LECTURE V- 



I'ELESTIAL MEASURINGS AND WEIGHINGS. 

 " Omnia in numero, pondere, et mensura." 



[ERE are epochs in the history of every great 

 operation, and in the course of every under- 

 taking, to which the co-operations of succes- 

 sive generations of men have contributed 

 (especially such as have received their increments at 

 various and remote periods of history) ; when it becomes 

 desirable to pause for a while, and, as it were, to take 

 stock; to review the progress made and estimate the 

 amount of work done : not so much for complacency, as 

 for the purpose of forming a judgment of the efficiency 

 of the methods resorted to, to do it ; and to lead us to 

 inquire how they may yet be improved, if such improve- 

 ment be possible ; to accelerate the furtherance of the 

 object ; or to ensure the ultimate perfection of its attain- 

 ment. In scientific, no less than in material or social 

 undertakings, such pauses and resumes are eminently 

 useful j and are sometimes forced on our consideration 



