Manchester Memoirs, Vol. lix. (191 5), No. 11. 5 



fluence on human thought, but they have given birth 

 to innumerable inventions which have augmented our 

 power, and bettered the conditions of our existence. This 

 highway of human progress continues across the revolu- 

 tions of centuries, like a thread of gold, consolation for 

 the sad spectacle offered by the history of kings and 

 factions. 



It is true that the development of science has known 

 periods of decadence and arrest. It is true that scientists 

 have allowed us to see in their work the influence of the 

 environment in which they lived. Doubtless it has 

 chanced that the fruits of long labour have been 

 destroyed, — as example the burning of the library of 

 Alexandria. Doubtless the care of immediate material 

 interests has often intervened, sometimes in favour of 

 progress, but in the majority of cases to delay its march. 



True it is that the evolution of exact and natural 

 sciences has been subject to the ordinary rules of his- 

 torical development, but here we become aware of a 

 superior tireless force, always victorious, and always 

 bringing us back to the path of progress. This creative 

 force constitutes one of the most important factors in the 

 history of humanity. 



We would endeavour to emphasise the progressive 

 action of this force and its historical influence by recalling 

 in a few words the work accomplished by certain men 

 of science taken as examples. 



Let us first take Archimedes, one of the most in- 

 genious scientists of ancient Greece. 



ARCHIMEDES was born at Syracuse in Sicily about 

 287 B.C. The son of a Pheidias, a learned astronomer, 

 he was well prepared for scientific work, and moreover, 

 he studied at the famous school of Alexandria in Egypt. 



