error which it lias been found most difficult to guard against in the use of the furnace is altogethcr avoided.
Te inethod brietly outlined in this paper possesses the following advantages over inethods hitherto practiced for the calibration of thermoelements and for the detennination of the meltingpointsof certain metals.
(1) The use of the air thermometer is avoided.
(•Z) The cnmbersome and laborious procedure of fusing the metals in eonsiderable masses witliin a fnrnace is rendered unnecessary and the difficulty of bringing the melted me tal and the jnnction of the thermoelement to precisely the same temporature is eliminated.
(3) The elaborate precautions necessarv to prevent the vitiation of the jnnction bv the action of fumes, which constitutes one of the chief difficnlties of sucli work wlien a fnrnace is used is avoided.
(t) The amonnt of metal which is necesan to use in detennining melting points or in calibrating a thermo-element is mucli smaller in this than in the inethods usually einployed.
The accuracy of the inethods described is believed to be fully equal to that of other known methods of calibration.
Physical Laboratory of Cornell University.