ILLUSTRATIONS. 



FIG. 



PAGE 



104. Sun's Atmosphere 



105. Part of the Spectrum of a Sun-spot observed at Greenwich . . .311 



106. Map showing the most widened Lines observed in Sun-spots in ten 



Observations taken from three Different Periods .... .316 



107. Number of Appearances of Known and Unknown Lines . . . 325 



108. Intensities of Iron (Thalen) compared, with the Iron Lines seen in 



Prominences (Young) 332 



109. Anomalous Reversals (iron) 334 



110. Portion of a large Map showing how the Iron Lines most affected in 



Sun-spots are Recorded. Region b D 337 



111. Portion of a large Map showing how the Iron Lines most affected in 



Sun-spots are Recorded. Region F b 339 



112. Frequencies of Appearances of Iron Lines 341 



113. Iron Spot Lines confronted with Iron Prominence Lines 342 



114. Tacchini's Observation of New Prominence Lines 344 



115. Different rates of Motion registered by different Iron Lines 349 



116. Diagram showing the behaviour of certain Iron Lines 351 



117. Showing how Spot Lines will be Brightest on one Hypothesis and not 



on the other 357 



118. The Lines seen in the Egyptian Observations 363 



119. Basic Lines in Spots and Prominences 373 



120. Hypothetical Section of the Solar Atmosphere 403 



121. Wellings-up of Metallic Strata 413 



122. Tree-like Prominences 415 



123. Metallic Prominence (Young) 416 



124. Diagram summarising the Results of the Italian Observations for the 



years 1881 83 419 



125. Curve showing the Varying Motions of the Spots in Longitude .... 425 



126. Spb'rer's Curves of the Latitude of Sun-spots 430 



127. Observations of the Phenomena at the Sun's North Pole, 1878 (Lockyer) 432 



128. The Appearances presented by the Sun's Poles in the American Photo- 



graphs 432 



129. Sporer's Curve of Spotted Areas 434 



130. Combination of Sporer's Curves 435 



131. The Eclipse of 1858, showing Cones 437 



132. Newcomb's Observations, 1878 439 



133. The Corona of 1867 440 



134. Tracing of the Photographs, Eclipse 1878 442 



