xii PREFACE. 



The views which I have put forward, as being what I 

 honestly believe to be the true outcome of the seventeen years' 

 work which I have done, depend for their strength upon the 

 convergence of very various lines of thought and work, and I 

 show in a concluding chapter that they appear to correlate the 

 various physical phenomena presented by the sun's surface. 



No doubt the future progress of science will show that we, 

 after all, are looking through a glass darkly, and are not yet 

 face to face with the whole truth. We must all of us be content 

 to have our work criticised and expanded by future work ; by 

 researches carried on with greater skill ; with more elaborate 

 methods and higher views; while it is certain that we shall 

 get a much higher and much richer truth out of further 

 inquiries. 



It is necessary that I should state in conclusion, that without 

 the aid afforded by the organisation of the Committee on Solar 

 Physics, the observations on sun-spot spectra referred to in 

 chapter xxiii., and on which are based the views detailed in 

 the concluding one, could never have been made. 



J. NORMAN LOCKYEK. 



December, 1886. 



