RADIATION IN ABSOLUTE MEASURE AT VERA LOW TEMPERATURES. 355 
14. The results obtained were plotted as a curve, taking the sum of the galvano¬ 
meter readings as ordinates, and the difference of temperatures between the thermo¬ 
junctions as abscissae. From this curve the temperatures corresponding to the 
observed galvanometer deflections were read off when it was required to convert 
thermojunction readings to temperatures on the Centigrade scale. 
This curve was plotted on a large scale on a table covered with a sheet of plate 
glass, 4 feet 6 inches by 3 feet 6 inches, ruled in 10-centimetre squares. The glass 
plate was not wholly covered with squared paper; those squares only through which 
the curve passed were filled in. The smallest division of the squared paper is equal 
to 1 mm., and this corresponds to 0T° C., or one scale division of the galvanometer. 
15. The results of confirmatory experiments, made after intervals of months, agreed 
with absolute accuracy; which showed that both the thermojunctions and the 
galvanometer were quite constant. 
2 z 2 
