WILLIAM SIEMENS, F.R.S. 319 



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 

 wise at every turn, requiring for their solution not only an inti- 

 mate acquaintance with, but a positive advance upon, electrical 

 science, as established by purely theoretical research in the labora- 

 tory. 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 know- 

 ledge of the nature of the mutual relations between the different 

 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, more- 

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

 the call for new effects, renders former rules Avholly insufficient. 

 In all these 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 admira- 

 tion ; 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 " practititioner 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 practi- 

 tioner, 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 suggestion of 

 Tredgold) defined civil engineering as " the art of directing the 

 great sources of power in nature." 



