190 SCIENTIFIC APPARATUS. 



It is not a little remarkable that the very men who have written 

 so learnedly, but have done so little to advance the progress of 

 general mechanics, and whose failure may be traced to their 

 pursuit of theory without continually recurring to practice and 

 observation, have in one branch which may properly be classed 

 therewith, namely, astronomy, pursued a totally different course, 

 and achieved the most splendid results. In astronomy theory and 

 practice have gone hand in hand. Those who have worked out 

 and completed the marvellous intellectual bequest of Newton 

 have given to their studies a vitality and a force which can only 

 be evolved when the means of observation and the patience to 

 observe move side by side with the advance of the theoretical 

 reasoner. 



The prediction of the position of an unknown planet by calcu- 

 lations based upon disturbances which were observed to exist and 

 were previously not accounted for, is a triumph of the intellect 

 which all countrymen of a discoverer contemplate with satisfac- 

 tion ; and here at least no one can say that theory and practice 

 are not in perfect accord. Happily the time is fast approaching 

 when in mechanics, as well as in all other sciences, theory and 

 observation will be inseparably coupled together ; and an exhibi- 

 tion such as that now taking place cannot fail to exercise an 

 important influence in confirming and consolidating such a result. 



Granted that those who in recent years have invented and 

 developed the machinery of our workshops, that such men as 

 Whitworth, Clement, and Roberts, have laboured without any 

 assistance from abstract theoretical knowledge, and with the 

 help only of their own natural genius in reasoning logically 

 upon what they have observed; granted that the creative minds 

 of Watt, Telford, and Stephenson, although never trained to the 

 study of mathematics, have given us our steam-engines, our canals, 

 and our railways \ and it must surely be conceded that there is an 

 enormous field of useful mechanical knowledge in which a man 

 may work successfully for the good of others without being com- 



