70 Dr. Moll on the Comparison of 



full and complete information as to the means by which the 

 kilogramme was determined. The coincidence of the experi- 

 ments on the length of the pendulum made by Captain Kater 

 and Monsieur Biot affords sufficient evidence of the accuracy 

 with which these operations were conducted ; but how the 

 kilogramme was come by, has never been very satisfactorily 

 explained. Indeed, M. Delambre, in the ' Base du Systeme 

 Metrique,' having explained how the metre was determined, 

 says, that the account of the fixation of the unit of weight 

 ought to have followed ; but that 'the multiYarious avocations 

 of Mr. Lefevre Gineau, as professor, as an inspector of 

 studies, and finally as a member of the legislative chamber, 

 did not allow him sufficient leisure to lay the finishing hand to 

 the arrangement of his papers, although the plates were en- 

 graved long ago. In consequence, not the particulars of the 

 experiments, but the account of what was done, as drawn up 

 by Tralles, is given as it was read before the Institute. But 

 this is a report of the experiments, not the description of the 

 experiments themselves ; we have the shadow, not the thing 

 itself, and we are entirely in the dark as to the particulars of 

 so interesting and intricate an operation as the determination 

 of the unit of weight. 



It must be observed that the operations by which the kilo- 

 gramme was determined were closed in 1799, and that M. 

 Delambre's evidence as to the supineness of M. Lefevre Gineau 

 is given in 1810. Thus, in eleven years M. Lefevre could not 

 spare time for a work so important, and on which his scientific 

 reputation was chiefly to rest : for it must be recollected, that 

 great as the merit of M. Lefevre as a legislator and as an 

 inspector of the University possibly might have been, he has 

 not attached his name to any other scientific operation than 

 the determination of the kilogramme. All this would certainly 

 have been entirely different if the ingenious and lamented 

 Borda, who was the soul of all the operations for determining 

 the metre and kilogramme, had not been untimely snatched 

 away. But, taking the matter as it stands now, it must be 

 confessed, that we know very little of the means by which the 

 unit of weight was determined. 



But whatever is the degree of uncertainty prevailing about 



