178 



Sir Norman Lockyer and Mr. F. E. BaxandalL 



it. Thus the same alloy, without being melted, can by heating and 

 chilling have all pattern removed, and by reheating, followed by a 

 not very rapid cool, the pattern can be restored. The constancy in the 

 size of the polygons points to their having been formed at an earlier 

 period in the history of the alloy. 



We see from the above that the patterns of slowly cooled copper-tin 

 alloys are, at all events until they have been confirmed by the examina- 

 tion of chilled portions, entirely misleading as to the separations that 

 occurred during solidification. Even the evidence for the existence of 

 the compound Cu 3 Sn will have to be revised ; although in a somewhat 

 altered form it will probably be found to be satisfactory. 



We hope shortly to present to the Eoyal Society a more complete 

 account of these alloys. 



'■' On the Enhanced Lines in the Spectrum of the Chromo- 

 sphere." By Sir Norman Lockyer, K.C.B., E.E.S., and 

 F. E. Baxandall, A.E.C.S. Received March 19,— Read 

 March 28, 1901. 



In the recently published account* of the spectroscopic results 

 obtained by members of the expedition from the Yerkes Observatory, 

 during the solar eclipse of May 28th, 1900, although the record of the 

 wave-lengths of the lines photographed on the different eclipse plates 

 is of great value, exception must be taken to the method of assigning 

 origins to the lines. This question is so important just now that it is 

 desirable to deal with it without delay. The only origins which 

 Erofessor Frost appears to accept are those given by Eowland to any 

 moderately strong solar line which agrees in position, either exactly or 

 very nearly, with an eclipse line. In discussing the eclipse lines he 

 has made specific allusions to the " enhanced " lines of some of the 

 metals, and to their relationship — or non-relationship — to the eclipse 

 lines. 



On p. 317 he says, " These plates give no evidence of any relation- 

 ship between the bright lines and the ' enhanced ' lines, or lines 

 distinctly more intense in the spark than in the arc spectrum, although. 

 Sir Norman Lockyer has attached much significance to a supposed 

 connection between them. Some of the enhanced lines are present 

 and some are not, or at least were not conspicuous enough for measure- 

 ment." In the paragraph immediately following, he says, "In case 

 of titanium, for which Lockyer gives 48 enhanced lines within 

 our limits, we may summarise the comparison as follows : 17 lines do 



# Frost, 'Ast.-Phys. Journ.,' vol. 12, p. 307, 1900. 



