408 Defcription of 



price, would be almoft equivalent to the expence ; that en-r 

 trufting the management of the firft trials to C. Clouet, 

 would enfure the heft fuccefs ; and laftly, that, in any event, 

 the free and unreferved communication which C. Clouet has 

 made of this difcovery, entitles him to the gratitude of bis. 

 countrymen, and to a national reward. 



XII. Ex trail of a Report made by C. Pictet, of Geneva, 

 to the Society for the Advancement of the Arts efabli/hed 

 in that City in regard to the Steel-Yards of C. Paul. 

 From the Journal des Mines, No. XLV. 



JL HE place of infpe&or of weights and meafures, occu-. 

 pied at Geneva by C. Paul, having given him an opportu- 

 nity of carefully examining a great number of fteel-yards, 

 he has found reafon to be convinced that the greater part of 

 thefe inftruments, and particularly the Roman fteel-yards, 

 are conftruetcd on bad principles, and feem to have been 

 made by artifis unacquainted with the properties of the lever. 

 He has fucceeded in improving thefe inftruments, and fteel- 

 yards in particular. The latter, in the common purpofes of 

 commerce, have two advantages over balances. i . That; 

 their axis of fufpenfion is not loaded with any other weight 

 than that of the merchandife, the conflant weight of the ap- 

 paratus itfelf excepted; while the axis of the balance, be- 

 tides the weight of the iuftrument, fuflains a weight double 

 to that of the merchandife. 2. Theufe of the balance re- 

 quires a confidcrable afibrtment of weights, which caufes a 

 proportional increafe in the price of the apparatus, indepen- 

 dently of the chances of error v\ hicb it multiplies, and of the 

 time employed in producing an equilibrium. '1 hefe motives 

 induced C. Paul to employ his thoughts on the means of fo 

 far improving fteel-yards, that, either in delicate operations 

 of the arts, or in thofe of the fame kind which are often fo 

 neceflary in the practice of the phyfical fcience?, thefe in- 



ftrumentd. 



