DR. C. W. SIEMENS* ADDRESS. 205 



in every branch of this Exhibition but for the great power given to 

 man through the mechanical inventions just referred to. Yet, were 

 mechanical science at these Conferences to be limited to the objects 

 exhibited in the South Gallery (and separated unfortunately from 

 apparatus representing physical science by lengthy corridors filled 

 with objects of natural history), we should hardly find material worthy 

 to occupy the time set apart for us. But, thanks to the progress of 

 opinion in recent days, the barrier between pure and applied science 

 may be considered as having no longer any existence in fact. We see 

 around us practitioners, to whom seats of honour in the great 

 academies and associations for the advancement of pure science are 

 not withheld, and men who, having commenced with the cultivation of 

 pure science, think it no longer a degradation to follow up its applica- 

 tion to useful ends. 



The geographical separation between applied science and physical 

 science just referred to, must therefore be regarded only as accidental, 

 and the subjects to be discussed in our section comprise a large pro- 

 portion of the objects to be found within the rooms assigned more 

 particularly to physics and chemistry. Thus, all measuring instru- 

 ments, geometric and kinematic apparatus, have been specially 

 included within our range, and other objects such as telegraphic 

 instruments, belong naturally to our domain. 



With these accessions, mechanical science represents a vast field 

 for discussion at these Conferences, a field so vast indeed that it would 

 have been impossible to discuss separately the merits of even the 

 more remarkable of the exhibits belonging to it. It was necessary 

 to combine exhibits of similar nature into subdivisions, and the Com- 

 mittee have asked gentlemen eminently acquainted with these branches 

 to address you upon them in a comprehensive manner. 



Thus they have secured the co-operation of Mr. Barnaby, the 

 Director of Construction of the Navy, to address you on the subject 

 of Naval Architecture, and of Mr. Froude to enlarge upon the subject 

 of fluid resistance, upon which he has such an undoubted right to 

 speak authoritatively, Mr. Thomas Stevenson, the Engineer of the 

 Northern Lighthouses, will describe the modern arrangements of 

 Dioptric lights, which mark a great progress in the art of lighting up 

 our coasts. Mr. Bramwell has undertaken the important task of 



