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The Level-trier. 



Apparatus used in the manufacture of spirit-levels to try the character and approximate 

 enftitiveneng of the curvature ground in the glass tubes before they are finally filled and 

 sealed. Also to accurately determine the value of one division of level in seconds of are. 



C. L. Berger & Sons' Auxiliary Apparatus. 



Used during the construction of their Instruments of Precision 



