54 



DR. W. GEOFFREY DUFFIELD ON THE 

 TABLE I. (continued). 



* R & V. = EDER and VALENTA, 'Denksohr. K. Akad. Wiss. Wien,' LXVIIL, 1899. 

 t E. & H. = EXNEB and HASCHEK, 'Sitzber. K. Akad. Wiss. Wien,' CVIL, 1898. 

 J H. W. MORSE, 'Astrophys. Journ.,' 21, p. 225. 

 HUGGINS, 'Phil. Trans.,' 1864, p. 139. 



A few of the above lines were -first observed in comparison spectra taken in 

 conjunction with the pressure photographs and not in the preliminary photographs 

 e.g., 355770 at 30 atmospheres, 4128'80 at 5 atmospheres, 4466'25 at 5 atmospheres, 

 4760-29, 4915-57, and 4934'37 at 40 atmospheres. 



The intensities at the violet end of the spectrum were diminished by the absorption 

 by the glass lens and reflection from the mirrors which prevented ultra-violet light 

 from being used. Similarly the insensibility of the plates to the green part of the 

 spectrum affected the highest wave-lengths. 



Although a large number of lines not chronicled by KAYSER and HUNGE have been 

 noted, one line given by them at 436472, intensity = 1 (maximum = 10), was not 

 seen on any of the above photographs it is possibly due to an impurity. 



3. The Behaviour of the Gold Arc under Pressure: (I) Manipulation. When 

 the arc was first formed at atmospheric pressure between gold poles it burned 



