I 



ADDRESS. 3 



The advancement of the last fifty years has, I venture to submit, 

 rendered theory and practice so interdependent, that an intimate union 

 between them is a matter of absolute necessity for our future progress. 

 Take, for instance, the art of dyeing, and we find that the discovery of 

 new colouring matters derived from waste products, such as coal-tar, 

 completely changes its practice, and renders an intimate knowledge of 

 the science of chemistry a matter of absolute necessity to the practitioner. 

 In telegraphy and in the new arts of applying electricity to lighting, to 

 the transmission of power, and to metallurgical operations, problems 

 arise at every turn, requiring for their solution not only an intimate 

 acquaintance with, but a positive advance upon, electrical science as 

 established by purely theoretical research in the laboratory. In general 

 engineering the mere practical art of constructing a machine so designed 

 and proportioned as to produce mechanically the desired effect, would 

 suffice no longer. Our increased knowledge of the nature of the mutual 

 relations between the difierent forms of energy makes us see clearly 

 what are the theoretical limits of effect; these, although beyond our 

 absolute reach, may be looked upon as the asymptotes to be approached 

 indefinitely by the hyperbolic course of practical progress. Cases arise, 

 moreover, where the introduction of new materials of construction, or the 

 call for new effects, renders former rules wholly insufiicient. In all theso 

 cases practical knowledge has to go hand in hand with advanced science 

 in order to accomplish the desired end. 



Far be it from me to think lightly of the ardent students of nature, 

 who, in their devotion to research, do not allow their minds to travel into 

 the regions of utilitarianism and of self-interest. These, the high priests 

 of science, command our utmost admiration ; but it is not to them that we 

 can look for our current progress in practical science, much less can we 

 look for it to the ' rule of thumb ' practitioner, who is guided by what 

 comes nearer to instinct than to reason. It is to the man of science 

 who also gives attention to practical questions, and to the practitioner 

 who devotes part of his time to the prosecution of strictly scientific 

 investigations, that we owe the rapid progress of the present day, both 

 merging more and more into one class, that of pioneers in the domain of 

 nature. It is such men that Archimedes must have desired when he 

 refused to teach his disciples the art of constructing his powerful ballistic 

 engines, exhorting them to give their attention to the principles involved 

 in their construction, and that Telford, the founder of the Institution of 

 Civil Engineers, must have had in his mind's eye, when he (at the sug- 

 gestion of Tredgold) defined civil engineering as ' the art of directing the 

 great sources of power in nature.' 



These considerations may serve to show that although we see the men 

 of both abstract and applied science group themselves in minor bodies for 

 the better prosecution of special objects, the points of contact between 

 the difierent branches of knowledge are ever multiplying, all tending to 

 form part of a mighty tree— the tree of modern science— under whose 



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