USEFUL TO THE MICKOSCOPIST 1135 



Multiples of any of the above may be obtained in the same manner as 

 in the preceding example. 



Thus, if the diameter of the circle = ^ ^ inch, then the square of 3 being 



9 and '7854 x 9 = 7'0686 sq. ^ inch and -05067 x 9 = -45603 sq. millimetre, 

 is the area required. 



Volumes of Spheres 



$ in. diameter. = 1-02266 cubic ^ inch = 16-75835 cubic millimetres. 



ft . = -52360 = 8-58024 



T V -30301 = 4-96543 



T*TT i - '52360 ^ = -00858 



TT&iT" = '52360 T$nr =8580-24 /t 



1 mm. diam. . . . = -52360 cubic mm. = 31-952 cubic T u inch. 



100^ ... =523600-0 p. =31-952 TT JW 



10 n . . . = 523-60 = -03195,, 

 M . . . = -52360 = -00003195 



Multiples of any of the above follow the preceding example of cubic 

 measures. Thus, if the diameter of the sphere = 30 /*, then the cube of 3- 

 being 27 and 523-6 x 27 = 14137-2 cubic ^ and -03195 x 27 = -86265 cubic T ^. 

 inch, is the volume required. 



