. C D, the path de- 

 scribed in running, on the same supposition. P. ISO. 



Fig. lie. The actual path of the centre of gravity, 

 •s it is usually described. P. 130. 



Fig. 117. An elastic column, compressed by a weight 

 acting at the distance of one third of its depth from 

 the concave surface; the compression being every 

 where as the distance of the lines A B, A C. P. 139. 



Fig. 118. An elastic column, extended by a weight 

 acting at the distance of one third of its depth from 

 the convex surface, the extension being every where 

 as the distance of A B, A C. P. 139. . 



Fig. 119. An elastic column, compressed by a weight 

 acting immediately on the concave surface : the com- 

 pression extends only to the line A B, the parts beyond 

 this line being extended. P. 139. 



Fig. 120. A column bent, by a weight acting lon- 

 gitudinally, into the form of a harmonic cur\e: the 

 line A B C D is the limit between the parts which are 

 compressed, and those which are extended. P. 139. 



Fig. 121. An elastic plate or rod, considerably bent 

 by a weight acting at its extremity. P. 139. 



Fig. 122. An elastic rod fixed at one end, and bent 

 by its own weight. P. 139. 



Fig. 123. An elastic rod supported at each end, and 

 bent by its own weight. P. 139. 



