KENT AND AVERY. — WAVE-LENGTHS OF TITANIUM. 



357 



TABLE I -continued. 



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



Developer: Metol, adurol, hydroehinon. 



Second order spectrum. 



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



Length of grating lines : 14 mm. 



