562 Mr. H. T. Jessop on Cornu's Method of 



Table III. Glass 3 a. 



Width of beam =3-25 era. Thickness = '409 cm. 



Bending moment=12 , 3 kg. cm. 



The number of fringes observed in this case was small and 

 consequently the information to be gathered from the results is 

 very little. 



The transverse curvature shows a tendency, however, to in- 

 crease with time, the increase being greater tor the inner and 

 outer fringes. 



The longitudinal curvature also shows a slight increase. 



(Note. — Glasses 3 a, 3 b, and 3 c were cut from the same 

 plate of glass, and have identical dimensions.) 



Table III.— Glass 3 a. 



Transverse Fringes. 



N. 





K A ?i-f-3 2 — ^n)- 





After 1 Minute. 



50 Minutes. 



10 Hours. 



1 



1-236 



1-213 



1-222 



2 



1-245 



1-240 



1-240 



3 



1-288 



1-280 



1-279 





Mean Value 



Mean Value 



Mean Value 





1-256 



1-246 



1-247 



Longitiidi 



no.l Fringes. 





N. 





KA« +5 2 -A, l 2 ). 





1 



475 



•173 



•173 



2 



•172 



•173 



•173 



3 



•174 



•172 



•171 



4 



•173 



•173 



•172 



5 



•172 



■171 



•169 





Mean Value 



Mean Value 



Mean Value 





■1732 



•1724 



■1716 



