General Results obtained from 1898 Eclipse Spectra. 7 



ordinary solar spectrum. The lines were measured and identified 

 for the purpose of facilitating the reduction of the bright line spectra 

 obtained during totality. 



Spectrum No. 3 was exposed for four seconds, beginning two seconds 

 before second contact. In this the flash spectrum is fully developed, 

 and extends from A 3340 to A 6000. The majority of the bright 

 arcs, including those due to the upper chromosphere, extend over 40° 

 of the limb, implying a depth of l" - 3 for the gases composing this 

 layer. The total depth of the chromosphere deduced from the 

 hydrogen arcs is S"'2, and from the calcium arcs ll"-6. There are 

 313 measurable lines in this negative, and the wave-lengths and 

 identifications of these are given in Table I. 



. Spectrum No. 4, exposed for half a second shortly after second 

 contact, gives the spectrum of the upper chromosphere and pro- 

 minences. Seven of the latter are shown. The images are about 

 equally dense in calcium radiations, although in hydrogen there is a 

 marked variation of intensity between the different prominences. 



A conspicuous feature in the spectrum of two of the prominences is 

 a band of continuous spectrum, beginning at A 3668 near the end of 

 the hydrogen series, and extending indefinitely in the ultra violet. 



Good measures were obtained of the images of a small prominence 

 at the centre of the plate, the wave-lengths being given in Table II. 



Spectrum No. 5. — This plate had a long exposure near mid-totality. 

 The continuous spectrum of the corona is strongly marked, and the 

 green corona line is well shown at position angles 60° to 78°, and 95° 

 to 105°. A new corona line is faintly impressed at A 3388 ± , the 

 maxima of intensity being at the same position angles as those of the 

 green line. 



Spectrum No. 7 shows the re-appearing arcs of the flash spectrum, 

 the exposure ending about four seconds before third contact. The 

 green corona line is shown on both east and west limbs, and there is 

 a faint corona line near H. The wave-length values of the lines 

 measured on this plate are given in Table I. 



Spectrum No. 8. — This was exposed almost at the instant of third 

 contact, the re-appearing photosphere showing as four narrow bands of 

 continuous spectrum due to Baily's beads. The flash spectrum arcs 

 extend between and across the bands, and can be traced over an arc of 

 55°, the depth of the layer, in this case exceeding 2". 



The focus in this negative is poor, and no measures were made ; but 

 as far as can be judged, comparing this plate and No. 3, the spectra of 

 the east and west limbs of the sun are identical. 



Spectra Nos. 9 and 10. — These are cusp spectra, very similar to 

 Nos. 1 and 2. 



