26 



PROFESSOR A. FOWLER, F.R.S., ON 



other view than that we see the stars in order of temperature, and 

 that our sun once had a higher temperature, and that that tempera- 

 ture is gradually and slowly falling. 



The subject thus presented to us is one of the greatest philosophic 

 interest. We find in the stars, in the main, the same substances 

 which are found upon the earth, and we have good hope that we 

 shall yet find — perhaps in Professor Fowler's laboratory — the 

 remainder of the unknown substances represented in the spectra of 

 the stars and nebulae. The final conclusion is that the stars differ 

 from one another greatly in temperature, but are composed of the 

 same substances as the sun and earth. 



Mr. Walter Maunder rose to propose a vote of thanks to 

 Professor Fowler not only for the high value of the lecture, but for 

 the personal sacrifice which had been involved in his delivering it to 

 them. Professor Fowler was a very busy man, and of his two 

 assistants, one had recently enlisted and the other was ill at the 

 present time, so that Professor Fowler was single-handed. He has 

 himself borne a large and very important part in the marvellous 

 discoveries which have been made by means of the spectroscope, 

 and only a fortnight ago the Royal Astronomical Society gave him 

 its gold medal ; nor has that medal ever been more worthily 

 bestowed. Of all the discoveries made during the last hundred 

 years, those made in connection with the spectrum have been the 

 most fascinating and romantic of all, if, perhaps, we except the 

 decipherment by Eawlinson and others of the cuneiform inscrip- 

 tions, whereby a crowded mass of wedge-shaped dents were revealed 

 as written languages, and made to yield up their meaning. The 

 reading of the language of the lines of the spectrum is not less 

 striking; indeed, in one respect it is more striking still, for the 

 rainbow, which is the typical example of the spectrum as we find it 

 in nature, shows no lines — these had to be discovered. The story, 

 therefore, reminds us of the romance of the " Gold Bug," told by 

 Edgar Allan Poe. There the cryptogram to be interpreted was 

 written in invisible writing, which had first to be brought to light 

 and afterwards deciphered. 



One research of great interest in which Professor Fowler had 

 borne an important part was the interpretation of a series of 

 hydrogen lines first noted in the spectrum of a somewhat faint star 

 in the southern hemisphere. The hydrogen lines given by the great 



