XI. A, 4 Witt: Analysis of Babbitt Metal 175 



ard babbitts. A set of several such standards corresponding 

 in general composition to the samples usually submitted for 

 analysis should be on hand and that one selected which closely 

 corresponds to the composition of the sample. As is well known, 

 it is difficult to prepare a babbitt which is sufficiently homoge- 

 neous to serve as a standard. As a rule there is considerable 

 segregation of the materials present, but a standard was made 

 for use in connection with this work which was satisfactorily 

 uniform. Pure lead, antimony, tin, and copper were obtained 

 and turned over to an expert in making alloys. The metals 

 were mixed in the following proportions : Lead, 85 per cent ; 

 antimony, 12 per cent; tin, 2 per cent; copper, 1 per cent. The 

 alloy was cast in the form of a small cylinder about 3.5 centi- 

 meters in diameter by 10 centimeters long. The samples were 

 taken with a hack saw at various points in the cylinder and 

 analyzed separately, in duplicate. The results showed the metal 

 to be uniform. After preparing a quantity of the standard, 

 uniform in fineness and composition, portions may be weighed 

 with the samples and carried through the various operations. 

 Especially in the tin and colorimetric copper determinations it 

 is well to have both standard and sample as nearly as possible 

 of the same composition. 



