February 6, 1896] 



NATURE 



319 



THE STORY OF HELIUM} 

 Prologue. 



DURING the last decade, as most of you know, our 

 literature has been enriched by a recrudescence of 

 ( the short story, generally dealing with very modern 

 human affairs of various kinds from many different 

 standpoints. 



But these modern stories, and others that might be 

 referred to, are not the only ones now available. During 

 the last sixty years Egypt, Babylonia, and other countries 

 which might be named, now here and now there, have 

 supplied us with other stories — most precious indications 

 which enable us to study, into a far-reaching past, the 

 beginnings of man's history. These stories, as you also 

 know, were not very easily deciphered — they were all of 

 them hidden away in strangest script ; but the hiero- 

 glyphics and cuneiform characters, which at first seemed 

 to have absolutely no meaning whatever, have bit by bit 

 been unravelled by the genius of linguistic explorers, 

 until at length we may say that the students of Archae- 

 ology are in possession of more or less complete histories 

 of the most ancient peoples of the world. 



All these histories have not yet been completely written ; 

 but my point is that they have been begun, and that even for 

 the beginning of them the greatest skill has been required 

 to transmute the strange hieroglyphics which were first 

 employed by ancient peoples into modern equivalents, so 

 that we can understand what they wished to convey. 

 Here we are in presence of man's earliest attempt at any 

 language ; but the story which I, your President, have to 

 tell you to-night, has a very different origin to this, for 

 the reason that, although it is a story, and written, it is 

 true, in hieroglyphics, the hieroglyphics are of nature's 

 invention, and not man's. 



The story or fairy tale of science, which has placed us 

 in possession of the most precious truths regarding every 

 star which shines in space, is a story written in nature's 

 hieroglyphics in every ray of light which reaches this 

 I planet of ours from the tiniest star. 



Now, of course in the hour at my disposal to-night it 

 is impossible for me both to tell you a story, and spend 

 much time upon the alphabet in which the story is written, 

 but there are just one or two words about the alphabet 

 that may be useful. One key to these hieroglyphics, 

 this light story, which is hidden in every ray of light, is 

 supplied to us by the rainbow, which teaches us that the 

 white light with which nature bountifully supplies us in 

 sunlight, is composed of rays of different kinds or of 

 different colours. Many of you know that there is an 

 almost perfect analogy between these coloured lights and 

 sounds of different pitches. 



The blue of the rainbow may be likened to the higher 

 notes of the key-board of a piano, and the red of the 

 rainbow, on the other hand, may be likened to the longer 

 sound waves, which produce the lower notes ; and as we 

 are able in the language of music to define each particular 

 note, such as B flat and G sharp, and so on, so in these 

 celestial hieroglyphics we are enabled to do exactly the 

 same thing with perfect definiteness, by considering the 

 wax e-length of the particular colour with which we have 

 to deal, so that having these wave-lengths we may deter- 

 mine the quality of every kind of light which reaches 

 the human eye, whether from a terrestrial light source, 

 the sun or any other celestial body, including the shoot- 

 ing stars which some of us are hoping to see to-night. 



Well, the result of the study of this hieroglyphic 

 language has been that we can in that way determine the 

 chemical source of every light of different colour which 

 can be thus examined in any celestial body, provided 

 always we can obtain the same light-note from some 

 terrestrial substance when we experiment upon them at 



1 Presidential Address, Vesey Club, Sutton Coldfield, November 12, 1895, 

 l.y Prof. J. Norman Lockyer, C.B., F.R.S. 



NO. 1 37 I, VOL. 53] 



temperatures high enough to set them glowing in our 

 laboratories. We can determine therefore, by such means, 

 whether in different parts of space we have the same 

 chernical substance, or whether in different stars we are 

 dealing with substances perfectly and completely distinct. 



Imagine these hieroglyphics, then, more or less trans- 

 lated, on the principle I have indicated to you, by the 

 labours of Kepler, Newton, Fraunhofer, and other later 

 workers ; so that in the case of anything shining any- 

 where, we can eventually find out something about its 

 chemical and its physical constitution. 



Another part of the prologue, before I begin my first 

 chapter, brings us to another line of study, that is to say, 

 the telescopic and visual observations of heavenly bodies. 



I take you back to the year 1706, when there was a 

 total eclipse of the sun, visible in Switzerland, and there 

 was one Stannyan, who gave an account of what he saw 

 at Berne. After describing the phenomena of the eclipse 

 he wrote, referring to the sun : " His getting out of his 

 eclipse was preceded by a blood-red streak of light." 

 Of course, in the prephotographic days no autobio- 

 graphical record of that particular eclipse was obtainable, 

 but we possess photographic records of other similar 

 later eclipses, which may be taken as representing what 

 Stannyan saw, for, in all, the blood-red streak referred to 

 by him has been seen. 



The phenomena photographed in all eclipses now-a- 

 days indicate to us Stannyan's observation, for in all, 

 certainly the sun, in getting out of his eclipse, is pre- 

 ceded by a blood-red streak of light, which we now know- 

 to represent one of the solar envelopes to which I gave 

 the name of chromosphere in 1868. 



Here then ends the prologue, and I begin the first 

 chapter of my story. 



Chapter I. 



In the year 1868, the new alphabet to which I have 

 referred was first utilised in endeavouring to unravel the 

 message which was conveyed to us by a most interesting 

 eclipse observed in India. The "blood-red streak" was 

 now subjected to minute analysis, because practically the 

 spectroscope was now first utilised. The diagrams will 

 indicate the kind of record with which we have to deal in 

 studying these celestial hieroglyphics. We are in one 

 part dealing with the long waves of light, the red ; we 

 are in the other dealing with the shorter waves of light, 

 the blue. The work ^done in that eclipse is indicated 

 by the bright lines — the hieroglyphics — which, when 

 translated as they have been, describe for us the chemical 

 nature of the particular stuff in the sun, which made him 

 put on a blood-red appearance " on his getting out of his 

 eclipse." Taking the notes in the light scale which are 

 lettered in the ordinary spectrum of light, chiefly sun- 

 light, in order that they may be easily recognised and 

 remembered, we learn the particular qualities of the light 

 emitted by the blood-red streak. 



We have one quality represented by the line D, another 

 at C, and another at F. Hence the observers in 1868 

 could tell us very much more about the particular 

 chemical substances which were present in that blood-red 

 streak than Stannyan could, because spectroscopy had not 

 been invented in his day. According to the diagram 

 (Fig. i), one of the lines is in the position of D. One 

 observer said it was " at D, or near D," and almost the 

 whole of my story depends upon that distinction. 



Soon after this eclipse was observed in India, a method, 

 long before suggested, of studying the blood-red streak 

 surrounding the sun without waiting for an eclipse was 

 brought into operation. 



By this method it was quite easy to make observations, 

 whenever the sun was shining, perfectly free from any of 

 the difficulties attending the hurry and the worry and the 

 excitement of an eclipse, which lasts only a few seconds. 



Further, as the method consists of throwing an image 



