KENT AND AVERY. — WAVE-LENGTHS OF TITANIUM. 



TABLE I -continued. 



Plates : Seed " Gilt Edge," No. 27. 



Developer : Metol, adurol, liydroeLinon. 



Second order spectrum. 



Width of slit: 025 to 0.050 mm. ; length : 5 mm. 



Length of grating lines : 14 mm. 



357 



