W. P. White — Melting Point Determination. 473 



side of the charge, troublesome with large charges, negligible 

 with small. Second, due to various irregularities in heat flow, 

 less with narrow charges and small thermoelements, hardly 

 ever over a degree or two. Third, due to conduction of heat 

 down the thermoelement, also less with narrow charges and 

 small thermoelements, for which it is usually negligible ; but 

 possibly amounting to several degrees with inclosed elements. 



7. Electrical conductivity in the melt produces an error in 

 the reading of bare thermoelements, thus far negligible in 

 small charges of salts. 



8. Contaminated elements, besides reading false, read so as 

 to increase obliquity. 



9. Differentiation and diathermancy of the charge probably 

 increase obliquity. 



10. Meltings have been made above 800° agreeing with each 

 other to '05°. In most cases an experimental obliquity 

 remains of from *5° to 1*5° (at high temperatures) whose cause 

 is still to be definitely determined. 



Geophysical Laboratory, Carnegie Institution of Washington, 

 Washington, D. C, July 15, 1909. 



