Shape of Large Bubbles and Drops, 517 



were made by means of a travelling microscope provided 

 with vernier scales running parallel to the x and y axes, and 

 are, unless specified to the contrary, given in centimetres) : — 



Fluid: tap-water. Temp. 8° 0. 



cm 

 p = l gm. per c.c, # = 981—^. 



Mean vertical distance (q) between plane 

 of greatest horizontal section and vertex 

 of bubble, measured on photo = -899 cm. 



Mean maximum diameter of bubble = 11*277 ,, 



Mean diameter of funnel on photo = 12*083 ,, 



Mean true diameter of funnel — 5*413 „ 



T 1 . -899x5*443 

 .*. True value of q= 12 .q 8 3 = "4=051 „ 



T , , 11*277x5*443 t> „.. 



True value of r= ^^.^ = 2*o40 „ 



Hence, employing the equation 



ai 2 = o 2 -*606^- 3 , 

 r 7 



and solving for a x 2 by the method of successive approxi- 

 mations, we find that 



a 1 2 =*1502; 

 and therefore 



m -1502x981 -on* dynes 



1 8 = o =7d , bo- J: . 



I cm. 



This result is in close agreement with the result obtained 

 from measurements of the radii of curvature and pressure of 

 small pendent drops made some time ago by the writer *, 

 which measurements save 



&* 



Tn = 73*4 



■li 



dynes 



cm. 



and is also in substantial agreement with the value obtained 

 recently by Bohr from measurements of the stationary waves 

 formed on a vibrating jet of liquid f. 



We give now an example of the planimetric measure- 

 ments suggested above, choosing, for the purpose of experi- 

 mental illustration, the most difficult case — an application of 



* Phil. Mag. March 1912. 

 t Bohr, /. c. 



