ON THE MEASUREMENTS OF WAVE-LENGTHS. 
71 
Tables giving in linear measurements the positions of the fiducial lines on the 
several spectra photographed (continued). 
Spectra to the left. 
Portions 11-18. Measurements in hundredths of an inch. 
(4) 
Fiducial lines.* 
Magnesium. 
Silver. 
Tin. 
Iron. 
Carbon. 
Bismuth. 
Mean. 
XV. 
o-ooo 
o-ooo 
o-ooo 
0-000 
o-ooo 
o-ooo 
o-ooo 
XIV. 
48-625 
48-640 
48-760 
48-650 
48-585 
48-600 
48-650 
XIII. 
98-345 
98-035 
98-260 
98-305 
98-180 
98-350 
98-275 
XII. 
148-925 
148-965 
149-040 
148-965 
148-895 
149-150 
148"965 
XI. 
200-750 
200-590 
200-795 
200-665 
200-860 
200-710 
200-730 
X. 
253-650 
253-620 
253-605 
253-715 
253-500 
253-710 
253-620 
IX. 
308-045 
308-085 
308-090 
308-250 
308-110 
308-150 
308-115 
(5) 
(6) 
Fiducial lines.* 
Tellurium. 
Arsenic. 
Zinc. 
Mean. 
Lead. 
Antimony. 
Mean. 
XV. 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
XIV. 
48-815 
48-705 
48-750 
48-757 
48-685 
48-805 
48-745 
XIII. 
98-730 
98-610 
98-515 
98-670 
98-560 
98-650 
98-605 
XII. 
149-520 
149-500 
149-350 
149-457 
149-320 
149-560 
149-440 
XI. 
201-395 
201-405 
201-250 
201-350 
201-050 
201-380 
201-215 
X. 
254-515 
254-365 
254-450 
254-443 
254-360 
254-250 
254-305 
IX. 
308-975 
308-880 
308-865 
308-907 
308-815 
308-715 
308-765 
(0 
(8) (9) 
Fiducial lines.* 
Indium. 
Thallium. 
Mean. 
Aluminium. 
Copper. 
XV. 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
o-ooo 
XIV. 
49-170 
49-010 
49-090 
48-705 
48-640 
XIII. 
99-055 
99-160 
99-108 
98-310 
98-180 
XII. 
150-205 
150-230 
150-218 
149-065 
148-780 
XI. 
202-320 
202-500 
202-410 
200-970 
200-640 
X. 
255-645 
255-740 
255-693 
254-010 
253-530 
IX. 
310-305 
310-305 
308-340 
308-040 
* These lines were measured in the reverse to the usual order. 
